Update jsconfig.json and package.json to correct open-sse path references from relative to local directory.

jsconfig.json

@@ -3,8 +3,8 @@
     "baseUrl": ".",
     "paths": {
       "@/*": ["./src/*"],
-      "open-sse": ["../open-sse"],
-      "open-sse/*": ["../open-sse/*"]
+      "open-sse": ["./open-sse"],
+      "open-sse/*": ["./open-sse/*"]
     },
     "module": "ESNext",
     "moduleResolution": "bundler"

open-sse/.npmignore

@@ -0,0 +1,8 @@
+node_modules/
+*.log
+.DS_Store
+test/
+*.test.js
+.env
+.env.*
+

open-sse/config/constants.js

@@ -0,0 +1,209 @@
+// Provider configurations
+export const PROVIDERS = {
+  claude: {
+    baseUrl: "https://api.anthropic.com/v1/messages",
+    format: "claude",
+    headers: {
+      "Anthropic-Version": "2023-06-01",
+      "Anthropic-Beta": "claude-code-20250219,oauth-2025-04-20,interleaved-thinking-2025-05-14,fine-grained-tool-streaming-2025-05-14,context-management-2025-06-27",
+      "Anthropic-Dangerous-Direct-Browser-Access": "true",
+      "User-Agent": "claude-cli/1.0.83 (external, cli)",
+      "X-App": "cli",
+      "X-Stainless-Helper-Method": "stream",
+      "X-Stainless-Retry-Count": "0",
+      "X-Stainless-Runtime-Version": "v24.3.0",
+      "X-Stainless-Package-Version": "0.55.1",
+      "X-Stainless-Runtime": "node",
+      "X-Stainless-Lang": "js",
+      "X-Stainless-Arch": "arm64",
+      "X-Stainless-Os": "MacOS",
+      "X-Stainless-Timeout": "60"
+    },
+    // Claude OAuth configuration
+    clientId: "9d1c250a-e61b-44d9-88ed-5944d1962f5e",
+    tokenUrl: "https://console.anthropic.com/v1/oauth/token"
+  },
+  gemini: {
+    baseUrl: "https://generativelanguage.googleapis.com/v1beta/models",
+    format: "gemini",
+    clientId: "681255809395-oo8ft2oprdrnp9e3aqf6av3hmdib135j.apps.googleusercontent.com",
+    clientSecret: "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"
+  },
+  "gemini-cli": {
+    baseUrl: "https://cloudcode-pa.googleapis.com/v1internal",
+    format: "gemini-cli",
+    clientId: "681255809395-oo8ft2oprdrnp9e3aqf6av3hmdib135j.apps.googleusercontent.com",
+    clientSecret: "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"
+  },
+  codex: {
+    baseUrl: "https://chatgpt.com/backend-api/codex/responses",
+    format: "codex",
+    headers: {
+      "Version": "0.21.0",
+      "Openai-Beta": "responses=experimental",
+      "User-Agent": "codex_cli_rs/0.50.0 (Mac OS 26.0.1; arm64)"
+    },
+    // OpenAI OAuth configuration
+    clientId: "app_EMoamEEZ73f0CkXaXp7hrann",
+    clientSecret: "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",
+    tokenUrl: "https://auth.openai.com/oauth/token"
+  },
+  qwen: {
+    baseUrl: "https://portal.qwen.ai/v1/chat/completions",
+    format: "openai",
+    headers: {
+      "User-Agent": "google-api-nodejs-client/9.15.1",
+      "X-Goog-Api-Client": "gl-node/22.17.0"
+    },
+    // Qwen OAuth configuration
+    clientId: "f0304373b74a44d2b584a3fb70ca9e56", // From CLIProxyAPI
+    tokenUrl: "https://chat.qwen.ai/api/v1/oauth2/token",
+    authUrl: "https://chat.qwen.ai/api/v1/oauth2/device/code"
+  },
+  iflow: {
+    baseUrl: "https://apis.iflow.cn/v1/chat/completions",
+    format: "openai",
+    headers: {
+      "User-Agent": "iFlow-Cli"
+    },
+    // iFlow OAuth configuration (from CLIProxyAPI)
+    clientId: "10009311001",
+    clientSecret: "4Z3YjXycVsQvyGF1etiNlIBB4RsqSDtW",
+    tokenUrl: "https://iflow.cn/oauth/token",
+    authUrl: "https://iflow.cn/oauth"
+  },
+  antigravity: {
+    baseUrls: [
+      "https://daily-cloudcode-pa.sandbox.googleapis.com",
+      "https://cloudcode-pa.googleapis.com"
+    ],
+    format: "antigravity",
+    headers: {
+      "User-Agent": "antigravity/1.11.5 windows/amd64"
+    },
+    clientId: "1071006060591-tmhssin2h21lcre235vtolojh4g403ep.apps.googleusercontent.com",
+    clientSecret: "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"
+  },
+  openrouter: {
+    baseUrl: "https://openrouter.ai/api/v1/chat/completions",
+    format: "openai",
+    headers: {
+      "HTTP-Referer": "https://endpoint-proxy.local",
+      "X-Title": "Endpoint Proxy"
+    }
+  },
+  openai: {
+    baseUrl: "https://api.openai.com/v1/chat/completions",
+    format: "openai"
+  },
+  glm: {
+    baseUrl: "https://api.z.ai/api/anthropic/v1/messages",
+    format: "claude",
+    headers: {
+      "Anthropic-Version": "2023-06-01",
+      "Anthropic-Beta": "claude-code-20250219,interleaved-thinking-2025-05-14"
+    }
+  },
+  kimi: {
+    baseUrl: "https://api.kimi.com/coding/v1/messages",
+    format: "claude",
+    headers: {
+      "Anthropic-Version": "2023-06-01",
+      "Anthropic-Beta": "claude-code-20250219,interleaved-thinking-2025-05-14"
+    }
+  },
+  minimax: {
+    baseUrl: "https://api.minimax.io/anthropic/v1/messages",
+    format: "claude",
+    headers: {
+      "Anthropic-Version": "2023-06-01",
+      "Anthropic-Beta": "claude-code-20250219,interleaved-thinking-2025-05-14"
+    }
+  },
+  github: {
+    baseUrl: "https://api.githubcopilot.com/chat/completions", // GitHub Copilot API endpoint for chat
+    format: "openai", // GitHub Copilot uses OpenAI-compatible format
+    headers: {
+      "copilot-integration-id": "vscode-chat",
+      "editor-version": "vscode/1.107.1",
+      "editor-plugin-version": "copilot-chat/0.26.7",
+      "user-agent": "GitHubCopilotChat/0.26.7",
+      "openai-intent": "conversation-panel",
+      "x-github-api-version": "2025-04-01",
+      "x-vscode-user-agent-library-version": "electron-fetch",
+      "X-Initiator": "user",
+      "Accept": "application/json",
+      "Content-Type": "application/json"
+    }
+  }
+};
+
+  // Claude system prompt
+  export const CLAUDE_SYSTEM_PROMPT = "You are Claude Code, Anthropic's official CLI for Claude.";
+
+// OAuth endpoints
+export const OAUTH_ENDPOINTS = {
+  google: {
+    token: "https://oauth2.googleapis.com/token",
+    auth: "https://accounts.google.com/o/oauth2/auth"
+  },
+  openai: {
+    token: "https://auth.openai.com/oauth/token",
+    auth: "https://auth.openai.com/oauth/authorize"
+  },
+  anthropic: {
+    token: "https://console.anthropic.com/v1/oauth/token",
+    auth: "https://console.anthropic.com/v1/oauth/authorize"
+  },
+  qwen: {
+    token: "https://chat.qwen.ai/api/v1/oauth2/token", // From CLIProxyAPI
+    auth: "https://chat.qwen.ai/api/v1/oauth2/device/code" // From CLIProxyAPI
+  },
+  iflow: {
+    token: "https://iflow.cn/oauth/token",
+    auth: "https://iflow.cn/oauth"
+  },
+  github: {
+    token: "https://github.com/login/oauth/access_token",
+    auth: "https://github.com/login/oauth/authorize",
+    deviceCode: "https://github.com/login/device/code"
+  }
+};
+
+// Cache TTLs (seconds)
+export const CACHE_TTL = {
+  userInfo: 300,    // 5 minutes
+  modelAlias: 3600  // 1 hour
+};
+
+// Default max tokens
+export const DEFAULT_MAX_TOKENS = 64000;
+
+// Minimum max tokens for tool calling (to prevent truncated arguments)
+export const DEFAULT_MIN_TOKENS = 32000;
+
+// Exponential backoff config for rate limits (like CLIProxyAPI)
+export const BACKOFF_CONFIG = {
+  base: 1000,              // 1 second base
+  max: 30 * 60 * 1000,     // 30 minutes max
+  maxLevel: 15             // Cap backoff level
+};
+
+// Error-based cooldown times (aligned with CLIProxyAPI)
+export const COOLDOWN_MS = {
+  unauthorized: 30 * 60 * 1000,       // 401 → 30 min
+  paymentRequired: 30 * 60 * 1000,    // 402/403 → 30 min
+  notFound: 12 * 60 * 60 * 1000,      // 404 → 12 hours
+  transient: 30 * 1000,               // 408/500/502/503/504 → 1 min
+  requestNotAllowed: 5 * 1000,        // "Request not allowed" → 5 sec
+  // Legacy aliases for backward compatibility
+  rateLimit: 15 * 60 * 1000,
+  serviceUnavailable: 60 * 1000,
+  authExpired: 30 * 60 * 1000
+};
+
+// Skip patterns - requests containing these texts will bypass provider
+export const SKIP_PATTERNS = [
+  "Please write a 5-10 word title for the following conversation:"
+];
+

open-sse/config/defaultThinkingSignature.js

@@ -0,0 +1,7 @@
+// Default signature for thinking mode when no signature from thinkingStore
+export const DEFAULT_THINKING_CLAUDE_SIGNATURE = "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";
+
+export const DEFAULT_THINKING_GEMINI_SIGNATURE = "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";
+
+export const DEFAULT_THINKING_TEXT = "...";
+

open-sse/config/ollamaModels.js

@@ -0,0 +1,19 @@
+export const ollamaModels = {
+  models: [
+    {
+      name: "llama3.2",
+      modified_at: "2025-12-26T00:00:00Z",
+      size: 2000000000,
+      digest: "abc123def456",
+      details: { format: "gguf", family: "llama", parameter_size: "3B", quantization_level: "Q4_K_M" }
+    },
+    {
+      name: "qwen2.5",
+      modified_at: "2025-12-26T00:00:00Z",
+      size: 4000000000,
+      digest: "def456abc123",
+      details: { format: "gguf", family: "qwen", parameter_size: "7B", quantization_level: "Q4_K_M" }
+    }
+  ]
+};
+

open-sse/config/providerModels.js

@@ -0,0 +1,161 @@
+// Provider models - Single source of truth
+// Key = alias (cc, cx, gc, qw, if, ag, gh for OAuth; id for API Key)
+// Field "provider" for special cases (e.g. AntiGravity models that call different backends)
+
+export const PROVIDER_MODELS = {
+  // OAuth Providers (using alias)
+  cc: [  // Claude Code
+    { id: "claude-opus-4-5-20251101", name: "Claude 4.5 Opus" },
+    { id: "claude-sonnet-4-5-20250929", name: "Claude 4.5 Sonnet" },
+    { id: "claude-haiku-4-5-20251001", name: "Claude 4.5 Haiku" },
+  ],
+  cx: [  // OpenAI Codex
+    { id: "gpt-5.2-codex", name: "GPT 5.2 Codex" },
+    { id: "gpt-5.2", name: "GPT 5.2" },
+    { id: "gpt-5.1-codex-max", name: "GPT 5.1 Codex Max" },
+    { id: "gpt-5.1-codex", name: "GPT 5.1 Codex" },
+    { id: "gpt-5.1-codex-mini", name: "GPT 5.1 Codex Mini" },
+    { id: "gpt-5.1", name: "GPT 5.1" },
+    { id: "gpt-5-codex", name: "GPT 5 Codex" },
+    { id: "gpt-5-codex-mini", name: "GPT 5 Codex Mini" },
+  ],
+  gc: [  // Gemini CLI
+    { id: "gemini-3-flash-preview", name: "Gemini 3 Flash Preview" },
+    { id: "gemini-3-pro-preview", name: "Gemini 3 Pro Preview" },
+    { id: "gemini-2.5-pro", name: "Gemini 2.5 Pro" },
+    { id: "gemini-2.5-flash", name: "Gemini 2.5 Flash" },
+    { id: "gemini-2.5-flash-lite", name: "Gemini 2.5 Flash Lite" },
+  ],
+  qw: [  // Qwen Code
+    { id: "qwen3-coder-plus", name: "Qwen3 Coder Plus" },
+    { id: "qwen3-coder-flash", name: "Qwen3 Coder Flash" },
+    { id: "vision-model", name: "Qwen3 Vision Model" },
+  ],
+  if: [  // iFlow AI
+    { id: "qwen3-coder-plus", name: "Qwen3 Coder Plus" },
+    { id: "kimi-k2", name: "Kimi K2" },
+    { id: "kimi-k2-thinking", name: "Kimi K2 Thinking" },
+    { id: "deepseek-r1", name: "DeepSeek R1" },
+    { id: "deepseek-v3.2-chat", name: "DeepSeek V3.2 Chat" },
+    { id: "deepseek-v3.2-reasoner", name: "DeepSeek V3.2 Reasoner" },
+    { id: "minimax-m2", name: "MiniMax M2" },
+    { id: "glm-4.6", name: "GLM 4.6" },
+    { id: "glm-4.7", name: "GLM 4.7" },
+  ],
+  ag: [  // Antigravity - special case: models call different backends
+    { id: "gemini-3-pro-low", name: "Gemini 3 Pro Low" },
+    { id: "gemini-3-pro-high", name: "Gemini 3 Pro High" },
+    { id: "gemini-3-flash", name: "Gemini 3 Flash" },
+    { id: "gemini-2.5-flash", name: "Gemini 2.5 Flash" },
+    { id: "claude-sonnet-4-5", name: "Claude Sonnet 4.5 " },
+    { id: "claude-sonnet-4-5-thinking", name: "Claude Sonnet 4.5 Thinking" },
+    { id: "claude-opus-4-5-thinking", name: "Claude Opus 4.5" },
+  ],
+  gh: [  // GitHub Copilot
+    { id: "gpt-5", name: "GPT-5" },
+    { id: "gpt-5-mini", name: "GPT-5 Mini" },
+    // { id: "gpt-5.1", name: "GPT-5.1" },
+    // { id: "gpt-5.2", name: "GPT-5.2" },
+    // { id: "gpt-5-codex", name: "GPT-5 Codex" },
+    { id: "gpt-5.1-codex", name: "GPT-5.1 Codex" },
+    // { id: "gpt-5.1-codex-mini", name: "GPT-5.1 Codex Mini" },
+    { id: "gpt-5.1-codex-max", name: "GPT-5.1 Codex Max" },
+    { id: "gpt-4.1", name: "GPT-4.1" },
+    { id: "claude-4.5-sonnet", name: "Claude 4.5 Sonnet" },
+    { id: "claude-4.5-opus", name: "Claude 4.5 Opus" },
+    { id: "claude-4.5-haiku", name: "Claude 4.5 Haiku" },
+    { id: "gemini-3-pro", name: "Gemini 3 Pro" },
+    { id: "gemini-3-flash", name: "Gemini 3 Flash" },
+    { id: "gemini-2.5-pro", name: "Gemini 2.5 Pro" },
+    { id: "grok-code-fast-1", name: "Grok Code Fast 1" },
+  ],
+
+  // API Key Providers (alias = id)
+  openai: [
+    { id: "gpt-4o", name: "GPT-4o" },
+    { id: "gpt-4o-mini", name: "GPT-4o Mini" },
+    { id: "gpt-4-turbo", name: "GPT-4 Turbo" },
+    { id: "o1", name: "O1" },
+    { id: "o1-mini", name: "O1 Mini" },
+  ],
+  anthropic: [
+    { id: "claude-sonnet-4-20250514", name: "Claude Sonnet 4" },
+    { id: "claude-opus-4-20250514", name: "Claude Opus 4" },
+    { id: "claude-3-5-sonnet-20241022", name: "Claude 3.5 Sonnet" },
+  ],
+  gemini: [
+    { id: "gemini-3-pro-preview", name: "Gemini 3 Pro Preview" },
+    { id: "gemini-2.5-pro", name: "Gemini 2.5 Pro" },
+    { id: "gemini-2.5-flash", name: "Gemini 2.5 Flash" },
+    { id: "gemini-2.5-flash-lite", name: "Gemini 2.5 Flash Lite" },
+  ],
+  openrouter: [
+    { id: "auto", name: "Auto (Best Available)" },
+  ],
+  glm: [
+    { id: "glm-4.7", name: "GLM 4.7" },
+    { id: "glm-4.6", name: "GLM 4.6" },
+    { id: "glm-4.6v", name: "GLM 4.6V (Vision)" },
+  ],
+  kimi: [
+    { id: "kimi-latest", name: "Kimi Latest" },
+  ],
+  minimax: [
+    { id: "MiniMax-M2.1", name: "MiniMax M2.1" },
+  ],
+};
+
+// Helper functions
+export function getProviderModels(aliasOrId) {
+  return PROVIDER_MODELS[aliasOrId] || [];
+}
+
+export function getDefaultModel(aliasOrId) {
+  const models = PROVIDER_MODELS[aliasOrId];
+  return models?.[0]?.id || null;
+}
+
+export function isValidModel(aliasOrId, modelId, passthroughProviders = new Set()) {
+  if (passthroughProviders.has(aliasOrId)) return true;
+  const models = PROVIDER_MODELS[aliasOrId];
+  if (!models) return false;
+  return models.some(m => m.id === modelId);
+}
+
+export function findModelName(aliasOrId, modelId) {
+  const models = PROVIDER_MODELS[aliasOrId];
+  if (!models) return modelId;
+  const found = models.find(m => m.id === modelId);
+  return found?.name || modelId;
+}
+
+export function getModelTargetFormat(aliasOrId, modelId) {
+  const models = PROVIDER_MODELS[aliasOrId];
+  if (!models) return null;
+  const found = models.find(m => m.id === modelId);
+  return found?.targetFormat || null;
+}
+
+// Provider ID to alias mapping
+export const PROVIDER_ID_TO_ALIAS = {
+  claude: "cc",
+  codex: "cx",
+  "gemini-cli": "gc",
+  qwen: "qw",
+  iflow: "if",
+  antigravity: "ag",
+  github: "gh",
+  openai: "openai",
+  anthropic: "anthropic",
+  gemini: "gemini",
+  openrouter: "openrouter",
+  glm: "glm",
+  kimi: "kimi",
+  minimax: "minimax",
+};
+
+export function getModelsByProviderId(providerId) {
+  const alias = PROVIDER_ID_TO_ALIAS[providerId] || providerId;
+  return PROVIDER_MODELS[alias] || [];
+}
+

open-sse/handlers/chatCore.js

@@ -0,0 +1,277 @@
+import { detectFormat, getTargetFormat, buildProviderUrl, buildProviderHeaders } from "../services/provider.js";
+import { translateRequest, needsTranslation } from "../translator/index.js";
+import { FORMATS } from "../translator/formats.js";
+import { createSSETransformStreamWithLogger, createPassthroughStreamWithLogger, COLORS } from "../utils/stream.js";
+import { createStreamController, pipeWithDisconnect } from "../utils/streamHandler.js";
+import { refreshTokenByProvider, refreshWithRetry } from "../services/tokenRefresh.js";
+import { createRequestLogger } from "../utils/requestLogger.js";
+import { getModelTargetFormat, PROVIDER_ID_TO_ALIAS } from "../config/providerModels.js";
+import { createErrorResult, parseUpstreamError, formatProviderError } from "../utils/error.js";
+import { handleBypassRequest } from "../utils/bypassHandler.js";
+
+/**
+ * Core chat handler - shared between SSE and Worker
+ * Returns { success, response, status, error } for caller to handle fallback
+ * @param {object} options
+ * @param {object} options.body - Request body
+ * @param {object} options.modelInfo - { provider, model }
+ * @param {object} options.credentials - Provider credentials
+ * @param {object} options.log - Logger instance (optional)
+ * @param {function} options.onCredentialsRefreshed - Callback when credentials are refreshed
+ * @param {function} options.onRequestSuccess - Callback when request succeeds (to clear error status)
+ * @param {function} options.onDisconnect - Callback when client disconnects
+ */
+export async function handleChatCore({ body, modelInfo, credentials, log, onCredentialsRefreshed, onRequestSuccess, onDisconnect, clientRawRequest }) {
+  const { provider, model } = modelInfo;
+
+  const sourceFormat = detectFormat(body);
+
+  // Check for bypass patterns (warmup, skip) - return fake response
+  const bypassResponse = handleBypassRequest(body, model);
+  if (bypassResponse) {
+    return bypassResponse;
+  }
+
+  // Detect source format and get target format
+  // Model-specific targetFormat takes priority over provider default
+
+  const alias = PROVIDER_ID_TO_ALIAS[provider] || provider;
+  const modelTargetFormat = getModelTargetFormat(alias, model);
+  const targetFormat = modelTargetFormat || getTargetFormat(provider);
+  const stream = body.stream !== false;
+
+  // Create request logger for this session: sourceFormat_targetFormat_model
+  const reqLogger = await createRequestLogger(sourceFormat, targetFormat, model);
+  
+  // 0. Log client raw request (before any conversion)
+  if (clientRawRequest) {
+    reqLogger.logClientRawRequest(
+      clientRawRequest.endpoint,
+      clientRawRequest.body,
+      clientRawRequest.headers
+    );
+  }
+  
+  // 1. Log raw request from client
+  reqLogger.logRawRequest(body);
+  
+  // 1a. Log format detection info
+  reqLogger.logFormatInfo({
+    sourceFormat,
+    targetFormat,
+    provider,
+    model,
+    stream
+  });
+
+  log?.debug?.("FORMAT", `${sourceFormat} → ${targetFormat} | stream=${stream}`);
+
+  // Translate request
+  let translatedBody = body;
+  translatedBody = translateRequest(sourceFormat, targetFormat, model, body, stream, credentials, provider);
+  
+
+  // Update model in body
+  translatedBody.model = model;
+
+  // Build provider URL and headers
+  const providerUrl = buildProviderUrl(provider, model, stream);
+  const providerHeaders = buildProviderHeaders(provider, credentials, stream, translatedBody);
+
+  // 2. Log converted request to provider
+  reqLogger.logConvertedRequest(providerUrl, providerHeaders, translatedBody);
+
+  const msgCount = translatedBody.messages?.length 
+    || translatedBody.contents?.length 
+    || translatedBody.request?.contents?.length 
+    || 0;
+  log?.debug?.("REQUEST", `${provider.toUpperCase()} | ${model} | ${msgCount} msgs`);
+  
+  // Log headers (mask sensitive values)
+  const safeHeaders = {};
+  for (const [key, value] of Object.entries(providerHeaders)) {
+    if (key.toLowerCase().includes("auth") || key.toLowerCase().includes("key") || key.toLowerCase().includes("token")) {
+      safeHeaders[key] = value ? `${value.slice(0, 10)}...` : "";
+    } else {
+      safeHeaders[key] = value;
+    }
+  }
+  log?.debug?.("HEADERS", JSON.stringify(safeHeaders));
+
+  // Create stream controller for disconnect detection
+  const streamController = createStreamController({ onDisconnect, log, provider, model });
+
+  // Make request to provider with abort signal
+  let providerResponse;
+  try {
+    providerResponse = await fetch(providerUrl, {
+      method: "POST",
+      headers: providerHeaders,
+      body: JSON.stringify(translatedBody),
+      signal: streamController.signal
+    });
+  } catch (error) {
+    if (error.name === "AbortError") {
+      streamController.handleError(error);
+      return createErrorResult(499, "Request aborted");
+    }
+    const errMsg = formatProviderError(error, provider, model);
+    console.log(`${COLORS.red}[ERROR] ${errMsg}${COLORS.reset}`);
+    return createErrorResult(502, errMsg);
+  }
+
+
+  // Handle 401/403 - try token refresh
+  if (providerResponse.status === 401 || providerResponse.status === 403) {
+    let newCredentials = null;
+    
+    // GitHub needs special handling - refresh copilotToken using accessToken
+    if (provider === "github") {
+      const { refreshCopilotToken, refreshGitHubToken } = await import("../services/tokenRefresh.js");
+      
+      // First try refreshing copilotToken using existing accessToken
+      let copilotResult = await refreshCopilotToken(credentials.accessToken, log);
+      
+      // If that fails, refresh GitHub accessToken first, then get new copilotToken
+      if (!copilotResult && credentials.refreshToken) {
+        const githubTokens = await refreshGitHubToken(credentials.refreshToken, log);
+        if (githubTokens?.accessToken) {
+          credentials.accessToken = githubTokens.accessToken;
+          if (githubTokens.refreshToken) {
+            credentials.refreshToken = githubTokens.refreshToken;
+          }
+          copilotResult = await refreshCopilotToken(githubTokens.accessToken, log);
+        }
+      }
+      
+      if (copilotResult?.token) {
+        credentials.copilotToken = copilotResult.token;
+        newCredentials = {
+          accessToken: credentials.accessToken,
+          refreshToken: credentials.refreshToken,
+          providerSpecificData: {
+            ...credentials.providerSpecificData,
+            copilotToken: copilotResult.token,
+            copilotTokenExpiresAt: copilotResult.expiresAt
+          }
+        };
+        log?.info?.("TOKEN", `${provider.toUpperCase()} | copilotToken refreshed`);
+      }
+    } else {
+      newCredentials = await refreshWithRetry(
+        () => refreshTokenByProvider(provider, credentials, log),
+        3,
+        log
+      );
+    }
+
+    if (newCredentials?.accessToken || (provider === "github" && credentials.copilotToken)) {
+      if (newCredentials?.accessToken) {
+        log?.info?.("TOKEN", `${provider.toUpperCase()} | refreshed`);
+        credentials.accessToken = newCredentials.accessToken;
+      }
+      if (newCredentials?.refreshToken) {
+        credentials.refreshToken = newCredentials.refreshToken;
+      }
+      if (newCredentials?.providerSpecificData) {
+        credentials.providerSpecificData = {
+          ...credentials.providerSpecificData,
+          ...newCredentials.providerSpecificData
+        };
+      }
+
+      // Notify caller about refreshed credentials
+      if (onCredentialsRefreshed && newCredentials) {
+        await onCredentialsRefreshed(newCredentials);
+      }
+
+      // Retry with new credentials
+      const newHeaders = buildProviderHeaders(provider, credentials, stream, translatedBody);
+      const retryResponse = await fetch(providerUrl, {
+        method: "POST",
+        headers: newHeaders,
+        body: JSON.stringify(translatedBody),
+        signal: streamController.signal
+      });
+
+      if (retryResponse.ok) {
+        providerResponse = retryResponse;
+      }
+    } else {
+      log?.warn?.("TOKEN", `${provider.toUpperCase()} | refresh failed`);
+    }
+  }
+
+  // Check provider response - return error info for fallback handling
+  if (!providerResponse.ok) {
+    const { statusCode, message } = await parseUpstreamError(providerResponse);
+    const errMsg = formatProviderError(new Error(message), provider, model);
+    console.log(`${COLORS.red}[ERROR] ${errMsg}${COLORS.reset}`);
+    
+    // Log error with full request body for debugging
+    reqLogger.logError(new Error(message), translatedBody);
+
+    return createErrorResult(statusCode, errMsg);
+  }
+
+  // Non-streaming response
+  if (!stream) {
+    const responseBody = await providerResponse.json();
+    
+    // Notify success - caller can clear error status if needed
+    if (onRequestSuccess) {
+      await onRequestSuccess();
+    }
+    
+    return {
+      success: true,
+      response: new Response(JSON.stringify(responseBody), {
+        headers: {
+          "Content-Type": "application/json",
+          "Access-Control-Allow-Origin": "*"
+        }
+      })
+    };
+  }
+
+  // Streaming response
+  
+  // Notify success - caller can clear error status if needed
+  if (onRequestSuccess) {
+    await onRequestSuccess();
+  }
+
+  const responseHeaders = {
+    "Content-Type": "text/event-stream",
+    "Cache-Control": "no-cache",
+    "Connection": "keep-alive",
+    "Access-Control-Allow-Origin": "*"
+  };
+
+  // Create transform stream with logger for streaming response
+  let transformStream;
+  if (needsTranslation(targetFormat, sourceFormat)) {
+    transformStream = createSSETransformStreamWithLogger(targetFormat, sourceFormat, provider, reqLogger);
+  } else {
+    transformStream = createPassthroughStreamWithLogger(provider, reqLogger);
+  }
+
+  // Pipe response through transform with disconnect detection
+  const transformedBody = pipeWithDisconnect(providerResponse, transformStream, streamController);
+
+  return {
+    success: true,
+    response: new Response(transformedBody, {
+      headers: responseHeaders
+    })
+  };
+}
+
+/**
+ * Check if token is expired or about to expire
+ */
+export function isTokenExpiringSoon(expiresAt, bufferMs = 5 * 60 * 1000) {
+  if (!expiresAt) return false;
+  const expiresAtMs = new Date(expiresAt).getTime();
+  return expiresAtMs - Date.now() < bufferMs;
+}

open-sse/handlers/responsesHandler.js

@@ -0,0 +1,69 @@
+/**
+ * Responses API Handler for Workers
+ * Converts Chat Completions to Codex Responses API format
+ */
+
+import { handleChatCore } from "./chatCore.js";
+import { convertResponsesApiFormat } from "../translator/helpers/responsesApiHelper.js";
+import { createResponsesApiTransformStream } from "../transformer/responsesTransformer.js";
+
+/**
+ * Handle /v1/responses request
+ * @param {object} options
+ * @param {object} options.body - Request body (Responses API format)
+ * @param {object} options.modelInfo - { provider, model }
+ * @param {object} options.credentials - Provider credentials
+ * @param {object} options.log - Logger instance (optional)
+ * @param {function} options.onCredentialsRefreshed - Callback when credentials are refreshed
+ * @param {function} options.onRequestSuccess - Callback when request succeeds
+ * @param {function} options.onDisconnect - Callback when client disconnects
+ * @returns {Promise<{success: boolean, response?: Response, status?: number, error?: string}>}
+ */
+export async function handleResponsesCore({ body, modelInfo, credentials, log, onCredentialsRefreshed, onRequestSuccess, onDisconnect }) {
+  // Convert Responses API format to Chat Completions format
+  const convertedBody = convertResponsesApiFormat(body);
+  
+  // Ensure stream is enabled
+  convertedBody.stream = true;
+
+  // Call chat core handler
+  const result = await handleChatCore({
+    body: convertedBody,
+    modelInfo,
+    credentials,
+    log,
+    onCredentialsRefreshed,
+    onRequestSuccess,
+    onDisconnect
+  });
+
+  if (!result.success || !result.response) {
+    return result;
+  }
+
+  const response = result.response;
+  const contentType = response.headers.get("Content-Type") || "";
+
+  // If not SSE or error, return as-is
+  if (!contentType.includes("text/event-stream") || response.status !== 200) {
+    return result;
+  }
+
+  // Transform SSE stream to Responses API format (no logging in worker)
+  const transformStream = createResponsesApiTransformStream(null);
+  const transformedBody = response.body.pipeThrough(transformStream);
+
+  return {
+    success: true,
+    response: new Response(transformedBody, {
+      status: 200,
+      headers: {
+        "Content-Type": "text/event-stream",
+        "Cache-Control": "no-cache",
+        "Connection": "keep-alive",
+        "Access-Control-Allow-Origin": "*"
+      }
+    })
+  };
+}
+

open-sse/index.js

@@ -0,0 +1,66 @@
+// Config
+export { PROVIDERS, OAUTH_ENDPOINTS, CACHE_TTL, DEFAULT_MAX_TOKENS, CLAUDE_SYSTEM_PROMPT, COOLDOWN_MS, BACKOFF_CONFIG } from "./config/constants.js";
+export { 
+  PROVIDER_MODELS, 
+  getProviderModels,
+  getDefaultModel, 
+  isValidModel,
+  findModelName,
+  getModelTargetFormat,
+  PROVIDER_ID_TO_ALIAS,
+  getModelsByProviderId
+} from "./config/providerModels.js";
+
+// Translator
+export { FORMATS } from "./translator/formats.js";
+export { 
+  register, 
+  translateRequest, 
+  translateResponse, 
+  needsTranslation, 
+  initState, 
+  initTranslators 
+} from "./translator/index.js";
+
+// Services
+export { 
+  detectFormat, 
+  getProviderConfig, 
+  buildProviderUrl, 
+  buildProviderHeaders, 
+  getTargetFormat 
+} from "./services/provider.js";
+
+export { parseModel, resolveModelAliasFromMap, getModelInfoCore } from "./services/model.js";
+
+export {
+  checkFallbackError,
+  isAccountUnavailable,
+  getUnavailableUntil,
+  filterAvailableAccounts
+} from "./services/accountFallback.js";
+
+export {
+  TOKEN_EXPIRY_BUFFER_MS,
+  refreshAccessToken,
+  refreshClaudeOAuthToken,
+  refreshGoogleToken,
+  refreshQwenToken,
+  refreshCodexToken,
+  refreshIflowToken,
+  refreshGitHubToken,
+  refreshCopilotToken,
+  getAccessToken,
+  refreshTokenByProvider
+} from "./services/tokenRefresh.js";
+
+// Handlers
+export { handleChatCore, isTokenExpiringSoon } from "./handlers/chatCore.js";
+export { createStreamController, pipeWithDisconnect, createDisconnectAwareStream } from "./utils/streamHandler.js";
+
+// Utils
+export { errorResponse, formatProviderError } from "./utils/error.js";
+export { 
+  createSSETransformStreamWithLogger, 
+  createPassthroughStreamWithLogger 
+} from "./utils/stream.js";

open-sse/services/accountFallback.js

@@ -0,0 +1,148 @@
+import { COOLDOWN_MS, BACKOFF_CONFIG } from "../config/constants.js";
+
+/**
+ * Calculate exponential backoff cooldown for rate limits (429)
+ * Level 0: 1s, Level 1: 2s, Level 2: 4s... → max 30 min
+ * @param {number} backoffLevel - Current backoff level
+ * @returns {number} Cooldown in milliseconds
+ */
+export function getQuotaCooldown(backoffLevel = 0) {
+  const cooldown = BACKOFF_CONFIG.base * Math.pow(2, backoffLevel);
+  return Math.min(cooldown, BACKOFF_CONFIG.max);
+}
+
+/**
+ * Check if error should trigger account fallback (switch to next account)
+ * @param {number} status - HTTP status code
+ * @param {string} errorText - Error message text
+ * @param {number} backoffLevel - Current backoff level for exponential backoff
+ * @returns {{ shouldFallback: boolean, cooldownMs: number, newBackoffLevel?: number }}
+ */
+export function checkFallbackError(status, errorText, backoffLevel = 0) {
+  // Check error message FIRST - specific patterns take priority over status codes
+  if (errorText) {
+    const lowerError = errorText.toLowerCase();
+    
+    // "Request not allowed" - short cooldown (5s), takes priority over status code
+    if (lowerError.includes("request not allowed")) {
+      return { shouldFallback: true, cooldownMs: COOLDOWN_MS.requestNotAllowed };
+    }
+    
+    // Rate limit keywords - exponential backoff
+    if (
+      lowerError.includes("rate limit") ||
+      lowerError.includes("too many requests") ||
+      lowerError.includes("quota exceeded") ||
+      lowerError.includes("capacity") ||
+      lowerError.includes("overloaded")
+    ) {
+      const newLevel = Math.min(backoffLevel + 1, BACKOFF_CONFIG.maxLevel);
+      return { 
+        shouldFallback: true, 
+        cooldownMs: getQuotaCooldown(backoffLevel),
+        newBackoffLevel: newLevel
+      };
+    }
+  }
+
+  // 401 - Authentication error (token expired/invalid)
+  if (status === 401) {
+    return { shouldFallback: true, cooldownMs: COOLDOWN_MS.unauthorized };
+  }
+
+  // 402/403 - Payment required / Forbidden (quota/permission)
+  if (status === 402 || status === 403) {
+    return { shouldFallback: true, cooldownMs: COOLDOWN_MS.paymentRequired };
+  }
+
+  // 404 - Model not found (long cooldown)
+  if (status === 404) {
+    return { shouldFallback: true, cooldownMs: COOLDOWN_MS.notFound };
+  }
+
+  // 429 - Rate limit with exponential backoff
+  if (status === 429) {
+    const newLevel = Math.min(backoffLevel + 1, BACKOFF_CONFIG.maxLevel);
+    return { 
+      shouldFallback: true, 
+      cooldownMs: getQuotaCooldown(backoffLevel),
+      newBackoffLevel: newLevel
+    };
+  }
+
+  // 408/500/502/503/504 - Transient errors (short cooldown)
+  if (status === 408 || status === 500 || status === 502 || status === 503 || status === 504) {
+    return { shouldFallback: true, cooldownMs: COOLDOWN_MS.transient };
+  }
+
+  return { shouldFallback: false, cooldownMs: 0 };
+}
+
+/**
+ * Check if account is currently unavailable (cooldown not expired)
+ */
+export function isAccountUnavailable(unavailableUntil) {
+  if (!unavailableUntil) return false;
+  return new Date(unavailableUntil).getTime() > Date.now();
+}
+
+/**
+ * Calculate unavailable until timestamp
+ */
+export function getUnavailableUntil(cooldownMs) {
+  return new Date(Date.now() + cooldownMs).toISOString();
+}
+
+/**
+ * Filter available accounts (not in cooldown)
+ */
+export function filterAvailableAccounts(accounts, excludeId = null) {
+  const now = Date.now();
+  return accounts.filter(acc => {
+    if (excludeId && acc.id === excludeId) return false;
+    if (acc.rateLimitedUntil) {
+      const until = new Date(acc.rateLimitedUntil).getTime();
+      if (until > now) return false;
+    }
+    return true;
+  });
+}
+
+/**
+ * Reset account state when request succeeds
+ * Clears cooldown and resets backoff level to 0
+ * @param {object} account - Account object
+ * @returns {object} Updated account with reset state
+ */
+export function resetAccountState(account) {
+  if (!account) return account;
+  return {
+    ...account,
+    rateLimitedUntil: null,
+    backoffLevel: 0,
+    lastError: null,
+    status: "active"
+  };
+}
+
+/**
+ * Apply error state to account
+ * @param {object} account - Account object
+ * @param {number} status - HTTP status code
+ * @param {string} errorText - Error message
+ * @returns {object} Updated account with error state
+ */
+export function applyErrorState(account, status, errorText) {
+  if (!account) return account;
+  
+  const backoffLevel = account.backoffLevel || 0;
+  const { cooldownMs, newBackoffLevel } = checkFallbackError(status, errorText, backoffLevel);
+  
+  return {
+    ...account,
+    rateLimitedUntil: cooldownMs > 0 ? getUnavailableUntil(cooldownMs) : null,
+    backoffLevel: newBackoffLevel ?? backoffLevel,
+    lastError: { status, message: errorText, timestamp: new Date().toISOString() },
+    status: "error"
+  };
+}

open-sse/services/combo.js

@@ -0,0 +1,69 @@
+/**
+ * Shared combo (model combo) handling with fallback support
+ */
+
+/**
+ * Get combo models from combos data
+ * @param {string} modelStr - Model string to check
+ * @param {Array|Object} combosData - Array of combos or object with combos
+ * @returns {string[]|null} Array of models or null if not a combo
+ */
+export function getComboModelsFromData(modelStr, combosData) {
+  // Don't check if it's in provider/model format
+  if (modelStr.includes("/")) return null;
+  
+  // Handle both array and object formats
+  const combos = Array.isArray(combosData) ? combosData : (combosData?.combos || []);
+  
+  const combo = combos.find(c => c.name === modelStr);
+  if (combo && combo.models && combo.models.length > 0) {
+    return combo.models;
+  }
+  return null;
+}
+
+/**
+ * Handle combo chat with fallback
+ * @param {Object} options
+ * @param {Object} options.body - Request body
+ * @param {string[]} options.models - Array of model strings to try
+ * @param {Function} options.handleSingleModel - Function to handle single model: (body, modelStr) => Promise<Response>
+ * @param {Object} options.log - Logger object
+ * @returns {Promise<Response>}
+ */
+export async function handleComboChat({ body, models, handleSingleModel, log }) {
+  let lastError = null;
+
+  for (let i = 0; i < models.length; i++) {
+    const modelStr = models[i];
+    log.info("COMBO", `Trying model ${i + 1}/${models.length}: ${modelStr}`);
+
+    const result = await handleSingleModel(body, modelStr);
+    
+    // Success (2xx) - return response
+    if (result.ok) {
+      return result;
+    }
+
+    // 401 unauthorized - return immediately (auth error)
+    if (result.status === 401) {
+      return result;
+    }
+
+    // 4xx/5xx - try next model
+    lastError = `${modelStr}: ${result.statusText || result.status}`;
+    log.warn("COMBO", `Model failed, trying next`, { model: modelStr, status: result.status });
+  }
+
+  log.warn("COMBO", "All models failed");
+  
+  // Return 503 with last error
+  return new Response(
+    JSON.stringify({ error: lastError || "All combo models unavailable" }),
+    { 
+      status: 503, 
+      headers: { "Content-Type": "application/json" }
+    }
+  );
+}
+

open-sse/services/compact.js

@@ -0,0 +1,64 @@
+/**
+ * Shared combo (model combo) handling with fallback support
+ */
+
+/**
+ * Get combo models from combos data
+ * @param {string} modelStr - Model string to check
+ * @param {Array|Object} combosData - Array of combos or object with combos
+ * @returns {string[]|null} Array of models or null if not a combo
+ */
+export function getComboModelsFromData(modelStr, combosData) {
+  // Don't check if it's in provider/model format
+  if (modelStr.includes("/")) return null;
+  
+  // Handle both array and object formats
+  const combos = Array.isArray(combosData) ? combosData : (combosData?.combos || []);
+  
+  const combo = combos.find(c => c.name === modelStr);
+  if (combo && combo.models && combo.models.length > 0) {
+    return combo.models;
+  }
+  return null;
+}
+
+/**
+ * Handle combo chat with fallback
+ * @param {Object} options
+ * @param {Object} options.body - Request body
+ * @param {string[]} options.models - Array of model strings to try
+ * @param {Function} options.handleSingleModel - Function to handle single model: (body, modelStr) => Promise<Response>
+ * @param {Object} options.log - Logger object
+ * @returns {Promise<Response>}
+ */
+export async function handleComboChat({ body, models, handleSingleModel, log }) {
+  let lastError = null;
+
+  for (let i = 0; i < models.length; i++) {
+    const modelStr = models[i];
+    log.info("COMBO", `Trying model ${i + 1}/${models.length}: ${modelStr}`);
+
+    const result = await handleSingleModel(body, modelStr);
+    
+    // Success or client error - return response
+    if (result.ok || result.status < 500) {
+      return result;
+    }
+
+    // 5xx error - try next model
+    lastError = `${modelStr}: ${result.statusText || result.status}`;
+    log.warn("COMBO", `Model failed, trying next`, { model: modelStr, status: result.status });
+  }
+
+  log.warn("COMBO", "All models failed");
+  
+  // Return 503 with last error
+  return new Response(
+    JSON.stringify({ error: lastError || "All combo models unavailable" }),
+    { 
+      status: 503, 
+      headers: { "Content-Type": "application/json" }
+    }
+  );
+}
+

open-sse/services/model.js

@@ -0,0 +1,109 @@
+// Provider alias to ID mapping
+const ALIAS_TO_PROVIDER_ID = {
+  cc: "claude",
+  cx: "codex",
+  gc: "gemini-cli",
+  qw: "qwen",
+  if: "iflow",
+  ag: "antigravity",
+  gh: "github",
+  // API Key providers (alias = id)
+  openai: "openai",
+  anthropic: "anthropic",
+  gemini: "gemini",
+  openrouter: "openrouter",
+};
+
+/**
+ * Resolve provider alias to provider ID
+ */
+export function resolveProviderAlias(aliasOrId) {
+  return ALIAS_TO_PROVIDER_ID[aliasOrId] || aliasOrId;
+}
+
+/**
+ * Parse model string: "alias/model" or "provider/model" or just alias
+ */
+export function parseModel(modelStr) {
+  if (!modelStr) {
+    return { provider: null, model: null, isAlias: false, providerAlias: null };
+  }
+
+  // Check if standard format: provider/model or alias/model
+  if (modelStr.includes("/")) {
+    const firstSlash = modelStr.indexOf("/");
+    const providerOrAlias = modelStr.slice(0, firstSlash);
+    const model = modelStr.slice(firstSlash + 1);
+    const provider = resolveProviderAlias(providerOrAlias);
+    return { provider, model, isAlias: false, providerAlias: providerOrAlias };
+  }
+
+  // Alias format (model alias, not provider alias)
+  return { provider: null, model: modelStr, isAlias: true, providerAlias: null };
+}
+
+/**
+ * Resolve model alias from aliases object
+ * Format: { "alias": "provider/model" }
+ */
+export function resolveModelAliasFromMap(alias, aliases) {
+  if (!aliases) return null;
+  
+  // Check if alias exists
+  const resolved = aliases[alias];
+  if (!resolved) return null;
+  
+  // Resolved value is "provider/model" format
+  if (typeof resolved === "string" && resolved.includes("/")) {
+    const firstSlash = resolved.indexOf("/");
+    const providerOrAlias = resolved.slice(0, firstSlash);
+    return {
+      provider: resolveProviderAlias(providerOrAlias),
+      model: resolved.slice(firstSlash + 1)
+    };
+  }
+  
+  // Or object { provider, model }
+  if (typeof resolved === "object" && resolved.provider && resolved.model) {
+    return {
+      provider: resolveProviderAlias(resolved.provider),
+      model: resolved.model
+    };
+  }
+  
+  return null;
+}
+
+/**
+ * Get full model info (parse or resolve)
+ * @param {string} modelStr - Model string
+ * @param {object|function} aliasesOrGetter - Aliases object or async function to get aliases
+ */
+export async function getModelInfoCore(modelStr, aliasesOrGetter) {
+  const parsed = parseModel(modelStr);
+
+  if (!parsed.isAlias) {
+    return {
+      provider: parsed.provider,
+      model: parsed.model
+    };
+  }
+
+  // Get aliases (from object or function)
+  const aliases = typeof aliasesOrGetter === "function" 
+    ? await aliasesOrGetter() 
+    : aliasesOrGetter;
+
+  // Resolve alias
+  const resolved = resolveModelAliasFromMap(parsed.model, aliases);
+  if (resolved) {
+    return resolved;
+  }
+
+  // Fallback: treat as openai model
+  return {
+    provider: "openai",
+    model: parsed.model
+  };
+}
+

open-sse/services/provider.js

@@ -0,0 +1,237 @@
+import { PROVIDERS } from "../config/constants.js";
+
+// Detect request format from body structure
+export function detectFormat(body) {
+  // OpenAI Responses API: has input[] array instead of messages[]
+  if (body.input && Array.isArray(body.input)) {
+    return "openai-responses";
+  }
+
+  // Gemini format: has contents array
+  if (body.contents && Array.isArray(body.contents)) {
+    return "gemini";
+  }
+
+  // OpenAI-specific indicators (check BEFORE Claude)
+  // These fields are OpenAI-specific and never appear in Claude format
+  if (
+    body.stream_options ||           // OpenAI streaming options
+    body.response_format ||           // JSON mode, etc.
+    body.logprobs !== undefined ||    // Log probabilities
+    body.top_logprobs !== undefined ||
+    body.n !== undefined ||           // Number of completions
+    body.presence_penalty !== undefined ||  // Penalties
+    body.frequency_penalty !== undefined ||
+    body.logit_bias ||                // Token biasing
+    body.user                         // User identifier
+  ) {
+    return "openai";
+  }
+
+  // Claude format: messages with content as array of objects with type
+  // Claude requires content to be array with specific structure
+  if (body.messages && Array.isArray(body.messages)) {
+    const firstMsg = body.messages[0];
+    
+    // If content is array, check if it follows Claude structure
+    if (firstMsg?.content && Array.isArray(firstMsg.content)) {
+      const firstContent = firstMsg.content[0];
+      
+      // Claude format has specific types: text, image, tool_use, tool_result
+      // OpenAI multimodal has: text, image_url (note the difference)
+      if (firstContent?.type === "text" && !body.model?.includes("/")) {
+        // Could be Claude or OpenAI multimodal
+        // Check for Claude-specific fields
+        if (body.system || body.anthropic_version) {
+          return "claude";
+        }
+        // Check if image format is Claude (source.type) vs OpenAI (image_url.url)
+        const hasClaudeImage = firstMsg.content.some(c => 
+          c.type === "image" && c.source?.type === "base64"
+        );
+        const hasOpenAIImage = firstMsg.content.some(c => 
+          c.type === "image_url" && c.image_url?.url
+        );
+        if (hasClaudeImage) return "claude";
+        if (hasOpenAIImage) return "openai";
+        
+        // If still unclear, check for tool format
+        const hasClaudeTool = firstMsg.content.some(c => 
+          c.type === "tool_use" || c.type === "tool_result"
+        );
+        if (hasClaudeTool) return "claude";
+      }
+    }
+    
+    // If content is string, it's likely OpenAI (Claude also supports this)
+    // Check for other Claude-specific indicators
+    if (body.system !== undefined || body.anthropic_version) {
+      return "claude";
+    }
+  }
+
+  // Default to OpenAI format
+  return "openai";
+}
+
+// Get provider config
+export function getProviderConfig(provider) {
+  return PROVIDERS[provider] || PROVIDERS.openai;
+}
+
+// Build provider URL
+export function buildProviderUrl(provider, model, stream = true) {
+  const config = getProviderConfig(provider);
+
+  switch (provider) {
+    case "claude":
+      return `${config.baseUrl}?beta=true`;
+
+    case "gemini": {
+      const action = stream ? "streamGenerateContent?alt=sse" : "generateContent";
+      return `${config.baseUrl}/${model}:${action}`;
+    }
+
+    case "gemini-cli": {
+      const action = stream ? "streamGenerateContent?alt=sse" : "generateContent";
+      return `${config.baseUrl}:${action}`;
+    }
+
+    case "antigravity": {
+      const baseUrl = config.baseUrls[0];
+      const path = stream ? "/v1internal:streamGenerateContent?alt=sse" : "/v1internal:generateContent";
+      return `${baseUrl}${path}`;
+    }
+
+    case "codex":
+      return config.baseUrl;
+
+    case "github":
+      return config.baseUrl;
+
+    case "glm":
+    case "kimi":
+    case "minimax":
+      // Claude-compatible providers
+      return `${config.baseUrl}?beta=true`;
+
+    default:
+      return config.baseUrl;
+  }
+}
+
+// Build provider headers
+export function buildProviderHeaders(provider, credentials, stream = true, body = null) {
+  const config = getProviderConfig(provider);
+  const headers = {
+    "Content-Type": "application/json",
+    ...config.headers
+  };
+
+  // Add auth header
+  switch (provider) {
+    case "gemini":
+      if (credentials.apiKey) {
+        headers["x-goog-api-key"] = credentials.apiKey;
+      } else if (credentials.accessToken) {
+        headers["Authorization"] = `Bearer ${credentials.accessToken}`;
+      }
+      break;
+
+    case "antigravity":
+    case "gemini-cli":
+      // Antigravity and Gemini CLI use OAuth access token
+      headers["Authorization"] = `Bearer ${credentials.accessToken}`;
+      break;
+
+    case "claude":
+      // Claude uses x-api-key header for API key, or Authorization for OAuth
+      if (credentials.apiKey) {
+        headers["x-api-key"] = credentials.apiKey;
+      } else if (credentials.accessToken) {
+        headers["Authorization"] = `Bearer ${credentials.accessToken}`;
+      }
+      break;
+
+    case "github":
+      // GitHub Copilot requires special headers to mimic VSCode
+      // Prioritize copilotToken from providerSpecificData, fallback to accessToken
+      const githubToken = credentials.copilotToken || credentials.accessToken;
+      // Add headers in exact same order as test endpoint
+      headers["Authorization"] = `Bearer ${githubToken}`;
+      headers["Content-Type"] = "application/json";
+      headers["copilot-integration-id"] = "vscode-chat";
+      headers["editor-version"] = "vscode/1.107.1";
+      headers["editor-plugin-version"] = "copilot-chat/0.26.7";
+      headers["user-agent"] = "GitHubCopilotChat/0.26.7";
+      headers["openai-intent"] = "conversation-panel";
+      headers["x-github-api-version"] = "2025-04-01";
+      // Generate a UUID for x-request-id (Cloudflare Workers compatible)
+      headers["x-request-id"] = crypto.randomUUID ? crypto.randomUUID() : 
+        'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
+          const r = Math.random() * 16 | 0;
+          const v = c == 'x' ? r : (r & 0x3 | 0x8);
+          return v.toString(16);
+        });
+      headers["x-vscode-user-agent-library-version"] = "electron-fetch";
+      headers["X-Initiator"] = "user";
+      headers["Accept"] = "application/json";
+      break;
+
+    case "codex":
+    case "qwen":
+    case "openai":
+    case "openrouter":
+      headers["Authorization"] = `Bearer ${credentials.apiKey || credentials.accessToken}`;
+      break;
+
+    case "glm":
+    case "kimi":
+    case "minimax":
+      // Claude-compatible API providers use x-api-key
+      headers["x-api-key"] = credentials.apiKey;
+      break;
+
+    default:
+      headers["Authorization"] = `Bearer ${credentials.apiKey || credentials.accessToken}`;
+      break;
+  }
+
+  // Stream accept header
+  if (stream) {
+    headers["Accept"] = "text/event-stream";
+  }
+
+  return headers;
+}
+
+// Get target format for provider
+export function getTargetFormat(provider) {
+  const config = getProviderConfig(provider);
+  return config.format || "openai";
+}
+
+// Check if last message is from user
+export function isLastMessageFromUser(body) {
+  const messages = body.messages || body.contents;
+  if (!messages?.length) return true;
+  const lastMsg = messages[messages.length - 1];
+  return lastMsg?.role === "user";
+}
+
+// Check if request has thinking config
+export function hasThinkingConfig(body) {
+  return !!(body.reasoning_effort || body.thinking?.type === "enabled");
+}
+
+// Normalize thinking config based on last message role
+// - If lastMessage is not user → remove thinking config
+// - If lastMessage is user AND has thinking config → keep it (force enable)
+export function normalizeThinkingConfig(body) {
+  if (!isLastMessageFromUser(body)) {
+    delete body.reasoning_effort;
+    delete body.thinking;
+  }
+  return body;
+}
+

open-sse/services/tokenRefresh.js

@@ -0,0 +1,542 @@
+import { PROVIDERS, OAUTH_ENDPOINTS } from "../config/constants.js";
+
+// Token expiry buffer (refresh if expires within 5 minutes)
+export const TOKEN_EXPIRY_BUFFER_MS = 5 * 60 * 1000;
+
+/**
+ * Refresh OAuth access token using refresh token
+ */
+export async function refreshAccessToken(provider, refreshToken, credentials, log) {
+  const config = PROVIDERS[provider];
+  
+  if (!config || !config.refreshUrl) {
+    log?.warn?.("TOKEN_REFRESH", `No refresh URL configured for provider: ${provider}`);
+    return null;
+  }
+
+  if (!refreshToken) {
+    log?.warn?.("TOKEN_REFRESH", `No refresh token available for provider: ${provider}`);
+    return null;
+  }
+
+  try {
+    const response = await fetch(config.refreshUrl, {
+      method: "POST",
+      headers: {
+        "Content-Type": "application/x-www-form-urlencoded",
+        Accept: "application/json",
+      },
+      body: new URLSearchParams({
+        grant_type: "refresh_token",
+        refresh_token: refreshToken,
+        client_id: config.clientId,
+        client_secret: config.clientSecret,
+      }),
+    });
+
+    if (!response.ok) {
+      const errorText = await response.text();
+      log?.error?.("TOKEN_REFRESH", `Failed to refresh token for ${provider}`, {
+        status: response.status,
+        error: errorText,
+      });
+      return null;
+    }
+
+    const tokens = await response.json();
+    
+    log?.info?.("TOKEN_REFRESH", `Successfully refreshed token for ${provider}`, {
+      hasNewAccessToken: !!tokens.access_token,
+      hasNewRefreshToken: !!tokens.refresh_token,
+      expiresIn: tokens.expires_in,
+    });
+
+    return {
+      accessToken: tokens.access_token,
+      refreshToken: tokens.refresh_token || refreshToken,
+      expiresIn: tokens.expires_in,
+    };
+  } catch (error) {
+    log?.error?.("TOKEN_REFRESH", `Error refreshing token for ${provider}`, {
+      error: error.message,
+    });
+    return null;
+  }
+}
+
+/**
+ * Specialized refresh for Claude OAuth tokens
+ */
+export async function refreshClaudeOAuthToken(refreshToken, log) {
+  const response = await fetch(OAUTH_ENDPOINTS.anthropic.token, {
+    method: "POST",
+    headers: {
+      "Content-Type": "application/json",
+      Accept: "application/json",
+    },
+    body: JSON.stringify({
+      grant_type: "refresh_token",
+      refresh_token: refreshToken,
+      client_id: PROVIDERS.claude.clientId,
+    }),
+  });
+
+  if (!response.ok) {
+    const errorText = await response.text();
+    log?.error?.("TOKEN_REFRESH", "Failed to refresh Claude OAuth token", {
+      status: response.status,
+      error: errorText,
+    });
+    return null;
+  }
+
+  const tokens = await response.json();
+  
+  log?.info?.("TOKEN_REFRESH", "Successfully refreshed Claude OAuth token", {
+    hasNewAccessToken: !!tokens.access_token,
+    hasNewRefreshToken: !!tokens.refresh_token,
+    expiresIn: tokens.expires_in,
+  });
+
+  return {
+    accessToken: tokens.access_token,
+    refreshToken: tokens.refresh_token || refreshToken,
+    expiresIn: tokens.expires_in,
+  };
+}
+
+/**
+ * Specialized refresh for Google providers (Gemini, Antigravity)
+ */
+export async function refreshGoogleToken(refreshToken, clientId, clientSecret, log) {
+  const response = await fetch(OAUTH_ENDPOINTS.google.token, {
+    method: "POST",
+    headers: {
+      "Content-Type": "application/x-www-form-urlencoded",
+      Accept: "application/json",
+    },
+    body: new URLSearchParams({
+      grant_type: "refresh_token",
+      refresh_token: refreshToken,
+      client_id: clientId,
+      client_secret: clientSecret,
+    }),
+  });
+
+  if (!response.ok) {
+    const errorText = await response.text();
+    log?.error?.("TOKEN_REFRESH", "Failed to refresh Google token", {
+      status: response.status,
+      error: errorText,
+    });
+    return null;
+  }
+
+  const tokens = await response.json();
+  
+  log?.info?.("TOKEN_REFRESH", "Successfully refreshed Google token", {
+    hasNewAccessToken: !!tokens.access_token,
+    hasNewRefreshToken: !!tokens.refresh_token,
+    expiresIn: tokens.expires_in,
+  });
+
+  return {
+    accessToken: tokens.access_token,
+    refreshToken: tokens.refresh_token || refreshToken,
+    expiresIn: tokens.expires_in,
+  };
+}
+
+/**
+ * Specialized refresh for Qwen OAuth tokens
+ */
+export async function refreshQwenToken(refreshToken, log) {
+  const endpoint = OAUTH_ENDPOINTS.qwen.token;
+  
+  try {
+    const response = await fetch(endpoint, {
+      method: "POST",
+      headers: {
+        "Content-Type": "application/x-www-form-urlencoded",
+        Accept: "application/json",
+      },
+      body: new URLSearchParams({
+        grant_type: "refresh_token",
+        refresh_token: refreshToken,
+        client_id: PROVIDERS.qwen.clientId,
+      }),
+    });
+
+    if (response.status === 200) {
+      const tokens = await response.json();
+      
+      log?.info?.("TOKEN_REFRESH", "Successfully refreshed Qwen token", {
+        hasNewAccessToken: !!tokens.access_token,
+        hasNewRefreshToken: !!tokens.refresh_token,
+        expiresIn: tokens.expires_in,
+      });
+
+      return {
+        accessToken: tokens.access_token,
+        refreshToken: tokens.refresh_token || refreshToken,
+        expiresIn: tokens.expires_in,
+      };
+    } else {
+      const errorText = await response.text().catch(() => "");
+      log?.warn?.("TOKEN_REFRESH", `Error with Qwen endpoint`, {
+        status: response.status,
+        error: errorText,
+      });
+    }
+  } catch (error) {
+    log?.warn?.("TOKEN_REFRESH", `Network error trying Qwen endpoint`, {
+      error: error.message,
+    });
+  }
+
+  log?.error?.("TOKEN_REFRESH", "Failed to refresh Qwen token");
+  return null;
+}
+
+/**
+ * Specialized refresh for Codex (OpenAI) OAuth tokens
+ */
+export async function refreshCodexToken(refreshToken, log) {
+  const response = await fetch(OAUTH_ENDPOINTS.openai.token, {
+    method: "POST",
+    headers: {
+      "Content-Type": "application/x-www-form-urlencoded",
+      Accept: "application/json",
+    },
+    body: new URLSearchParams({
+      grant_type: "refresh_token",
+      refresh_token: refreshToken,
+      client_id: PROVIDERS.codex.clientId,
+      scope: "openid profile email offline_access",
+    }),
+  });
+
+  if (!response.ok) {
+    const errorText = await response.text();
+    log?.error?.("TOKEN_REFRESH", "Failed to refresh Codex token", {
+      status: response.status,
+      error: errorText,
+    });
+    return null;
+  }
+
+  const tokens = await response.json();
+  
+  log?.info?.("TOKEN_REFRESH", "Successfully refreshed Codex token", {
+    hasNewAccessToken: !!tokens.access_token,
+    hasNewRefreshToken: !!tokens.refresh_token,
+    expiresIn: tokens.expires_in,
+  });
+
+  return {
+    accessToken: tokens.access_token,
+    refreshToken: tokens.refresh_token || refreshToken,
+    expiresIn: tokens.expires_in,
+  };
+}
+
+/**
+ * Specialized refresh for iFlow OAuth tokens
+ */
+export async function refreshIflowToken(refreshToken, log) {
+  const basicAuth = btoa(`${PROVIDERS.iflow.clientId}:${PROVIDERS.iflow.clientSecret}`);
+  
+  const response = await fetch(OAUTH_ENDPOINTS.iflow.token, {
+    method: "POST",
+    headers: {
+      "Content-Type": "application/x-www-form-urlencoded",
+      Accept: "application/json",
+      Authorization: `Basic ${basicAuth}`,
+    },
+    body: new URLSearchParams({
+      grant_type: "refresh_token",
+      refresh_token: refreshToken,
+      client_id: PROVIDERS.iflow.clientId,
+      client_secret: PROVIDERS.iflow.clientSecret,
+    }),
+  });
+
+  if (!response.ok) {
+    const errorText = await response.text();
+    log?.error?.("TOKEN_REFRESH", "Failed to refresh iFlow token", {
+      status: response.status,
+      error: errorText,
+    });
+    return null;
+  }
+
+  const tokens = await response.json();
+  
+  log?.info?.("TOKEN_REFRESH", "Successfully refreshed iFlow token", {
+    hasNewAccessToken: !!tokens.access_token,
+    hasNewRefreshToken: !!tokens.refresh_token,
+    expiresIn: tokens.expires_in,
+  });
+
+  return {
+    accessToken: tokens.access_token,
+    refreshToken: tokens.refresh_token || refreshToken,
+    expiresIn: tokens.expires_in,
+  };
+}
+
+/**
+ * Specialized refresh for GitHub Copilot OAuth tokens
+ */
+export async function refreshGitHubToken(refreshToken, log) {
+  const response = await fetch(OAUTH_ENDPOINTS.github.token, {
+    method: "POST",
+    headers: {
+      "Content-Type": "application/x-www-form-urlencoded",
+      Accept: "application/json",
+    },
+    body: new URLSearchParams({
+      grant_type: "refresh_token",
+      refresh_token: refreshToken,
+      client_id: PROVIDERS.github.clientId,
+      client_secret: PROVIDERS.github.clientSecret,
+    }),
+  });
+
+  if (!response.ok) {
+    const errorText = await response.text();
+    log?.error?.("TOKEN_REFRESH", "Failed to refresh GitHub token", {
+      status: response.status,
+      error: errorText,
+    });
+    return null;
+  }
+
+  const tokens = await response.json();
+  
+  log?.info?.("TOKEN_REFRESH", "Successfully refreshed GitHub token", {
+    hasNewAccessToken: !!tokens.access_token,
+    hasNewRefreshToken: !!tokens.refresh_token,
+    expiresIn: tokens.expires_in,
+  });
+
+  return {
+    accessToken: tokens.access_token,
+    refreshToken: tokens.refresh_token || refreshToken,
+    expiresIn: tokens.expires_in,
+  };
+}
+
+/**
+ * Refresh GitHub Copilot token using GitHub access token
+ */
+export async function refreshCopilotToken(githubAccessToken, log) {
+  try {
+    const response = await fetch("https://api.github.com/copilot_internal/v2/token", {
+      headers: {
+        "Authorization": `Bearer ${githubAccessToken}`,
+        "User-Agent": "GitHub-Copilot/1.0",
+        "Accept": "*/*"
+      }
+    });
+
+    if (!response.ok) {
+      const errorText = await response.text();
+      log?.error?.("TOKEN_REFRESH", "Failed to refresh Copilot token", {
+        status: response.status,
+        error: errorText
+      });
+      return null;
+    }
+
+    const data = await response.json();
+    
+    log?.info?.("TOKEN_REFRESH", "Successfully refreshed Copilot token", {
+      hasToken: !!data.token,
+      expiresAt: data.expires_at
+    });
+
+    return {
+      token: data.token,
+      expiresAt: data.expires_at
+    };
+  } catch (error) {
+    log?.error?.("TOKEN_REFRESH", "Error refreshing Copilot token", {
+      error: error.message
+    });
+    return null;
+  }
+}
+
+/**
+ * Get access token for a specific provider
+ */
+export async function getAccessToken(provider, credentials, log) {
+  if (!credentials || !credentials.refreshToken) {
+    log?.warn?.("TOKEN_REFRESH", `No refresh token available for provider: ${provider}`);
+    return null;
+  }
+
+  switch (provider) {
+    case "gemini":
+    case "gemini-cli":
+    case "antigravity":
+      return await refreshGoogleToken(
+        credentials.refreshToken,
+        PROVIDERS[provider].clientId,
+        PROVIDERS[provider].clientSecret,
+        log
+      );
+    
+    case "claude":
+      return await refreshClaudeOAuthToken(credentials.refreshToken, log);
+    
+    case "codex":
+      return await refreshCodexToken(credentials.refreshToken, log);
+    
+    case "qwen":
+      return await refreshQwenToken(credentials.refreshToken, log);
+    
+    case "iflow":
+      return await refreshIflowToken(credentials.refreshToken, log);
+    
+    case "github":
+      return await refreshGitHubToken(credentials.refreshToken, log);
+    
+    default:
+      log?.warn?.("TOKEN_REFRESH", `Unsupported provider for token refresh: ${provider}`);
+      return null;
+  }
+}
+
+/**
+ * Refresh token by provider type (helper for handlers)
+ */
+export async function refreshTokenByProvider(provider, credentials, log) {
+  if (!credentials.refreshToken) return null;
+
+  switch (provider) {
+    case "gemini-cli":
+    case "antigravity":
+      return refreshGoogleToken(
+        credentials.refreshToken,
+        PROVIDERS[provider].clientId,
+        PROVIDERS[provider].clientSecret,
+        log
+      );
+    case "claude":
+      return refreshClaudeOAuthToken(credentials.refreshToken, log);
+    case "codex":
+      return refreshCodexToken(credentials.refreshToken, log);
+    case "qwen":
+      return refreshQwenToken(credentials.refreshToken, log);
+    case "iflow":
+      return refreshIflowToken(credentials.refreshToken, log);
+    case "github":
+      return refreshGitHubToken(credentials.refreshToken, log);
+    default:
+      return refreshAccessToken(provider, credentials.refreshToken, credentials, log);
+  }
+}
+
+/**
+ * Format credentials for provider
+ */
+export function formatProviderCredentials(provider, credentials, log) {
+  const config = PROVIDERS[provider];
+  if (!config) {
+    log?.warn?.("TOKEN_REFRESH", `No configuration found for provider: ${provider}`);
+    return null;
+  }
+
+  switch (provider) {
+    case "gemini":
+      return {
+        apiKey: credentials.apiKey,
+        accessToken: credentials.accessToken,
+        projectId: credentials.projectId
+      };
+    
+    case "claude":
+      return {
+        apiKey: credentials.apiKey,
+        accessToken: credentials.accessToken
+      };
+    
+    case "codex":
+    case "qwen":
+    case "iflow":
+    case "openai":
+    case "openrouter":
+      return {
+        apiKey: credentials.apiKey,
+        accessToken: credentials.accessToken
+      };
+    
+    case "antigravity":
+    case "gemini-cli":
+      return {
+        accessToken: credentials.accessToken,
+        refreshToken: credentials.refreshToken
+      };
+    
+    default:
+      return {
+        apiKey: credentials.apiKey,
+        accessToken: credentials.accessToken,
+        refreshToken: credentials.refreshToken
+      };
+  }
+}
+
+/**
+ * Get all access tokens for a user
+ */
+export async function getAllAccessTokens(userInfo, log) {
+  const results = {};
+  
+  if (userInfo.connections && Array.isArray(userInfo.connections)) {
+    for (const connection of userInfo.connections) {
+      if (connection.isActive && connection.provider) {
+        const token = await getAccessToken(connection.provider, {
+          refreshToken: connection.refreshToken
+        }, log);
+        
+        if (token) {
+          results[connection.provider] = token;
+        }
+      }
+    }
+  }
+  
+  return results;
+}
+
+/**
+ * Refresh token with retry and exponential backoff
+ * Retries on failure with increasing delay: 1s, 2s, 3s...
+ * @param {function} refreshFn - Async function that returns token or null
+ * @param {number} maxRetries - Max retry attempts (default 3)
+ * @param {object} log - Logger instance (optional)
+ * @returns {Promise<object|null>} Token result or null if all retries fail
+ */
+export async function refreshWithRetry(refreshFn, maxRetries = 3, log = null) {
+  for (let attempt = 0; attempt < maxRetries; attempt++) {
+    if (attempt > 0) {
+      const delay = attempt * 1000;
+      log?.debug?.("TOKEN_REFRESH", `Retry ${attempt}/${maxRetries} after ${delay}ms`);
+      await new Promise(r => setTimeout(r, delay));
+    }
+
+    try {
+      const result = await refreshFn();
+      if (result) return result;
+    } catch (error) {
+      log?.warn?.("TOKEN_REFRESH", `Attempt ${attempt + 1}/${maxRetries} failed: ${error.message}`);
+    }
+  }
+
+  log?.error?.("TOKEN_REFRESH", `All ${maxRetries} retry attempts failed`);
+  return null;
+}
+

open-sse/services/usage.js

@@ -0,0 +1,398 @@
+/**
+ * Usage Fetcher - Get usage data from provider APIs
+ */
+
+// GitHub API config
+const GITHUB_CONFIG = {
+  apiVersion: "2022-11-28",
+  userAgent: "GitHubCopilotChat/0.26.7",
+};
+
+// Antigravity API config (from Quotio)
+const ANTIGRAVITY_CONFIG = {
+  quotaApiUrl: "https://cloudcode-pa.googleapis.com/v1internal:fetchAvailableModels",
+  loadProjectApiUrl: "https://cloudcode-pa.googleapis.com/v1internal:loadCodeAssist",
+  tokenUrl: "https://oauth2.googleapis.com/token",
+  clientId: "1071006060591-tmhssin2h21lcre235vtolojh4g403ep.apps.googleusercontent.com",
+  clientSecret: "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",
+  userAgent: "antigravity/1.11.3 Darwin/arm64",
+};
+
+// Codex (OpenAI) API config
+const CODEX_CONFIG = {
+  usageUrl: "https://chatgpt.com/backend-api/wham/usage",
+};
+
+// Claude API config
+const CLAUDE_CONFIG = {
+  usageUrl: "https://api.anthropic.com/v1/organizations/{org_id}/usage",
+  settingsUrl: "https://api.anthropic.com/v1/settings",
+};
+
+/**
+ * Get usage data for a provider connection
+ * @param {Object} connection - Provider connection with accessToken
+ * @returns {Object} Usage data with quotas
+ */
+export async function getUsageForProvider(connection) {
+  const { provider, accessToken, providerSpecificData } = connection;
+
+  switch (provider) {
+    case "github":
+      return await getGitHubUsage(accessToken, providerSpecificData);
+    case "gemini-cli":
+      return await getGeminiUsage(accessToken);
+    case "antigravity":
+      return await getAntigravityUsage(accessToken);
+    case "claude":
+      return await getClaudeUsage(accessToken);
+    case "codex":
+      return await getCodexUsage(accessToken);
+    case "qwen":
+      return await getQwenUsage(accessToken, providerSpecificData);
+    case "iflow":
+      return await getIflowUsage(accessToken);
+    default:
+      return { message: `Usage API not implemented for ${provider}` };
+  }
+}
+
+/**
+ * GitHub Copilot Usage
+ */
+async function getGitHubUsage(accessToken, providerSpecificData) {
+  try {
+    const response = await fetch("https://api.github.com/copilot_internal/user", {
+      headers: {
+        "Authorization": `Bearer ${accessToken}`,
+        "Accept": "application/json",
+        "X-GitHub-Api-Version": GITHUB_CONFIG.apiVersion,
+        "User-Agent": GITHUB_CONFIG.userAgent,
+      },
+    });
+
+    if (!response.ok) {
+      const error = await response.text();
+      throw new Error(`GitHub API error: ${error}`);
+    }
+
+    const data = await response.json();
+
+    // Handle different response formats (paid vs free)
+    if (data.quota_snapshots) {
+      // Paid plan format
+      const snapshots = data.quota_snapshots;
+      return {
+        plan: data.copilot_plan,
+        resetDate: data.quota_reset_date,
+        quotas: {
+          chat: formatGitHubQuotaSnapshot(snapshots.chat),
+          completions: formatGitHubQuotaSnapshot(snapshots.completions),
+          premium_interactions: formatGitHubQuotaSnapshot(snapshots.premium_interactions),
+        },
+      };
+    } else if (data.monthly_quotas || data.limited_user_quotas) {
+      // Free/limited plan format
+      const monthlyQuotas = data.monthly_quotas || {};
+      const usedQuotas = data.limited_user_quotas || {};
+      
+      return {
+        plan: data.copilot_plan || data.access_type_sku,
+        resetDate: data.limited_user_reset_date,
+        quotas: {
+          chat: {
+            used: usedQuotas.chat || 0,
+            total: monthlyQuotas.chat || 0,
+            unlimited: false,
+          },
+          completions: {
+            used: usedQuotas.completions || 0,
+            total: monthlyQuotas.completions || 0,
+            unlimited: false,
+          },
+        },
+      };
+    }
+
+    return { message: "GitHub Copilot connected. Unable to parse quota data." };
+  } catch (error) {
+    throw new Error(`Failed to fetch GitHub usage: ${error.message}`);
+  }
+}
+
+function formatGitHubQuotaSnapshot(quota) {
+  if (!quota) return { used: 0, total: 0, unlimited: true };
+  
+  return {
+    used: quota.entitlement - quota.remaining,
+    total: quota.entitlement,
+    remaining: quota.remaining,
+    unlimited: quota.unlimited || false,
+  };
+}
+
+/**
+ * Gemini CLI Usage (Google Cloud)
+ */
+async function getGeminiUsage(accessToken) {
+  try {
+    // Gemini CLI uses Google Cloud quotas
+    // Try to get quota info from Cloud Resource Manager
+    const response = await fetch(
+      "https://cloudresourcemanager.googleapis.com/v1/projects?filter=lifecycleState:ACTIVE",
+      {
+        headers: {
+          Authorization: `Bearer ${accessToken}`,
+          Accept: "application/json",
+        },
+      }
+    );
+
+    if (!response.ok) {
+      // Quota API may not be accessible, return generic message
+      return { message: "Gemini CLI uses Google Cloud quotas. Check Google Cloud Console for details." };
+    }
+
+    return { message: "Gemini CLI connected. Usage tracked via Google Cloud Console." };
+  } catch (error) {
+    return { message: "Unable to fetch Gemini usage. Check Google Cloud Console." };
+  }
+}
+
+/**
+ * Antigravity Usage - Fetch quota from Google Cloud Code API
+ */
+async function getAntigravityUsage(accessToken, providerSpecificData) {
+  try {
+    // First get project ID from subscription info
+    const projectId = await getAntigravityProjectId(accessToken);
+    
+    // Fetch quota data
+    const response = await fetch(ANTIGRAVITY_CONFIG.quotaApiUrl, {
+      method: "POST",
+      headers: {
+        "Authorization": `Bearer ${accessToken}`,
+        "User-Agent": ANTIGRAVITY_CONFIG.userAgent,
+        "Content-Type": "application/json",
+      },
+      body: JSON.stringify(projectId ? { project: projectId } : {}),
+    });
+
+    if (response.status === 403) {
+      return { message: "Antigravity access forbidden. Check subscription." };
+    }
+
+    if (!response.ok) {
+      throw new Error(`Antigravity API error: ${response.status}`);
+    }
+
+    const data = await response.json();
+    const quotas = {};
+    
+    // Parse model quotas
+    if (data.models) {
+      for (const [name, info] of Object.entries(data.models)) {
+        // Only include gemini and claude models
+        if (!name.includes("gemini") && !name.includes("claude")) continue;
+        
+        if (info.quotaInfo) {
+          const percentage = (info.quotaInfo.remainingFraction || 0) * 100;
+          quotas[name] = {
+            remaining: percentage,
+            resetTime: info.quotaInfo.resetTime || "",
+            unlimited: false,
+          };
+        }
+      }
+    }
+
+    // Get subscription info for plan type
+    const subscriptionInfo = await getAntigravitySubscriptionInfo(accessToken);
+
+    return {
+      plan: subscriptionInfo?.currentTier?.name || "Unknown",
+      quotas,
+      subscriptionInfo,
+    };
+  } catch (error) {
+    return { message: `Antigravity error: ${error.message}` };
+  }
+}
+
+/**
+ * Get Antigravity project ID from subscription info
+ */
+async function getAntigravityProjectId(accessToken) {
+  try {
+    const info = await getAntigravitySubscriptionInfo(accessToken);
+    return info?.cloudaicompanionProject || null;
+  } catch {
+    return null;
+  }
+}
+
+/**
+ * Get Antigravity subscription info
+ */
+async function getAntigravitySubscriptionInfo(accessToken) {
+  try {
+    const response = await fetch(ANTIGRAVITY_CONFIG.loadProjectApiUrl, {
+      method: "POST",
+      headers: {
+        "Authorization": `Bearer ${accessToken}`,
+        "User-Agent": ANTIGRAVITY_CONFIG.userAgent,
+        "Content-Type": "application/json",
+      },
+      body: JSON.stringify({ metadata: { ideType: "ANTIGRAVITY" } }),
+    });
+
+    if (!response.ok) return null;
+
+    return await response.json();
+  } catch {
+    return null;
+  }
+}
+
+/**
+ * Claude Usage - Try to fetch from Anthropic API
+ */
+async function getClaudeUsage(accessToken) {
+  try {
+    // Try to get organization/account settings first
+    const settingsResponse = await fetch("https://api.anthropic.com/v1/settings", {
+      method: "GET",
+      headers: {
+        "Authorization": `Bearer ${accessToken}`,
+        "Content-Type": "application/json",
+        "anthropic-version": "2023-06-01",
+      },
+    });
+
+    if (settingsResponse.ok) {
+      const settings = await settingsResponse.json();
+      
+      // Try usage endpoint if we have org info
+      if (settings.organization_id) {
+        const usageResponse = await fetch(
+          `https://api.anthropic.com/v1/organizations/${settings.organization_id}/usage`,
+          {
+            method: "GET",
+            headers: {
+              "Authorization": `Bearer ${accessToken}`,
+              "Content-Type": "application/json",
+              "anthropic-version": "2023-06-01",
+            },
+          }
+        );
+
+        if (usageResponse.ok) {
+          const usage = await usageResponse.json();
+          return {
+            plan: settings.plan || "Unknown",
+            organization: settings.organization_name,
+            quotas: usage,
+          };
+        }
+      }
+
+      return {
+        plan: settings.plan || "Unknown",
+        organization: settings.organization_name,
+        message: "Claude connected. Usage details require admin access.",
+      };
+    }
+
+    // If settings API fails, OAuth token may not have required scope
+    return { message: "Claude connected. Usage API requires admin permissions." };
+  } catch (error) {
+    return { message: `Claude connected. Unable to fetch usage: ${error.message}` };
+  }
+}
+
+/**
+ * Codex (OpenAI) Usage - Fetch from ChatGPT backend API
+ */
+async function getCodexUsage(accessToken) {
+  try {
+    const response = await fetch(CODEX_CONFIG.usageUrl, {
+      method: "GET",
+      headers: {
+        "Authorization": `Bearer ${accessToken}`,
+        "Accept": "application/json",
+      },
+    });
+
+    if (!response.ok) {
+      throw new Error(`Codex API error: ${response.status}`);
+    }
+
+    const data = await response.json();
+    
+    // Parse rate limit info
+    const rateLimit = data.rate_limit || {};
+    const primaryWindow = rateLimit.primary_window || {};
+    const secondaryWindow = rateLimit.secondary_window || {};
+
+    // Calculate reset dates
+    const sessionResetAt = primaryWindow.reset_at 
+      ? new Date(primaryWindow.reset_at * 1000).toISOString() 
+      : null;
+    const weeklyResetAt = secondaryWindow.reset_at 
+      ? new Date(secondaryWindow.reset_at * 1000).toISOString() 
+      : null;
+
+    return {
+      plan: data.plan_type || "unknown",
+      limitReached: rateLimit.limit_reached || false,
+      quotas: {
+        session: {
+          used: primaryWindow.used_percent || 0,
+          total: 100,
+          remaining: 100 - (primaryWindow.used_percent || 0),
+          resetTime: sessionResetAt,
+          unlimited: false,
+        },
+        weekly: {
+          used: secondaryWindow.used_percent || 0,
+          total: 100,
+          remaining: 100 - (secondaryWindow.used_percent || 0),
+          resetTime: weeklyResetAt,
+          unlimited: false,
+        },
+      },
+    };
+  } catch (error) {
+    throw new Error(`Failed to fetch Codex usage: ${error.message}`);
+  }
+}
+
+/**
+ * Qwen Usage
+ */
+async function getQwenUsage(accessToken, providerSpecificData) {
+  try {
+    const resourceUrl = providerSpecificData?.resourceUrl;
+    if (!resourceUrl) {
+      return { message: "Qwen connected. No resource URL available." };
+    }
+
+    // Qwen may have usage endpoint at resource URL
+    return { message: "Qwen connected. Usage tracked per request." };
+  } catch (error) {
+    return { message: "Unable to fetch Qwen usage." };
+  }
+}
+
+/**
+ * iFlow Usage
+ */
+async function getIflowUsage(accessToken) {
+  try {
+    // iFlow may have usage endpoint
+    return { message: "iFlow connected. Usage tracked per request." };
+  } catch (error) {
+    return { message: "Unable to fetch iFlow usage." };
+  }
+}
+

open-sse/transformer/responsesTransformer.js

@@ -0,0 +1,439 @@
+/**
+ * Responses API Transformer
+ * Converts OpenAI Chat Completions SSE to Codex Responses API SSE format
+ * Can be used in both Next.js and Cloudflare Workers
+ */
+
+import fs from "fs";
+import path from "path";
+
+// Create log directory for responses (Node.js only)
+export function createResponsesLogger(model, logsDir = null) {
+  // Skip logging in worker environment (no fs)
+  if (typeof fs.mkdirSync !== "function") {
+    return null;
+  }
+
+  const timestamp = new Date().toISOString().replace(/[:.]/g, "").slice(0, 15);
+  const uniqueId = Math.random().toString(36).slice(2, 8);
+  const baseDir = logsDir || (typeof process !== "undefined" ? process.cwd() : ".");
+  const logDir = path.join(baseDir, "logs", `responses_${model}_${timestamp}_${uniqueId}`);
+  
+  try {
+    fs.mkdirSync(logDir, { recursive: true });
+  } catch {
+    return null;
+  }
+
+  let inputEvents = [];
+  let outputEvents = [];
+
+  return {
+    logInput: (event) => {
+      inputEvents.push(event);
+    },
+    logOutput: (event) => {
+      outputEvents.push(event);
+    },
+    flush: () => {
+      try {
+        fs.writeFileSync(path.join(logDir, "1_input_stream.txt"), inputEvents.join("\n"));
+        fs.writeFileSync(path.join(logDir, "2_output_stream.txt"), outputEvents.join("\n"));
+      } catch (e) {
+        console.log("[RESPONSES] Failed to write logs:", e.message);
+      }
+    }
+  };
+}
+
+/**
+ * Create TransformStream that converts Chat Completions SSE to Responses API SSE
+ * @param {Object} logger - Optional logger instance
+ * @returns {TransformStream}
+ */
+export function createResponsesApiTransformStream(logger = null) {
+  const state = {
+    seq: 0,
+    responseId: `resp_${Date.now()}`,
+    created: Math.floor(Date.now() / 1000),
+    started: false,
+    msgTextBuf: {},
+    msgItemAdded: {},
+    msgContentAdded: {},
+    msgItemDone: {},
+    reasoningId: "",
+    reasoningIndex: -1,
+    reasoningBuf: "",
+    reasoningPartAdded: false,
+    reasoningDone: false,
+    inThinking: false,
+    funcArgsBuf: {},
+    funcNames: {},
+    funcCallIds: {},
+    funcArgsDone: {},
+    funcItemDone: {},
+    buffer: "",
+    completedSent: false
+  };
+
+  const encoder = new TextEncoder();
+  const nextSeq = () => ++state.seq;
+  
+  const emit = (controller, eventType, data) => {
+    data.sequence_number = nextSeq();
+    const output = `event: ${eventType}\ndata: ${JSON.stringify(data)}\n\n`;
+    logger?.logOutput(output.trim());
+    controller.enqueue(encoder.encode(output));
+  };
+
+  // Helper to start reasoning
+  const startReasoning = (controller, idx) => {
+    if (!state.reasoningId) {
+      state.reasoningId = `rs_${state.responseId}_${idx}`;
+      state.reasoningIndex = idx;
+      
+      emit(controller, "response.output_item.added", {
+        type: "response.output_item.added",
+        output_index: idx,
+        item: {
+          id: state.reasoningId,
+          type: "reasoning",
+          summary: []
+        }
+      });
+
+      emit(controller, "response.reasoning_summary_part.added", {
+        type: "response.reasoning_summary_part.added",
+        item_id: state.reasoningId,
+        output_index: idx,
+        summary_index: 0,
+        part: { type: "summary_text", text: "" }
+      });
+      state.reasoningPartAdded = true;
+    }
+  };
+
+  const emitReasoningDelta = (controller, text) => {
+    if (!text) return;
+    state.reasoningBuf += text;
+    emit(controller, "response.reasoning_summary_text.delta", {
+      type: "response.reasoning_summary_text.delta",
+      item_id: state.reasoningId,
+      output_index: state.reasoningIndex,
+      summary_index: 0,
+      delta: text
+    });
+  };
+
+  const closeReasoning = (controller) => {
+    if (state.reasoningId && !state.reasoningDone) {
+      state.reasoningDone = true;
+      
+      emit(controller, "response.reasoning_summary_text.done", {
+        type: "response.reasoning_summary_text.done",
+        item_id: state.reasoningId,
+        output_index: state.reasoningIndex,
+        summary_index: 0,
+        text: state.reasoningBuf
+      });
+
+      emit(controller, "response.reasoning_summary_part.done", {
+        type: "response.reasoning_summary_part.done",
+        item_id: state.reasoningId,
+        output_index: state.reasoningIndex,
+        summary_index: 0,
+        part: { type: "summary_text", text: state.reasoningBuf }
+      });
+
+      emit(controller, "response.output_item.done", {
+        type: "response.output_item.done",
+        output_index: state.reasoningIndex,
+        item: {
+          id: state.reasoningId,
+          type: "reasoning",
+          summary: [{ type: "summary_text", text: state.reasoningBuf }]
+        }
+      });
+    }
+  };
+
+  const closeMessage = (controller, idx) => {
+    if (state.msgItemAdded[idx] && !state.msgItemDone[idx]) {
+      state.msgItemDone[idx] = true;
+      const fullText = state.msgTextBuf[idx] || "";
+      const msgId = `msg_${state.responseId}_${idx}`;
+
+      emit(controller, "response.output_text.done", {
+        type: "response.output_text.done",
+        item_id: msgId,
+        output_index: parseInt(idx),
+        content_index: 0,
+        text: fullText,
+        logprobs: []
+      });
+
+      emit(controller, "response.content_part.done", {
+        type: "response.content_part.done",
+        item_id: msgId,
+        output_index: parseInt(idx),
+        content_index: 0,
+        part: { type: "output_text", annotations: [], logprobs: [], text: fullText }
+      });
+
+      emit(controller, "response.output_item.done", {
+        type: "response.output_item.done",
+        output_index: parseInt(idx),
+        item: {
+          id: msgId,
+          type: "message",
+          content: [{ type: "output_text", annotations: [], logprobs: [], text: fullText }],
+          role: "assistant"
+        }
+      });
+    }
+  };
+
+  const closeToolCall = (controller, idx) => {
+    const callId = state.funcCallIds[idx];
+    if (callId && !state.funcItemDone[idx]) {
+      const args = state.funcArgsBuf[idx] || "{}";
+      
+      emit(controller, "response.function_call_arguments.done", {
+        type: "response.function_call_arguments.done",
+        item_id: `fc_${callId}`,
+        output_index: parseInt(idx),
+        arguments: args
+      });
+
+      emit(controller, "response.output_item.done", {
+        type: "response.output_item.done",
+        output_index: parseInt(idx),
+        item: {
+          id: `fc_${callId}`,
+          type: "function_call",
+          arguments: args,
+          call_id: callId,
+          name: state.funcNames[idx] || ""
+        }
+      });
+
+      state.funcItemDone[idx] = true;
+      state.funcArgsDone[idx] = true;
+    }
+  };
+
+  const sendCompleted = (controller) => {
+    if (!state.completedSent) {
+      state.completedSent = true;
+      emit(controller, "response.completed", {
+        type: "response.completed",
+        response: {
+          id: state.responseId,
+          object: "response",
+          created_at: state.created,
+          status: "completed",
+          background: false,
+          error: null
+        }
+      });
+    }
+  };
+
+  return new TransformStream({
+    transform(chunk, controller) {
+      const text = new TextDecoder().decode(chunk);
+      logger?.logInput(text.trim());
+      state.buffer += text;
+
+      const messages = state.buffer.split("\n\n");
+      state.buffer = messages.pop() || "";
+
+      for (const msg of messages) {
+        if (!msg.trim()) continue;
+
+        const dataMatch = msg.match(/^data:\s*(.+)$/m);
+        if (!dataMatch) continue;
+
+        const dataStr = dataMatch[1].trim();
+        if (dataStr === "[DONE]") continue;
+
+        let parsed;
+        try {
+          parsed = JSON.parse(dataStr);
+        } catch {
+          continue;
+        }
+
+        if (!parsed.choices?.length) continue;
+        
+        const choice = parsed.choices[0];
+        const idx = choice.index || 0;
+        const delta = choice.delta || {};
+
+        // Emit initial events
+        if (!state.started) {
+          state.started = true;
+          state.responseId = parsed.id ? `resp_${parsed.id}` : state.responseId;
+          
+          emit(controller, "response.created", {
+            type: "response.created",
+            response: {
+              id: state.responseId,
+              object: "response",
+              created_at: state.created,
+              status: "in_progress",
+              background: false,
+              error: null,
+              output: []
+            }
+          });
+
+          emit(controller, "response.in_progress", {
+            type: "response.in_progress",
+            response: {
+              id: state.responseId,
+              object: "response",
+              created_at: state.created,
+              status: "in_progress"
+            }
+          });
+        }
+
+        // Handle reasoning_content (OpenAI native format)
+        if (delta.reasoning_content) {
+          startReasoning(controller, idx);
+          emitReasoningDelta(controller, delta.reasoning_content);
+        }
+
+        // Handle text content (may contain <think> tags)
+        if (delta.content) {
+          let content = delta.content;
+
+          if (content.includes("<think>")) {
+            state.inThinking = true;
+            content = content.replace("<think>", "");
+            startReasoning(controller, idx);
+          }
+
+          if (content.includes("</think>")) {
+            const parts = content.split("</think>");
+            const thinkPart = parts[0];
+            const textPart = parts.slice(1).join("</think>");
+            
+            if (thinkPart) emitReasoningDelta(controller, thinkPart);
+            closeReasoning(controller);
+            state.inThinking = false;
+            content = textPart;
+          }
+
+          if (state.inThinking && content) {
+            emitReasoningDelta(controller, content);
+            continue;
+          }
+
+          // Regular text content
+          if (content) {
+            if (!state.msgItemAdded[idx]) {
+              state.msgItemAdded[idx] = true;
+              const msgId = `msg_${state.responseId}_${idx}`;
+              
+              emit(controller, "response.output_item.added", {
+                type: "response.output_item.added",
+                output_index: idx,
+                item: { id: msgId, type: "message", content: [], role: "assistant" }
+              });
+            }
+
+            if (!state.msgContentAdded[idx]) {
+              state.msgContentAdded[idx] = true;
+              
+              emit(controller, "response.content_part.added", {
+                type: "response.content_part.added",
+                item_id: `msg_${state.responseId}_${idx}`,
+                output_index: idx,
+                content_index: 0,
+                part: { type: "output_text", annotations: [], logprobs: [], text: "" }
+              });
+            }
+
+            emit(controller, "response.output_text.delta", {
+              type: "response.output_text.delta",
+              item_id: `msg_${state.responseId}_${idx}`,
+              output_index: idx,
+              content_index: 0,
+              delta: content,
+              logprobs: []
+            });
+
+            if (!state.msgTextBuf[idx]) state.msgTextBuf[idx] = "";
+            state.msgTextBuf[idx] += content;
+          }
+        }
+
+        // Handle tool_calls
+        if (delta.tool_calls) {
+          closeMessage(controller, idx);
+
+          for (const tc of delta.tool_calls) {
+            const tcIdx = tc.index ?? 0;
+            const newCallId = tc.id;
+            const funcName = tc.function?.name;
+
+            if (funcName) state.funcNames[tcIdx] = funcName;
+
+            if (!state.funcCallIds[tcIdx] && newCallId) {
+              state.funcCallIds[tcIdx] = newCallId;
+              
+              emit(controller, "response.output_item.added", {
+                type: "response.output_item.added",
+                output_index: tcIdx,
+                item: {
+                  id: `fc_${newCallId}`,
+                  type: "function_call",
+                  arguments: "",
+                  call_id: newCallId,
+                  name: state.funcNames[tcIdx] || ""
+                }
+              });
+            }
+
+            if (!state.funcArgsBuf[tcIdx]) state.funcArgsBuf[tcIdx] = "";
+
+            if (tc.function?.arguments) {
+              const refCallId = state.funcCallIds[tcIdx] || newCallId;
+              if (refCallId) {
+                emit(controller, "response.function_call_arguments.delta", {
+                  type: "response.function_call_arguments.delta",
+                  item_id: `fc_${refCallId}`,
+                  output_index: tcIdx,
+                  delta: tc.function.arguments
+                });
+              }
+              state.funcArgsBuf[tcIdx] += tc.function.arguments;
+            }
+          }
+        }
+
+        // Handle finish_reason
+        if (choice.finish_reason) {
+          for (const i in state.msgItemAdded) closeMessage(controller, i);
+          closeReasoning(controller);
+          for (const i in state.funcCallIds) closeToolCall(controller, i);
+          sendCompleted(controller);
+        }
+      }
+    },
+
+    flush(controller) {
+      for (const i in state.msgItemAdded) closeMessage(controller, i);
+      closeReasoning(controller);
+      for (const i in state.funcCallIds) closeToolCall(controller, i);
+      sendCompleted(controller);
+
+      logger?.logOutput("data: [DONE]");
+      controller.enqueue(encoder.encode("data: [DONE]\n\n"));
+      logger?.flush();
+    }
+  });
+}
+

open-sse/translator/formats.js

@@ -0,0 +1,12 @@
+// Format identifiers
+export const FORMATS = {
+  OPENAI: "openai",
+  OPENAI_RESPONSES: "openai-responses",
+  OPENAI_RESPONSE: "openai-response",
+  CLAUDE: "claude",
+  GEMINI: "gemini",
+  GEMINI_CLI: "gemini-cli",
+  CODEX: "codex",
+  ANTIGRAVITY: "antigravity"
+};
+

open-sse/translator/from-openai/claude.js

@@ -0,0 +1,348 @@
+import { register } from "../index.js";
+import { FORMATS } from "../formats.js";
+
+// Create OpenAI chunk helper
+function createChunk(state, delta, finishReason = null) {
+  return {
+    id: `chatcmpl-${state.messageId}`,
+    object: "chat.completion.chunk",
+    created: Math.floor(Date.now() / 1000),
+    model: state.model,
+    choices: [{
+      index: 0,
+      delta,
+      finish_reason: finishReason
+    }]
+  };
+}
+
+// Convert Claude stream chunk to OpenAI format
+function claudeToOpenAIResponse(chunk, state) {
+  if (!chunk) return null;
+
+  const results = [];
+  const event = chunk.type;
+
+  switch (event) {
+    case "message_start": {
+      state.messageId = chunk.message?.id || `msg_${Date.now()}`;
+      state.model = chunk.message?.model;
+      state.toolCallIndex = 0; // Reset tool call counter for OpenAI format
+      console.log("🔍 ----------- toolCallIndex", state.toolCallIndex);
+      results.push(createChunk(state, { role: "assistant" }));
+      break;
+    }
+
+    case "content_block_start": {
+      const block = chunk.content_block;
+      if (block?.type === "text") {
+        state.textBlockStarted = true;
+      } else if (block?.type === "thinking") {
+        // console.log("🧠 Thinking block started");
+        state.inThinkingBlock = true;
+        state.currentBlockIndex = chunk.index;
+        results.push(createChunk(state, { content: "<think>" }));
+      } else if (block?.type === "tool_use") {
+        // OpenAI format: tool_calls index must be independent and start from 0
+        const toolCallIndex = state.toolCallIndex++;
+        const toolCall = {
+          index: toolCallIndex,
+          id: block.id,
+          type: "function",
+          function: {
+            name: block.name,
+            arguments: ""
+          }
+        };
+        // Map Claude content_block index to OpenAI tool_call index
+        state.toolCalls.set(chunk.index, toolCall);
+        results.push(createChunk(state, { tool_calls: [toolCall] }));
+      }
+      break;
+    }
+
+    case "content_block_delta": {
+      const delta = chunk.delta;
+      if (delta?.type === "text_delta" && delta.text) {
+        results.push(createChunk(state, { content: delta.text }));
+      } else if (delta?.type === "thinking_delta" && delta.thinking) {
+        // Stream thinking content
+        results.push(createChunk(state, { content: delta.thinking }));
+      } else if (delta?.type === "input_json_delta" && delta.partial_json) {
+        const toolCall = state.toolCalls.get(chunk.index);
+        if (toolCall) {
+          toolCall.function.arguments += delta.partial_json;
+          // Include both index and id for better client compatibility
+          results.push(createChunk(state, {
+            tool_calls: [{
+              index: toolCall.index,
+              id: toolCall.id,
+              function: { arguments: delta.partial_json }
+            }]
+          }));
+        }
+      }
+      break;
+    }
+
+    case "content_block_stop": {
+      if (state.inThinkingBlock && chunk.index === state.currentBlockIndex) {
+        // console.log("✅ Thinking block ended");
+        results.push(createChunk(state, { content: "</think>" }));
+        state.inThinkingBlock = false;
+      }
+      state.textBlockStarted = false;
+      state.thinkingBlockStarted = false;
+      break;
+    }
+
+    case "message_delta": {
+      if (chunk.delta?.stop_reason) {
+        state.finishReason = convertStopReason(chunk.delta.stop_reason);
+
+        // Send the final chunk with finish_reason immediately
+        results.push({
+          id: `chatcmpl-${state.messageId}`,
+          object: "chat.completion.chunk",
+          created: Math.floor(Date.now() / 1000),
+          model: state.model,
+          choices: [{
+            index: 0,
+            delta: {},
+            finish_reason: state.finishReason
+          }]
+        });
+        state.finishReasonSent = true;
+      }
+      // Usage is now extracted in stream.js extractUsage()
+      break;
+    }
+
+    case "message_stop": {
+      // CLIProxyAPI and OpenAI standard: message_stop should send the final chunk with finish_reason
+      // This ensures proper signaling to the client that the response is complete
+
+      // Only send a chunk if we haven't already sent the finish_reason in message_delta
+      // In some cases, finish_reason might not have been sent yet
+      if (!state.finishReasonSent) {
+        const finishReason = state.finishReason || (state.toolCalls?.size > 0 ? "tool_calls" : "stop");
+        results.push({
+          id: `chatcmpl-${state.messageId}`,
+          object: "chat.completion.chunk",
+          created: Math.floor(Date.now() / 1000),
+          model: state.model,
+          choices: [{
+            index: 0,
+            delta: {},
+            finish_reason: finishReason
+          }],
+          ...(state.usage && {
+            usage: {
+              prompt_tokens: state.usage.input_tokens || 0,
+              completion_tokens: state.usage.output_tokens || 0,
+              total_tokens: (state.usage.input_tokens || 0) + (state.usage.output_tokens || 0)
+            }
+          })
+        });
+        state.finishReasonSent = true;
+      }
+      break;
+    }
+  }
+
+  return results.length > 0 ? results : null;
+}
+
+// Helper: stop thinking block if started
+function stopThinkingBlock(state, results) {
+  if (!state.thinkingBlockStarted) return;
+  results.push({
+    type: "content_block_stop",
+    index: state.thinkingBlockIndex
+  });
+  state.thinkingBlockStarted = false;
+}
+
+// Helper: stop text block if started
+function stopTextBlock(state, results) {
+  if (!state.textBlockStarted || state.textBlockClosed) return;
+  state.textBlockClosed = true;
+  results.push({
+    type: "content_block_stop",
+    index: state.textBlockIndex
+  });
+  state.textBlockStarted = false;
+}
+
+// Convert OpenAI stream chunk to Claude format
+function openaiToClaudeResponse(chunk, state) {
+  if (!chunk || !chunk.choices?.[0]) return null;
+
+  const results = [];
+  const choice = chunk.choices[0];
+  const delta = choice.delta;
+
+  // First chunk - ALWAYS send message_start first
+  if (!state.messageStartSent) {
+    state.messageStartSent = true;
+    state.messageId = chunk.id?.replace("chatcmpl-", "") || `msg_${Date.now()}`;
+    if (!state.messageId || state.messageId === "chat" || state.messageId.length < 8) {
+      state.messageId = chunk.extend_fields?.requestId ||
+        chunk.extend_fields?.traceId ||
+        `msg_${Date.now()}`;
+    }
+    state.model = chunk.model || "unknown";
+    state.nextBlockIndex = 0;
+    results.push({
+      type: "message_start",
+      message: {
+        id: state.messageId,
+        type: "message",
+        role: "assistant",
+        model: state.model,
+        content: [],
+        stop_reason: null,
+        stop_sequence: null,
+        usage: { input_tokens: 0, output_tokens: 0 }
+      }
+    });
+  }
+
+  // Handle reasoning_content (thinking) - GLM, DeepSeek, etc.
+  const reasoningContent = delta?.reasoning_content || delta?.reasoning;
+  if (reasoningContent) {
+    // Stop text block before thinking
+    stopTextBlock(state, results);
+
+    // Start thinking block if needed
+    if (!state.thinkingBlockStarted) {
+      state.thinkingBlockIndex = state.nextBlockIndex++;
+      state.thinkingBlockStarted = true;
+      results.push({
+        type: "content_block_start",
+        index: state.thinkingBlockIndex,
+        content_block: { type: "thinking", thinking: "" }
+      });
+    }
+
+    // Send thinking delta
+    results.push({
+      type: "content_block_delta",
+      index: state.thinkingBlockIndex,
+      delta: { type: "thinking_delta", thinking: reasoningContent }
+    });
+  }
+
+  // Handle regular content
+  if (delta?.content) {
+    // Stop thinking block before text
+    stopThinkingBlock(state, results);
+
+    // Start text block if needed
+    if (!state.textBlockStarted) {
+      state.textBlockIndex = state.nextBlockIndex++;
+      state.textBlockStarted = true;
+      state.textBlockClosed = false;
+      results.push({
+        type: "content_block_start",
+        index: state.textBlockIndex,
+        content_block: { type: "text", text: "" }
+      });
+    }
+
+    // Send text delta
+    results.push({
+      type: "content_block_delta",
+      index: state.textBlockIndex,
+      delta: { type: "text_delta", text: delta.content }
+    });
+  }
+
+  // Tool calls
+  if (delta?.tool_calls) {
+    for (const tc of delta.tool_calls) {
+      const idx = tc.index ?? 0;
+
+      if (tc.id) {
+        // Stop thinking and text blocks before tool use
+        stopThinkingBlock(state, results);
+        stopTextBlock(state, results);
+
+        // New tool call
+        const toolBlockIndex = state.nextBlockIndex++;
+        state.toolCalls.set(idx, { id: tc.id, name: tc.function?.name || "", blockIndex: toolBlockIndex });
+        results.push({
+          type: "content_block_start",
+          index: toolBlockIndex,
+          content_block: {
+            type: "tool_use",
+            id: tc.id,
+            name: tc.function?.name || "",
+            input: {}
+          }
+        });
+      }
+
+      if (tc.function?.arguments) {
+        const toolInfo = state.toolCalls.get(idx);
+        if (toolInfo) {
+          results.push({
+            type: "content_block_delta",
+            index: toolInfo.blockIndex,
+            delta: { type: "input_json_delta", partial_json: tc.function.arguments }
+          });
+        }
+      }
+    }
+  }
+
+  // Finish
+  if (choice.finish_reason) {
+    // Stop all open blocks
+    stopThinkingBlock(state, results);
+    stopTextBlock(state, results);
+
+    // Close tool call blocks
+    for (const [, toolInfo] of state.toolCalls) {
+      results.push({
+        type: "content_block_stop",
+        index: toolInfo.blockIndex
+      });
+    }
+
+    results.push({
+      type: "message_delta",
+      delta: { stop_reason: convertFinishReason(choice.finish_reason) },
+      usage: { output_tokens: 0 }
+    });
+    results.push({ type: "message_stop" });
+  }
+
+  return results.length > 0 ? results : null;
+}
+
+// Convert Claude stop_reason to OpenAI finish_reason
+function convertStopReason(reason) {
+  switch (reason) {
+    case "end_turn": return "stop";
+    case "max_tokens": return "length";
+    case "tool_use": return "tool_calls";
+    case "stop_sequence": return "stop";
+    default: return "stop";
+  }
+}
+
+// Convert OpenAI finish_reason to Claude stop_reason
+function convertFinishReason(reason) {
+  switch (reason) {
+    case "stop": return "end_turn";
+    case "length": return "max_tokens";
+    case "tool_calls": return "tool_use";
+    default: return "end_turn";
+  }
+}
+
+// Register
+register(FORMATS.CLAUDE, FORMATS.OPENAI, null, claudeToOpenAIResponse);
+register(FORMATS.OPENAI, FORMATS.CLAUDE, null, openaiToClaudeResponse);
+

open-sse/translator/from-openai/gemini.js

@@ -0,0 +1,469 @@
+import { register } from "../index.js";
+import { FORMATS } from "../formats.js";
+import { DEFAULT_THINKING_GEMINI_SIGNATURE } from "../../config/defaultThinkingSignature.js";
+import {
+  UNSUPPORTED_SCHEMA_CONSTRAINTS,
+  DEFAULT_SAFETY_SETTINGS,
+  convertOpenAIContentToParts,
+  extractTextContent,
+  tryParseJSON,
+  generateRequestId,
+  generateSessionId,
+  generateProjectId,
+  cleanJSONSchemaForAntigravity
+} from "../helpers/geminiHelper.js";
+
+// ============================================
+// REQUEST TRANSLATORS: OpenAI -> Gemini/GeminiCLI/Antigravity
+// ============================================
+
+// Core: Convert OpenAI request to Gemini format (base for all variants)
+function openaiToGeminiBase(model, body, stream) {
+  const result = {
+    model: model,
+    contents: [],
+    generationConfig: {},
+    safetySettings: DEFAULT_SAFETY_SETTINGS
+  };
+
+  // Generation config
+  if (body.temperature !== undefined) {
+    result.generationConfig.temperature = body.temperature;
+  }
+  if (body.top_p !== undefined) {
+    result.generationConfig.topP = body.top_p;
+  }
+  if (body.top_k !== undefined) {
+    result.generationConfig.topK = body.top_k;
+  }
+  if (body.max_tokens !== undefined) {
+    result.generationConfig.maxOutputTokens = body.max_tokens;
+  }
+
+  // Build tool_call_id -> name map
+  const tcID2Name = {};
+  if (body.messages && Array.isArray(body.messages)) {
+    for (const msg of body.messages) {
+      if (msg.role === "assistant" && msg.tool_calls) {
+        for (const tc of msg.tool_calls) {
+          if (tc.type === "function" && tc.id && tc.function?.name) {
+            tcID2Name[tc.id] = tc.function.name;
+          }
+        }
+      }
+    }
+  }
+
+  // Build tool responses cache
+  const toolResponses = {};
+  if (body.messages && Array.isArray(body.messages)) {
+    for (const msg of body.messages) {
+      if (msg.role === "tool" && msg.tool_call_id) {
+        toolResponses[msg.tool_call_id] = msg.content;
+      }
+    }
+  }
+
+  // Convert messages
+  if (body.messages && Array.isArray(body.messages)) {
+    for (let i = 0; i < body.messages.length; i++) {
+      const msg = body.messages[i];
+      const role = msg.role;
+      const content = msg.content;
+
+      if (role === "system" && body.messages.length > 1) {
+        result.systemInstruction = {
+          role: "user",
+          parts: [{ text: typeof content === "string" ? content : extractTextContent(content) }]
+        };
+      } else if (role === "user" || (role === "system" && body.messages.length === 1)) {
+        const parts = convertOpenAIContentToParts(content);
+        if (parts.length > 0) {
+          result.contents.push({ role: "user", parts });
+        }
+      } else if (role === "assistant") {
+        const parts = [];
+        
+        if (content) {
+          const text = typeof content === "string" ? content : extractTextContent(content);
+          if (text) {
+            parts.push({ text });
+          }
+        }
+
+        if (msg.tool_calls && Array.isArray(msg.tool_calls)) {
+          const toolCallIds = [];
+          for (const tc of msg.tool_calls) {
+            if (tc.type !== "function") continue;
+            
+            const args = tryParseJSON(tc.function?.arguments || "{}");
+            parts.push({
+              thoughtSignature: DEFAULT_THINKING_GEMINI_SIGNATURE,
+              functionCall: {
+                id: tc.id,
+                name: tc.function.name,
+                args: args
+              }
+            });
+            toolCallIds.push(tc.id);
+          }
+
+          if (parts.length > 0) {
+            result.contents.push({ role: "model", parts });
+          }
+
+          // Append function responses - extract name from tool_call_id format "ToolName-timestamp-index"
+          const toolParts = [];
+          for (const fid of toolCallIds) {
+            // Try to get name from tcID2Name map first, then extract from id format
+            let name = tcID2Name[fid];
+            if (!name) {
+              // Extract name from id format: "ToolName-timestamp-index"
+              const idParts = fid.split("-");
+              if (idParts.length > 2) {
+                name = idParts.slice(0, -2).join("-");
+              } else {
+                name = fid;
+              }
+            }
+            
+              let resp = toolResponses[fid] || "{}";
+              let parsedResp = tryParseJSON(resp);
+              if (parsedResp === null) {
+                parsedResp = { result: resp };
+              } else if (typeof parsedResp !== "object") {
+                parsedResp = { result: parsedResp };
+              }
+              
+              toolParts.push({
+                functionResponse: {
+                  id: fid,
+                  name: name,
+                  response: { result: parsedResp }
+                }
+              });
+          }
+          if (toolParts.length > 0) {
+            result.contents.push({ role: "user", parts: toolParts });
+          }
+        } else if (parts.length > 0) {
+          result.contents.push({ role: "model", parts });
+        }
+      }
+    }
+  }
+
+  // Convert tools
+  if (body.tools && Array.isArray(body.tools) && body.tools.length > 0) {
+    const functionDeclarations = [];
+    for (const t of body.tools) {
+      if (t.type === "function" && t.function) {
+        const fn = t.function;
+        functionDeclarations.push({
+          name: fn.name,
+          description: fn.description || "",
+          parameters: fn.parameters || { type: "object", properties: {} }
+        });
+      }
+    }
+    
+    if (functionDeclarations.length > 0) {
+      result.tools = [{ functionDeclarations }];
+    }
+  }
+
+  return result;
+}
+
+// OpenAI -> Gemini (standard API)
+function openaiToGemini(model, body, stream) {
+  return openaiToGeminiBase(model, body, stream);
+}
+
+// OpenAI -> Gemini CLI (Cloud Code Assist)
+function openaiToGeminiCLI(model, body, stream) {
+  const gemini = openaiToGeminiBase(model, body, stream);
+  const isClaude = model.toLowerCase().includes("claude");
+  
+  // Add thinking config for CLI
+  if (body.reasoning_effort) {
+    const budgetMap = { low: 1024, medium: 8192, high: 32768 };
+    const budget = budgetMap[body.reasoning_effort] || 8192;
+    gemini.generationConfig.thinkingConfig = {
+      thinkingBudget: budget,
+      include_thoughts: true
+    };
+  }
+
+  // Thinking config from Claude format
+  if (body.thinking?.type === "enabled" && body.thinking.budget_tokens) {
+    gemini.generationConfig.thinkingConfig = {
+      thinkingBudget: body.thinking.budget_tokens,
+      include_thoughts: true
+    };
+  }
+
+  // Clean schema for tools
+  // Claude models: use "parameters" (backend converts parametersJsonSchema -> parameters)
+  // Gemini native: use "parametersJsonSchema" (backend expects this field)
+  if (gemini.tools?.[0]?.functionDeclarations) {
+    for (const fn of gemini.tools[0].functionDeclarations) {
+      if (fn.parameters) {
+        const cleanedSchema = cleanJSONSchemaForAntigravity(fn.parameters);
+        if (isClaude) {
+          fn.parameters = cleanedSchema;
+        } else {
+          fn.parametersJsonSchema = cleanedSchema;
+          delete fn.parameters;
+        }
+      }
+    }
+  }
+
+  return gemini;
+}
+
+// Wrap Gemini CLI format in Cloud Code wrapper
+function wrapInCloudCodeEnvelope(model, geminiCLI, credentials = null) {
+  // Use real project ID if available, otherwise generate random
+  const projectId = credentials?.projectId || generateProjectId();
+  
+  return {
+    project: projectId,
+    model: model,
+    userAgent: "gemini-cli",
+    requestId: generateRequestId(),
+    request: {
+      sessionId: generateSessionId(),
+      contents: geminiCLI.contents,
+      systemInstruction: geminiCLI.systemInstruction,
+      generationConfig: geminiCLI.generationConfig,
+      safetySettings: geminiCLI.safetySettings,
+      tools: geminiCLI.tools,
+    }
+  };
+}
+
+// OpenAI -> Antigravity (Sandbox Cloud Code with wrapper)
+function openaiToAntigravity(model, body, stream, credentials = null) {
+  const geminiCLI = openaiToGeminiCLI(model, body, stream);
+  return wrapInCloudCodeEnvelope(model, geminiCLI, credentials);
+}
+
+// ============================================
+// RESPONSE TRANSLATORS: Gemini/GeminiCLI/Antigravity -> OpenAI
+// ============================================
+
+// Core: Convert Gemini response chunk to OpenAI format
+function geminiToOpenAIResponse(chunk, state) {
+  if (!chunk) return null;
+  
+  // Handle Antigravity wrapper
+  const response = chunk.response || chunk;
+  if (!response || !response.candidates?.[0]) return null;
+
+  const results = [];
+  const candidate = response.candidates[0];
+  const content = candidate.content;
+
+  // Initialize state
+  if (!state.messageId) {
+    state.messageId = response.responseId || `msg_${Date.now()}`;
+    state.model = response.modelVersion || "gemini";
+    state.functionIndex = 0;
+    results.push({
+      id: `chatcmpl-${state.messageId}`,
+      object: "chat.completion.chunk",
+      created: Math.floor(Date.now() / 1000),
+      model: state.model,
+      choices: [{
+        index: 0,
+        delta: { role: "assistant" },
+        finish_reason: null
+      }]
+    });
+  }
+
+  // Process parts
+  if (content?.parts) {
+    for (const part of content.parts) {
+      const hasThoughtSig = part.thoughtSignature || part.thought_signature;
+      const isThought = part.thought === true;
+      
+      // Handle thought signature (thinking mode)
+      if (hasThoughtSig) {
+        const hasTextContent = part.text !== undefined && part.text !== "";
+        const hasFunctionCall = !!part.functionCall;
+        // If there's text with thoughtSignature
+        if (hasTextContent) {
+        results.push({
+          id: `chatcmpl-${state.messageId}`,
+          object: "chat.completion.chunk",
+          created: Math.floor(Date.now() / 1000),
+          model: state.model,
+          choices: [{
+            index: 0,
+            delta: isThought 
+              ? { reasoning_content: part.text }
+              : { content: part.text },
+              finish_reason: null
+            }]
+          });
+        }
+        
+        // Process functionCall if exists, then skip to next part
+        if (hasFunctionCall) {
+          const fcName = part.functionCall.name;
+          const fcArgs = part.functionCall.args || {};
+          const toolCallIndex = state.functionIndex++;
+          
+          const toolCall = {
+            id: `${fcName}-${Date.now()}-${toolCallIndex}`,
+            index: toolCallIndex,
+            type: "function",
+            function: {
+              name: fcName,
+              arguments: JSON.stringify(fcArgs)
+            }
+          };
+          
+          state.toolCalls.set(toolCallIndex, toolCall);
+          
+          results.push({
+            id: `chatcmpl-${state.messageId}`,
+            object: "chat.completion.chunk",
+            created: Math.floor(Date.now() / 1000),
+            model: state.model,
+            choices: [{
+              index: 0,
+              delta: { tool_calls: [toolCall] },
+              finish_reason: null
+            }]
+          });
+        }
+        continue;
+      }
+
+      // Text content (non-thinking) - skip empty text
+      if (part.text !== undefined && part.text !== "") {
+        results.push({
+          id: `chatcmpl-${state.messageId}`,
+          object: "chat.completion.chunk",
+          created: Math.floor(Date.now() / 1000),
+          model: state.model,
+          choices: [{
+            index: 0,
+            delta: { content: part.text },
+            finish_reason: null
+          }]
+        });
+      }
+
+      // Function call
+      if (part.functionCall) {
+        const fcName = part.functionCall.name;
+        const fcArgs = part.functionCall.args || {};
+        const toolCallIndex = state.functionIndex++;
+        
+        const toolCall = {
+          id: `${fcName}-${Date.now()}-${toolCallIndex}`,
+          index: toolCallIndex,
+          type: "function",
+          function: {
+            name: fcName,
+            arguments: JSON.stringify(fcArgs)
+          }
+        };
+        
+        state.toolCalls.set(toolCallIndex, toolCall);
+        
+        results.push({
+          id: `chatcmpl-${state.messageId}`,
+          object: "chat.completion.chunk",
+          created: Math.floor(Date.now() / 1000),
+          model: state.model,
+          choices: [{
+            index: 0,
+            delta: { tool_calls: [toolCall] },
+            finish_reason: null
+          }]
+        });
+      }
+
+      // Inline data (images)
+      const inlineData = part.inlineData || part.inline_data;
+      if (inlineData?.data) {
+        const mimeType = inlineData.mimeType || inlineData.mime_type || "image/png";
+        results.push({
+          id: `chatcmpl-${state.messageId}`,
+          object: "chat.completion.chunk",
+          created: Math.floor(Date.now() / 1000),
+          model: state.model,
+          choices: [{
+            index: 0,
+            delta: {
+              images: [{
+                type: "image_url",
+                image_url: { url: `data:${mimeType};base64,${inlineData.data}` }
+              }]
+            },
+            finish_reason: null
+          }]
+        });
+      }
+    }
+  }
+
+  // Finish reason
+  if (candidate.finishReason) {
+    let finishReason = candidate.finishReason.toLowerCase();
+    if (finishReason === "stop" && state.toolCalls.size > 0) {
+      finishReason = "tool_calls";
+    }
+    
+    results.push({
+      id: `chatcmpl-${state.messageId}`,
+      object: "chat.completion.chunk",
+      created: Math.floor(Date.now() / 1000),
+      model: state.model,
+      choices: [{
+        index: 0,
+        delta: {},
+        finish_reason: finishReason
+      }]
+    });
+    state.finishReason = finishReason;
+  }
+
+  // Usage metadata
+  const usage = response.usageMetadata || chunk.usageMetadata;
+  if (usage) {
+    const promptTokens = (usage.promptTokenCount || 0) + (usage.thoughtsTokenCount || 0);
+    state.usage = {
+      prompt_tokens: promptTokens,
+      completion_tokens: usage.candidatesTokenCount || 0,
+      total_tokens: usage.totalTokenCount || 0
+    };
+    if (usage.thoughtsTokenCount > 0) {
+      state.usage.completion_tokens_details = {
+        reasoning_tokens: usage.thoughtsTokenCount
+      };
+    }
+  }
+
+  return results.length > 0 ? results : null;
+}
+
+// ============================================
+// REGISTER ALL TRANSLATORS
+// ============================================
+
+// Request: OpenAI -> Gemini variants
+register(FORMATS.OPENAI, FORMATS.GEMINI, openaiToGemini, null);
+register(FORMATS.OPENAI, FORMATS.GEMINI_CLI, (model, body, stream, credentials) => wrapInCloudCodeEnvelope(model, openaiToGeminiCLI(model, body, stream), credentials), null);
+register(FORMATS.OPENAI, FORMATS.ANTIGRAVITY, openaiToAntigravity, null);
+
+// Response: Gemini variants -> OpenAI (all use same handler)
+register(FORMATS.GEMINI, FORMATS.OPENAI, null, geminiToOpenAIResponse);
+register(FORMATS.GEMINI_CLI, FORMATS.OPENAI, null, geminiToOpenAIResponse);
+register(FORMATS.ANTIGRAVITY, FORMATS.OPENAI, null, geminiToOpenAIResponse);

open-sse/translator/from-openai/openai-responses.js

@@ -0,0 +1,361 @@
+/**
+ * Translator: OpenAI Chat Completions → OpenAI Responses API (response)
+ * Converts streaming chunks from Chat Completions to Responses API events
+ */
+import { register } from "../index.js";
+import { FORMATS } from "../formats.js";
+
+/**
+ * Translate OpenAI chunk to Responses API events
+ * @returns {Array} Array of events with { event, data } structure
+ */
+function translateResponse(chunk, state) {
+  if (!chunk) {
+    // Flush remaining events
+    return flushEvents(state);
+  }
+  
+  if (!chunk.choices?.length) return [];
+  
+  const events = [];
+  const nextSeq = () => ++state.seq;
+  
+  const emit = (eventType, data) => {
+    data.sequence_number = nextSeq();
+    events.push({ event: eventType, data });
+  };
+
+  const choice = chunk.choices[0];
+  const idx = choice.index || 0;
+  const delta = choice.delta || {};
+
+  // Emit initial events
+  if (!state.started) {
+    state.started = true;
+    state.responseId = chunk.id ? `resp_${chunk.id}` : state.responseId;
+    
+    emit("response.created", {
+      type: "response.created",
+      response: {
+        id: state.responseId,
+        object: "response",
+        created_at: state.created,
+        status: "in_progress",
+        background: false,
+        error: null,
+        output: []
+      }
+    });
+
+    emit("response.in_progress", {
+      type: "response.in_progress",
+      response: {
+        id: state.responseId,
+        object: "response",
+        created_at: state.created,
+        status: "in_progress"
+      }
+    });
+  }
+
+  // Handle reasoning_content
+  if (delta.reasoning_content) {
+    startReasoning(state, emit, idx);
+    emitReasoningDelta(state, emit, delta.reasoning_content);
+  }
+
+  // Handle text content
+  if (delta.content) {
+    let content = delta.content;
+
+    if (content.includes("<think>")) {
+      state.inThinking = true;
+      content = content.replace("<think>", "");
+      startReasoning(state, emit, idx);
+    }
+
+    if (content.includes("</think>")) {
+      const parts = content.split("</think>");
+      const thinkPart = parts[0];
+      const textPart = parts.slice(1).join("</think>");
+      if (thinkPart) emitReasoningDelta(state, emit, thinkPart);
+      closeReasoning(state, emit);
+      state.inThinking = false;
+      content = textPart;
+    }
+
+    if (state.inThinking && content) {
+      emitReasoningDelta(state, emit, content);
+      return events;
+    }
+
+    if (content) {
+      emitTextContent(state, emit, idx, content);
+    }
+  }
+
+  // Handle tool_calls
+  if (delta.tool_calls) {
+    closeMessage(state, emit, idx);
+    for (const tc of delta.tool_calls) {
+      emitToolCall(state, emit, tc);
+    }
+  }
+
+  // Handle finish_reason
+  if (choice.finish_reason) {
+    for (const i in state.msgItemAdded) closeMessage(state, emit, i);
+    closeReasoning(state, emit);
+    for (const i in state.funcCallIds) closeToolCall(state, emit, i);
+    sendCompleted(state, emit);
+  }
+
+  return events;
+}
+
+// Helper functions
+function startReasoning(state, emit, idx) {
+  if (!state.reasoningId) {
+    state.reasoningId = `rs_${state.responseId}_${idx}`;
+    state.reasoningIndex = idx;
+    
+    emit("response.output_item.added", {
+      type: "response.output_item.added",
+      output_index: idx,
+      item: { id: state.reasoningId, type: "reasoning", summary: [] }
+    });
+
+    emit("response.reasoning_summary_part.added", {
+      type: "response.reasoning_summary_part.added",
+      item_id: state.reasoningId,
+      output_index: idx,
+      summary_index: 0,
+      part: { type: "summary_text", text: "" }
+    });
+    state.reasoningPartAdded = true;
+  }
+}
+
+function emitReasoningDelta(state, emit, text) {
+  if (!text) return;
+  state.reasoningBuf += text;
+  emit("response.reasoning_summary_text.delta", {
+    type: "response.reasoning_summary_text.delta",
+    item_id: state.reasoningId,
+    output_index: state.reasoningIndex,
+    summary_index: 0,
+    delta: text
+  });
+}
+
+function closeReasoning(state, emit) {
+  if (state.reasoningId && !state.reasoningDone) {
+    state.reasoningDone = true;
+    
+    emit("response.reasoning_summary_text.done", {
+      type: "response.reasoning_summary_text.done",
+      item_id: state.reasoningId,
+      output_index: state.reasoningIndex,
+      summary_index: 0,
+      text: state.reasoningBuf
+    });
+
+    emit("response.reasoning_summary_part.done", {
+      type: "response.reasoning_summary_part.done",
+      item_id: state.reasoningId,
+      output_index: state.reasoningIndex,
+      summary_index: 0,
+      part: { type: "summary_text", text: state.reasoningBuf }
+    });
+
+    emit("response.output_item.done", {
+      type: "response.output_item.done",
+      output_index: state.reasoningIndex,
+      item: {
+        id: state.reasoningId,
+        type: "reasoning",
+        summary: [{ type: "summary_text", text: state.reasoningBuf }]
+      }
+    });
+  }
+}
+
+function emitTextContent(state, emit, idx, content) {
+  if (!state.msgItemAdded[idx]) {
+    state.msgItemAdded[idx] = true;
+    const msgId = `msg_${state.responseId}_${idx}`;
+    
+    emit("response.output_item.added", {
+      type: "response.output_item.added",
+      output_index: idx,
+      item: { id: msgId, type: "message", content: [], role: "assistant" }
+    });
+  }
+
+  if (!state.msgContentAdded[idx]) {
+    state.msgContentAdded[idx] = true;
+    
+    emit("response.content_part.added", {
+      type: "response.content_part.added",
+      item_id: `msg_${state.responseId}_${idx}`,
+      output_index: idx,
+      content_index: 0,
+      part: { type: "output_text", annotations: [], logprobs: [], text: "" }
+    });
+  }
+
+  emit("response.output_text.delta", {
+    type: "response.output_text.delta",
+    item_id: `msg_${state.responseId}_${idx}`,
+    output_index: idx,
+    content_index: 0,
+    delta: content,
+    logprobs: []
+  });
+
+  if (!state.msgTextBuf[idx]) state.msgTextBuf[idx] = "";
+  state.msgTextBuf[idx] += content;
+}
+
+function closeMessage(state, emit, idx) {
+  if (state.msgItemAdded[idx] && !state.msgItemDone[idx]) {
+    state.msgItemDone[idx] = true;
+    const fullText = state.msgTextBuf[idx] || "";
+    const msgId = `msg_${state.responseId}_${idx}`;
+
+    emit("response.output_text.done", {
+      type: "response.output_text.done",
+      item_id: msgId,
+      output_index: parseInt(idx),
+      content_index: 0,
+      text: fullText,
+      logprobs: []
+    });
+
+    emit("response.content_part.done", {
+      type: "response.content_part.done",
+      item_id: msgId,
+      output_index: parseInt(idx),
+      content_index: 0,
+      part: { type: "output_text", annotations: [], logprobs: [], text: fullText }
+    });
+
+    emit("response.output_item.done", {
+      type: "response.output_item.done",
+      output_index: parseInt(idx),
+      item: {
+        id: msgId,
+        type: "message",
+        content: [{ type: "output_text", annotations: [], logprobs: [], text: fullText }],
+        role: "assistant"
+      }
+    });
+  }
+}
+
+function emitToolCall(state, emit, tc) {
+  const tcIdx = tc.index ?? 0;
+  const newCallId = tc.id;
+  const funcName = tc.function?.name;
+
+  if (funcName) state.funcNames[tcIdx] = funcName;
+
+  if (!state.funcCallIds[tcIdx] && newCallId) {
+    state.funcCallIds[tcIdx] = newCallId;
+    
+    emit("response.output_item.added", {
+      type: "response.output_item.added",
+      output_index: tcIdx,
+      item: {
+        id: `fc_${newCallId}`,
+        type: "function_call",
+        arguments: "",
+        call_id: newCallId,
+        name: state.funcNames[tcIdx] || ""
+      }
+    });
+  }
+
+  if (!state.funcArgsBuf[tcIdx]) state.funcArgsBuf[tcIdx] = "";
+
+  if (tc.function?.arguments) {
+    const refCallId = state.funcCallIds[tcIdx] || newCallId;
+    if (refCallId) {
+      emit("response.function_call_arguments.delta", {
+        type: "response.function_call_arguments.delta",
+        item_id: `fc_${refCallId}`,
+        output_index: tcIdx,
+        delta: tc.function.arguments
+      });
+    }
+    state.funcArgsBuf[tcIdx] += tc.function.arguments;
+  }
+}
+
+function closeToolCall(state, emit, idx) {
+  const callId = state.funcCallIds[idx];
+  if (callId && !state.funcItemDone[idx]) {
+    const args = state.funcArgsBuf[idx] || "{}";
+    
+    emit("response.function_call_arguments.done", {
+      type: "response.function_call_arguments.done",
+      item_id: `fc_${callId}`,
+      output_index: parseInt(idx),
+      arguments: args
+    });
+
+    emit("response.output_item.done", {
+      type: "response.output_item.done",
+      output_index: parseInt(idx),
+      item: {
+        id: `fc_${callId}`,
+        type: "function_call",
+        arguments: args,
+        call_id: callId,
+        name: state.funcNames[idx] || ""
+      }
+    });
+
+    state.funcItemDone[idx] = true;
+    state.funcArgsDone[idx] = true;
+  }
+}
+
+function sendCompleted(state, emit) {
+  if (!state.completedSent) {
+    state.completedSent = true;
+    emit("response.completed", {
+      type: "response.completed",
+      response: {
+        id: state.responseId,
+        object: "response",
+        created_at: state.created,
+        status: "completed",
+        background: false,
+        error: null
+      }
+    });
+  }
+}
+
+function flushEvents(state) {
+  if (state.completedSent) return [];
+  
+  const events = [];
+  const nextSeq = () => ++state.seq;
+  const emit = (eventType, data) => {
+    data.sequence_number = nextSeq();
+    events.push({ event: eventType, data });
+  };
+
+  for (const i in state.msgItemAdded) closeMessage(state, emit, i);
+  closeReasoning(state, emit);
+  for (const i in state.funcCallIds) closeToolCall(state, emit, i);
+  sendCompleted(state, emit);
+  
+  return events;
+}
+
+// Register translator
+register(FORMATS.OPENAI, FORMATS.OPENAI_RESPONSES, null, translateResponse);
+

open-sse/translator/helpers/claudeHelper.js

@@ -0,0 +1,179 @@
+// Claude helper functions for translator
+import { DEFAULT_THINKING_CLAUDE_SIGNATURE } from "../../config/defaultThinkingSignature.js";
+
+// Check if message has valid non-empty content
+export function hasValidContent(msg) {
+  if (typeof msg.content === "string" && msg.content.trim()) return true;
+  if (Array.isArray(msg.content)) {
+    return msg.content.some(block =>
+      (block.type === "text" && block.text?.trim()) ||
+      block.type === "tool_use" ||
+      block.type === "tool_result"
+    );
+  }
+  return false;
+}
+
+// Fix tool_use/tool_result ordering for Claude API
+// 1. Assistant message with tool_use: remove text AFTER tool_use (Claude doesn't allow)
+// 2. Merge consecutive same-role messages
+export function fixToolUseOrdering(messages) {
+  if (messages.length <= 1) return messages;
+  
+  // Pass 1: Fix assistant messages with tool_use - remove text after tool_use
+  for (const msg of messages) {
+    if (msg.role === "assistant" && Array.isArray(msg.content)) {
+      const hasToolUse = msg.content.some(b => b.type === "tool_use");
+      if (hasToolUse) {
+        // Keep only: thinking blocks + tool_use blocks (remove text blocks after tool_use)
+        const newContent = [];
+        let foundToolUse = false;
+        
+        for (const block of msg.content) {
+          if (block.type === "tool_use") {
+            foundToolUse = true;
+            newContent.push(block);
+          } else if (block.type === "thinking" || block.type === "redacted_thinking") {
+            newContent.push(block);
+          } else if (!foundToolUse) {
+            // Keep text blocks BEFORE tool_use
+            newContent.push(block);
+          }
+          // Skip text blocks AFTER tool_use
+        }
+        
+        msg.content = newContent;
+      }
+    }
+  }
+  
+  // Pass 2: Merge consecutive same-role messages
+  const merged = [];
+  
+  for (const msg of messages) {
+    const last = merged[merged.length - 1];
+    
+    if (last && last.role === msg.role) {
+      // Merge content arrays
+      const lastContent = Array.isArray(last.content) ? last.content : [{ type: "text", text: last.content }];
+      const msgContent = Array.isArray(msg.content) ? msg.content : [{ type: "text", text: msg.content }];
+      
+      // Put tool_result first, then other content
+      const toolResults = [...lastContent.filter(b => b.type === "tool_result"), ...msgContent.filter(b => b.type === "tool_result")];
+      const otherContent = [...lastContent.filter(b => b.type !== "tool_result"), ...msgContent.filter(b => b.type !== "tool_result")];
+      
+      last.content = [...toolResults, ...otherContent];
+    } else {
+      // Ensure content is array
+      const content = Array.isArray(msg.content) ? msg.content : [{ type: "text", text: msg.content }];
+      merged.push({ role: msg.role, content: [...content] });
+    }
+  }
+  
+  return merged;
+}
+
+// Prepare request for Claude format endpoints
+// - Cleanup cache_control
+// - Filter empty messages
+// - Add thinking block for Anthropic endpoint (provider === "claude")
+// - Fix tool_use/tool_result ordering
+export function prepareClaudeRequest(body, provider = null) {
+  // 1. System: remove all cache_control, add only to last block with ttl 1h
+  if (body.system && Array.isArray(body.system)) {
+    body.system = body.system.map((block, i) => {
+      const { cache_control, ...rest } = block;
+      if (i === body.system.length - 1) {
+        return { ...rest, cache_control: { type: "ephemeral", ttl: "1h" } };
+      }
+      return rest;
+    });
+  }
+
+  // 2. Messages: process in optimized passes
+  if (body.messages && Array.isArray(body.messages)) {
+    const len = body.messages.length;
+    let filtered = [];
+
+    // Pass 1: remove cache_control + filter empty messages
+    for (let i = 0; i < len; i++) {
+      const msg = body.messages[i];
+      
+      // Remove cache_control from content blocks
+      if (Array.isArray(msg.content)) {
+        for (const block of msg.content) {
+          delete block.cache_control;
+        }
+      }
+
+      // Keep final assistant even if empty, otherwise check valid content
+      const isFinalAssistant = i === len - 1 && msg.role === "assistant";
+      if (isFinalAssistant || hasValidContent(msg)) {
+        filtered.push(msg);
+      }
+    }
+
+    // Pass 1.5: Fix tool_use/tool_result ordering
+    // Each tool_use must have tool_result in the NEXT message (not same message with other content)
+    filtered = fixToolUseOrdering(filtered);
+
+    body.messages = filtered;
+
+    // Check if thinking is enabled AND last message is from user
+    const lastMessage = filtered[filtered.length - 1];
+    const lastMessageIsUser = lastMessage?.role === "user";
+    const thinkingEnabled = body.thinking?.type === "enabled" && lastMessageIsUser;
+
+    // Pass 2 (reverse): add cache_control to last assistant + handle thinking for Anthropic
+    let lastAssistantProcessed = false;
+    for (let i = filtered.length - 1; i >= 0; i--) {
+      const msg = filtered[i];
+      
+      if (msg.role === "assistant" && Array.isArray(msg.content)) {
+        // Add cache_control to last block of first (from end) assistant with content
+        if (!lastAssistantProcessed && msg.content.length > 0) {
+          msg.content[msg.content.length - 1].cache_control = { type: "ephemeral" };
+          lastAssistantProcessed = true;
+        }
+
+        // Handle thinking blocks for Anthropic endpoint only
+        if (provider === "claude") {
+          let hasToolUse = false;
+          let hasThinking = false;
+          
+          // Always replace signature for all thinking blocks
+          for (const block of msg.content) {
+            if (block.type === "thinking" || block.type === "redacted_thinking") {
+              block.signature = DEFAULT_THINKING_CLAUDE_SIGNATURE;
+              hasThinking = true;
+            }
+            if (block.type === "tool_use") hasToolUse = true;
+          }
+
+          // Add thinking block if thinking enabled + has tool_use but no thinking
+          if (thinkingEnabled && !hasThinking && hasToolUse) {
+            msg.content.unshift({
+              type: "thinking",
+              thinking: ".",
+              signature: DEFAULT_THINKING_CLAUDE_SIGNATURE
+            });
+          }
+        }
+      }
+    }
+  }
+
+  // 3. Tools: remove all cache_control, add only to last tool with ttl 1h
+  if (body.tools && Array.isArray(body.tools)) {
+    body.tools = body.tools.map((tool, i) => {
+      const { cache_control, ...rest } = tool;
+      if (i === body.tools.length - 1) {
+        return { ...rest, cache_control: { type: "ephemeral", ttl: "1h" } };
+      }
+      return rest;
+    });
+  }
+
+  return body;
+}
+

open-sse/translator/helpers/geminiHelper.js

@@ -0,0 +1,131 @@
+// Gemini helper functions for translator
+
+// Unsupported JSON Schema constraints that should be removed for Antigravity
+export const UNSUPPORTED_SCHEMA_CONSTRAINTS = [
+  "minLength", "maxLength", "exclusiveMinimum", "exclusiveMaximum",
+  "pattern", "minItems", "maxItems", "format",
+  "default", "examples", "$schema", "const"
+];
+
+// Default safety settings
+export const DEFAULT_SAFETY_SETTINGS = [
+  { category: "HARM_CATEGORY_HATE_SPEECH", threshold: "OFF" },
+  { category: "HARM_CATEGORY_DANGEROUS_CONTENT", threshold: "OFF" },
+  { category: "HARM_CATEGORY_SEXUALLY_EXPLICIT", threshold: "OFF" },
+  { category: "HARM_CATEGORY_HARASSMENT", threshold: "OFF" },
+  { category: "HARM_CATEGORY_CIVIC_INTEGRITY", threshold: "OFF" }
+];
+
+// Convert OpenAI content to Gemini parts
+export function convertOpenAIContentToParts(content) {
+  const parts = [];
+  
+  if (typeof content === "string") {
+    parts.push({ text: content });
+  } else if (Array.isArray(content)) {
+    for (const item of content) {
+      if (item.type === "text") {
+        parts.push({ text: item.text });
+      } else if (item.type === "image_url" && item.image_url?.url?.startsWith("data:")) {
+        const match = item.image_url.url.match(/^data:([^;]+);base64,(.+)$/);
+        if (match) {
+          parts.push({
+            inlineData: { mime_type: match[1], data: match[2] }
+          });
+        }
+      }
+    }
+  }
+  
+  return parts;
+}
+
+// Extract text content from OpenAI content
+export function extractTextContent(content) {
+  if (typeof content === "string") return content;
+  if (Array.isArray(content)) {
+    return content.filter(c => c.type === "text").map(c => c.text).join("");
+  }
+  return "";
+}
+
+// Try parse JSON safely
+export function tryParseJSON(str) {
+  if (typeof str !== "string") return str;
+  try {
+    return JSON.parse(str);
+  } catch {
+    return null;
+  }
+}
+
+// Generate request ID
+export function generateRequestId() {
+  return `agent-${crypto.randomUUID()}`;
+}
+
+// Generate session ID
+export function generateSessionId() {
+  return `-${Math.floor(Math.random() * 9000000000000000000)}`;
+}
+
+// Generate project ID
+export function generateProjectId() {
+  const adjectives = ["useful", "bright", "swift", "calm", "bold"];
+  const nouns = ["fuze", "wave", "spark", "flow", "core"];
+  const adj = adjectives[Math.floor(Math.random() * adjectives.length)];
+  const noun = nouns[Math.floor(Math.random() * nouns.length)];
+  return `${adj}-${noun}-${crypto.randomUUID().slice(0, 5)}`;
+}
+
+// Clean JSON Schema for Antigravity API compatibility - removes unsupported keywords recursively
+export function cleanJSONSchemaForAntigravity(schema) {
+  if (!schema || typeof schema !== "object") return schema;
+  
+  const cleaned = Array.isArray(schema) ? [] : {};
+  
+  for (const [key, value] of Object.entries(schema)) {
+    if (UNSUPPORTED_SCHEMA_CONSTRAINTS.includes(key)) continue;
+    
+    // Handle type array like ["string", "null"] - Gemini only supports single type
+    if (key === "type" && Array.isArray(value)) {
+      const nonNullType = value.find(t => t !== "null") || "string";
+      cleaned[key] = nonNullType;
+      continue;
+    }
+    
+    if (value && typeof value === "object") {
+      cleaned[key] = cleanJSONSchemaForAntigravity(value);
+    } else {
+      cleaned[key] = value;
+    }
+  }
+  
+  // Cleanup required fields - only keep fields that exist in properties
+  if (cleaned.required && Array.isArray(cleaned.required) && cleaned.properties) {
+    const validRequired = cleaned.required.filter(field => 
+      Object.prototype.hasOwnProperty.call(cleaned.properties, field)
+    );
+    if (validRequired.length === 0) {
+      delete cleaned.required;
+    } else {
+      cleaned.required = validRequired;
+    }
+  }
+  
+  // Add placeholder for empty object schemas (Antigravity requirement)
+  if (cleaned.type === "object") {
+    if (!cleaned.properties || Object.keys(cleaned.properties).length === 0) {
+      cleaned.properties = {
+        reason: {
+          type: "string",
+          description: "Brief explanation of why you are calling this tool"
+        }
+      };
+      cleaned.required = ["reason"];
+    }
+  }
+  
+  return cleaned;
+}
+

open-sse/translator/helpers/maxTokensHelper.js

@@ -0,0 +1,22 @@
+import { DEFAULT_MAX_TOKENS, DEFAULT_MIN_TOKENS } from "../../config/constants.js";
+
+/**
+ * Adjust max_tokens based on request context
+ * @param {object} body - Request body
+ * @returns {number} Adjusted max_tokens
+ */
+export function adjustMaxTokens(body) {
+  let maxTokens = body.max_tokens || DEFAULT_MAX_TOKENS;
+  
+  // Auto-increase for tool calling to prevent truncated arguments
+  // Tool calls with large content (like writing files) need more tokens
+  if (body.tools && Array.isArray(body.tools) && body.tools.length > 0) {
+    if (maxTokens < DEFAULT_MIN_TOKENS) {
+      console.log(`[AUTO-ADJUST] max_tokens: ${maxTokens} → ${DEFAULT_MIN_TOKENS} (tool calling detected)`);
+      maxTokens = DEFAULT_MIN_TOKENS;
+    }
+  }
+  
+  return maxTokens;
+}
+

open-sse/translator/helpers/openaiHelper.js

@@ -0,0 +1,80 @@
+// OpenAI helper functions for translator
+
+// Valid OpenAI content block types
+export const VALID_OPENAI_CONTENT_TYPES = ["text", "image_url", "image"];
+export const VALID_OPENAI_MESSAGE_TYPES = ["text", "image_url", "image", "tool_calls", "tool_result"];
+
+// Filter messages to OpenAI standard format
+// Remove: thinking, redacted_thinking, signature, and other non-OpenAI blocks
+export function filterToOpenAIFormat(body) {
+  if (!body.messages || !Array.isArray(body.messages)) return body;
+  
+  body.messages = body.messages.map(msg => {
+    // Keep tool messages as-is (OpenAI format)
+    if (msg.role === "tool") return msg;
+    
+    // Keep assistant messages with tool_calls as-is
+    if (msg.role === "assistant" && msg.tool_calls) return msg;
+    
+    // Handle string content
+    if (typeof msg.content === "string") return msg;
+    
+    // Handle array content
+    if (Array.isArray(msg.content)) {
+      const filteredContent = [];
+      
+      for (const block of msg.content) {
+        // Skip thinking blocks
+        if (block.type === "thinking" || block.type === "redacted_thinking") continue;
+        
+        // Only keep valid OpenAI content types
+        if (VALID_OPENAI_CONTENT_TYPES.includes(block.type)) {
+          // Remove signature field if exists
+          const { signature, cache_control, ...cleanBlock } = block;
+          filteredContent.push(cleanBlock);
+        } else if (block.type === "tool_use") {
+          // Convert tool_use to tool_calls format (handled separately)
+          continue;
+        } else if (block.type === "tool_result") {
+          // Keep tool_result but clean it
+          const { signature, cache_control, ...cleanBlock } = block;
+          filteredContent.push(cleanBlock);
+        }
+      }
+      
+      // If all content was filtered, add empty text
+      if (filteredContent.length === 0) {
+        filteredContent.push({ type: "text", text: "" });
+      }
+      
+      return { ...msg, content: filteredContent };
+    }
+    
+    return msg;
+  });
+  
+  // Filter out messages with only empty text (but NEVER filter tool messages)
+  body.messages = body.messages.filter(msg => {
+    // Always keep tool messages
+    if (msg.role === "tool") return true;
+    // Always keep assistant messages with tool_calls
+    if (msg.role === "assistant" && msg.tool_calls) return true;
+    
+    if (typeof msg.content === "string") return msg.content.trim() !== "";
+    if (Array.isArray(msg.content)) {
+      return msg.content.some(b => 
+        (b.type === "text" && b.text?.trim()) ||
+        b.type !== "text"
+      );
+    }
+    return true;
+  });
+
+  // Remove empty tools array (some providers like QWEN reject it)
+  if (body.tools && Array.isArray(body.tools) && body.tools.length === 0) {
+    delete body.tools;
+  }
+
+  return body;
+}
+

open-sse/translator/helpers/responsesApiHelper.js

@@ -0,0 +1,103 @@
+/**
+ * Convert OpenAI Responses API format to standard chat completions format
+ * Responses API uses: { input: [...], instructions: "..." }
+ * Chat API uses: { messages: [...] }
+ */
+export function convertResponsesApiFormat(body) {
+  if (!body.input) return body;
+
+  const result = { ...body };
+  result.messages = [];
+
+  // Convert instructions to system message
+  if (body.instructions) {
+    result.messages.push({ role: "system", content: body.instructions });
+  }
+
+  // Group items by conversation turn
+  let currentAssistantMsg = null;
+  let pendingToolCalls = [];
+  let pendingToolResults = [];
+
+  for (const item of body.input) {
+    if (item.type === "message") {
+      // Flush any pending assistant message with tool calls
+      if (currentAssistantMsg) {
+        result.messages.push(currentAssistantMsg);
+        currentAssistantMsg = null;
+      }
+      // Flush pending tool results
+      if (pendingToolResults.length > 0) {
+        for (const tr of pendingToolResults) {
+          result.messages.push(tr);
+        }
+        pendingToolResults = [];
+      }
+
+      // Convert content: input_text → text, output_text → text
+      const content = Array.isArray(item.content)
+        ? item.content.map(c => {
+            if (c.type === "input_text") return { type: "text", text: c.text };
+            if (c.type === "output_text") return { type: "text", text: c.text };
+            return c;
+          })
+        : item.content;
+      result.messages.push({ role: item.role, content });
+    } 
+    else if (item.type === "function_call") {
+      // Start or append to assistant message with tool_calls
+      if (!currentAssistantMsg) {
+        currentAssistantMsg = {
+          role: "assistant",
+          content: null,
+          tool_calls: []
+        };
+      }
+      currentAssistantMsg.tool_calls.push({
+        id: item.call_id,
+        type: "function",
+        function: {
+          name: item.name,
+          arguments: item.arguments
+        }
+      });
+    }
+    else if (item.type === "function_call_output") {
+      // Flush assistant message first if exists
+      if (currentAssistantMsg) {
+        result.messages.push(currentAssistantMsg);
+        currentAssistantMsg = null;
+      }
+      // Add tool result
+      pendingToolResults.push({
+        role: "tool",
+        tool_call_id: item.call_id,
+        content: typeof item.output === "string" ? item.output : JSON.stringify(item.output)
+      });
+    }
+    else if (item.type === "reasoning") {
+      // Skip reasoning items - they are for display only
+      continue;
+    }
+  }
+
+  // Flush remaining
+  if (currentAssistantMsg) {
+    result.messages.push(currentAssistantMsg);
+  }
+  if (pendingToolResults.length > 0) {
+    for (const tr of pendingToolResults) {
+      result.messages.push(tr);
+    }
+  }
+
+  // Cleanup Responses API specific fields
+  delete result.input;
+  delete result.instructions;
+  delete result.include;
+  delete result.prompt_cache_key;
+  delete result.store;
+  delete result.reasoning;
+
+  return result;
+}

open-sse/translator/helpers/toolCallHelper.js

@@ -0,0 +1,111 @@
+// Tool call helper functions for translator
+
+// Generate unique tool call ID
+export function generateToolCallId() {
+  return `call_${Date.now().toString(36)}_${Math.random().toString(36).slice(2, 9)}`;
+}
+
+// Ensure all tool_calls have id field and arguments is string (some providers require it)
+export function ensureToolCallIds(body) {
+  if (!body.messages || !Array.isArray(body.messages)) return body;
+  
+  for (const msg of body.messages) {
+    if (msg.role === "assistant" && msg.tool_calls && Array.isArray(msg.tool_calls)) {
+      for (const tc of msg.tool_calls) {
+        if (!tc.id) {
+          tc.id = generateToolCallId();
+        }
+        if (!tc.type) {
+          tc.type = "function";
+        }
+        // Ensure arguments is JSON string, not object
+        if (tc.function?.arguments && typeof tc.function.arguments !== "string") {
+          tc.function.arguments = JSON.stringify(tc.function.arguments);
+        }
+      }
+    }
+  }
+  
+  return body;
+}
+
+// Get tool_call ids from assistant message (OpenAI format: tool_calls, Claude format: tool_use in content)
+export function getToolCallIds(msg) {
+  if (msg.role !== "assistant") return [];
+  
+  const ids = [];
+  
+  // OpenAI format: tool_calls array
+  if (msg.tool_calls && Array.isArray(msg.tool_calls)) {
+    for (const tc of msg.tool_calls) {
+      if (tc.id) ids.push(tc.id);
+    }
+  }
+  
+  // Claude format: tool_use blocks in content
+  if (Array.isArray(msg.content)) {
+    for (const block of msg.content) {
+      if (block.type === "tool_use" && block.id) {
+        ids.push(block.id);
+      }
+    }
+  }
+  
+  return ids;
+}
+
+// Check if user message has tool_result for given ids (OpenAI format: role=tool, Claude format: tool_result in content)
+export function hasToolResults(msg, toolCallIds) {
+  if (!msg || !toolCallIds.length) return false;
+  
+  // OpenAI format: role = "tool" with tool_call_id
+  if (msg.role === "tool" && msg.tool_call_id) {
+    return toolCallIds.includes(msg.tool_call_id);
+  }
+  
+  // Claude format: tool_result blocks in user message content
+  if (msg.role === "user" && Array.isArray(msg.content)) {
+    for (const block of msg.content) {
+      if (block.type === "tool_result" && toolCallIds.includes(block.tool_use_id)) {
+        return true;
+      }
+    }
+  }
+  
+  return false;
+}
+
+// Fix missing tool responses - insert empty tool_result if assistant has tool_use but next message has no tool_result
+export function fixMissingToolResponses(body) {
+  if (!body.messages || !Array.isArray(body.messages)) return body;
+  
+  const newMessages = [];
+  
+  for (let i = 0; i < body.messages.length; i++) {
+    const msg = body.messages[i];
+    const nextMsg = body.messages[i + 1];
+    
+    newMessages.push(msg);
+    
+    // Check if this is assistant with tool_calls/tool_use
+    const toolCallIds = getToolCallIds(msg);
+    if (toolCallIds.length === 0) continue;
+    
+    // Check if next message has tool_result
+    if (nextMsg && !hasToolResults(nextMsg, toolCallIds)) {
+      // Insert tool responses for each tool_call
+      for (const id of toolCallIds) {
+        // OpenAI format: role = "tool"
+        newMessages.push({
+          role: "tool",
+          tool_call_id: id,
+          content: ""
+        });
+      }
+    }
+  }
+  
+  body.messages = newMessages;
+  return body;
+}
+

open-sse/translator/index.js

@@ -0,0 +1,167 @@
+import { FORMATS } from "./formats.js";
+import { ensureToolCallIds, fixMissingToolResponses } from "./helpers/toolCallHelper.js";
+import { prepareClaudeRequest } from "./helpers/claudeHelper.js";
+import { filterToOpenAIFormat } from "./helpers/openaiHelper.js";
+import { normalizeThinkingConfig } from "../services/provider.js";
+
+// Registry for translators
+const requestRegistry = new Map();
+const responseRegistry = new Map();
+
+// Register translator
+export function register(from, to, requestFn, responseFn) {
+  const key = `${from}:${to}`;
+  if (requestFn) {
+    requestRegistry.set(key, requestFn);
+  }
+  if (responseFn) {
+    responseRegistry.set(key, responseFn);
+  }
+}
+
+// Translate request: source -> openai -> target
+export function translateRequest(sourceFormat, targetFormat, model, body, stream = true, credentials = null, provider = null) {
+  let result = body;
+
+  // Normalize thinking config: remove if lastMessage is not user
+  normalizeThinkingConfig(result);
+
+  // Always ensure tool_calls have id (some providers require it)
+  ensureToolCallIds(result);
+  
+  // Fix missing tool responses (insert empty tool_result if needed)
+  fixMissingToolResponses(result);
+
+  // If same format, skip translation steps
+  if (sourceFormat !== targetFormat) {
+    // Step 1: source -> openai (if source is not openai)
+    if (sourceFormat !== FORMATS.OPENAI) {
+      const toOpenAI = requestRegistry.get(`${sourceFormat}:${FORMATS.OPENAI}`);
+      if (toOpenAI) {
+        result = toOpenAI(model, result, stream, credentials);
+      }
+    }
+
+    // Step 1.5: Filter to clean OpenAI format (only when target is OpenAI)
+    if (targetFormat === FORMATS.OPENAI) {
+      result = filterToOpenAIFormat(result);
+    }
+
+    // Step 2: openai -> target (if target is not openai)
+    if (targetFormat !== FORMATS.OPENAI) {
+      const fromOpenAI = requestRegistry.get(`${FORMATS.OPENAI}:${targetFormat}`);
+      if (fromOpenAI) {
+        result = fromOpenAI(model, result, stream, credentials);
+      }
+    }
+  }
+
+  // Final step: prepare request for Claude format endpoints
+  if (targetFormat === FORMATS.CLAUDE) {
+    result = prepareClaudeRequest(result, provider);
+  }
+
+  return result;
+}
+
+// Translate response chunk: target -> openai -> source
+export function translateResponse(targetFormat, sourceFormat, chunk, state) {
+  // If same format, return as-is
+  if (sourceFormat === targetFormat) {
+    return [chunk];
+  }
+
+  let results = [chunk];
+
+  // Step 1: target -> openai (if target is not openai)
+  if (targetFormat !== FORMATS.OPENAI) {
+    const toOpenAI = responseRegistry.get(`${targetFormat}:${FORMATS.OPENAI}`);
+    if (toOpenAI) {
+      results = [];
+      const converted = toOpenAI(chunk, state);
+      if (converted) {
+        results = Array.isArray(converted) ? converted : [converted];
+      }
+    }
+  }
+
+  // Step 2: openai -> source (if source is not openai)
+  if (sourceFormat !== FORMATS.OPENAI) {
+    const fromOpenAI = responseRegistry.get(`${FORMATS.OPENAI}:${sourceFormat}`);
+    if (fromOpenAI) {
+      const finalResults = [];
+      for (const r of results) {
+        const converted = fromOpenAI(r, state);
+        if (converted) {
+          finalResults.push(...(Array.isArray(converted) ? converted : [converted]));
+        }
+      }
+      results = finalResults;
+    }
+  }
+
+  return results;
+}
+
+// Check if translation needed
+export function needsTranslation(sourceFormat, targetFormat) {
+  return sourceFormat !== targetFormat;
+}
+
+// Initialize state for streaming response based on format
+export function initState(sourceFormat) {
+  // Base state for all formats
+  const base = {
+    messageId: null,
+    model: null,
+    textBlockStarted: false,
+    thinkingBlockStarted: false,
+    inThinkingBlock: false,
+    currentBlockIndex: null,
+    toolCalls: new Map(),
+    finishReason: null,
+    finishReasonSent: false,
+    usage: null,
+    contentBlockIndex: -1
+  };
+
+  // Add openai-responses specific fields
+  if (sourceFormat === FORMATS.OPENAI_RESPONSES) {
+    return {
+      ...base,
+      seq: 0,
+      responseId: `resp_${Date.now()}`,
+      created: Math.floor(Date.now() / 1000),
+      started: false,
+      msgTextBuf: {},
+      msgItemAdded: {},
+      msgContentAdded: {},
+      msgItemDone: {},
+      reasoningId: "",
+      reasoningIndex: -1,
+      reasoningBuf: "",
+      reasoningPartAdded: false,
+      reasoningDone: false,
+      inThinking: false,
+      funcArgsBuf: {},
+      funcNames: {},
+      funcCallIds: {},
+      funcArgsDone: {},
+      funcItemDone: {},
+      completedSent: false
+    };
+  }
+
+  return base;
+}
+
+// Initialize all translators
+export async function initTranslators() {
+  await import("./to-openai/claude.js");
+  await import("./to-openai/gemini.js");
+  await import("./to-openai/openai.js");
+  await import("./to-openai/openai-responses.js");
+  await import("./from-openai/claude.js");
+  await import("./from-openai/gemini.js");
+  await import("./from-openai/openai-responses.js");
+}

open-sse/translator/to-openai/claude.js

@@ -0,0 +1,239 @@
+import { register } from "../index.js";
+import { FORMATS } from "../formats.js";
+import { adjustMaxTokens } from "../helpers/maxTokensHelper.js";
+
+// Convert Claude request to OpenAI format
+function claudeToOpenAI(model, body, stream) {
+  const result = {
+    model: model,
+    messages: [],
+    stream: stream
+  };
+
+  // Max tokens
+  if (body.max_tokens) {
+    result.max_tokens = adjustMaxTokens(body);
+  }
+
+  // Temperature
+  if (body.temperature !== undefined) {
+    result.temperature = body.temperature;
+  }
+
+  // System message
+  if (body.system) {
+    const systemContent = Array.isArray(body.system)
+      ? body.system.map(s => s.text || "").join("\n")
+      : body.system;
+    
+    if (systemContent) {
+      result.messages.push({
+        role: "system",
+        content: systemContent
+      });
+    }
+  }
+
+  // Convert messages
+  if (body.messages && Array.isArray(body.messages)) {
+    for (let i = 0; i < body.messages.length; i++) {
+      const msg = body.messages[i];
+      const converted = convertClaudeMessage(msg);
+      if (converted) {
+        // Handle array of messages (multiple tool results)
+        if (Array.isArray(converted)) {
+          result.messages.push(...converted);
+        } else {
+          result.messages.push(converted);
+        }
+      }
+    }
+  }
+
+  // Fix missing tool responses - OpenAI requires every tool_call to have a response
+  fixMissingToolResponses(result.messages);
+
+  // Tools
+  if (body.tools && Array.isArray(body.tools)) {
+    result.tools = body.tools.map(tool => ({
+      type: "function",
+      function: {
+        name: tool.name,
+        description: tool.description,
+        parameters: tool.input_schema || { type: "object", properties: {} }
+      }
+    }));
+  }
+
+  // Tool choice
+  if (body.tool_choice) {
+    result.tool_choice = convertToolChoice(body.tool_choice);
+  }
+
+  return result;
+}
+
+// Fix missing tool responses - add empty responses for tool_calls without responses
+function fixMissingToolResponses(messages) {
+  for (let i = 0; i < messages.length; i++) {
+    const msg = messages[i];
+    if (msg.role === "assistant" && msg.tool_calls && msg.tool_calls.length > 0) {
+      const toolCallIds = msg.tool_calls.map(tc => tc.id);
+      
+      // Collect all tool response IDs that IMMEDIATELY follow this assistant message
+      // Stop at any non-tool message (user or assistant)
+      const respondedIds = new Set();
+      let insertPosition = i + 1;
+      for (let j = i + 1; j < messages.length; j++) {
+        const nextMsg = messages[j];
+        if (nextMsg.role === "tool" && nextMsg.tool_call_id) {
+          respondedIds.add(nextMsg.tool_call_id);
+          insertPosition = j + 1;
+        } else {
+          // Stop at any non-tool message (user or assistant)
+          break;
+        }
+      }
+      
+      // Find missing responses and insert them
+      const missingIds = toolCallIds.filter(id => !respondedIds.has(id));
+      
+      if (missingIds.length > 0) {
+        const missingResponses = missingIds.map(id => ({
+          role: "tool",
+          tool_call_id: id,
+          content: "[No response received]"
+        }));
+        // Insert missing responses at the correct position
+        messages.splice(insertPosition, 0, ...missingResponses);
+        // Adjust index to skip inserted messages
+        i = insertPosition + missingResponses.length - 1;
+      }
+    }
+  }
+}
+
+// Convert single Claude message - returns single message or array of messages
+function convertClaudeMessage(msg) {
+  const role = msg.role === "user" || msg.role === "tool" ? "user" : "assistant";
+  
+  // Simple string content
+  if (typeof msg.content === "string") {
+    return { role, content: msg.content };
+  }
+
+  // Array content
+  if (Array.isArray(msg.content)) {
+    const parts = [];
+    const toolCalls = [];
+    const toolResults = [];
+
+    for (const block of msg.content) {
+      switch (block.type) {
+        case "text":
+          parts.push({ type: "text", text: block.text });
+          break;
+
+        case "image":
+          if (block.source?.type === "base64") {
+            parts.push({
+              type: "image_url",
+              image_url: {
+                url: `data:${block.source.media_type};base64,${block.source.data}`
+              }
+            });
+          }
+          break;
+
+        case "tool_use":
+          toolCalls.push({
+            id: block.id,
+            type: "function",
+            function: {
+              name: block.name,
+              arguments: JSON.stringify(block.input || {})
+            }
+          });
+          break;
+
+        case "tool_result":
+          // Extract actual content from tool_result
+          let resultContent = "";
+          if (typeof block.content === "string") {
+            resultContent = block.content;
+          } else if (Array.isArray(block.content)) {
+            // Claude tool_result content can be array of text blocks
+            resultContent = block.content
+              .filter(c => c.type === "text")
+              .map(c => c.text)
+              .join("\n") || JSON.stringify(block.content);
+          } else if (block.content) {
+            resultContent = JSON.stringify(block.content);
+          }
+          
+          toolResults.push({
+            role: "tool",
+            tool_call_id: block.tool_use_id,
+            content: resultContent
+          });
+          break;
+      }
+    }
+
+    // If has tool results, return array of tool messages
+    if (toolResults.length > 0) {
+      // Also include text parts as user message if any
+      if (parts.length > 0) {
+        const textContent = parts.length === 1 && parts[0].type === "text" 
+          ? parts[0].text 
+          : parts;
+        return [...toolResults, { role: "user", content: textContent }];
+      }
+      return toolResults;
+    }
+
+    // If has tool calls, return assistant message with tool_calls
+    if (toolCalls.length > 0) {
+      const result = { role: "assistant" };
+      if (parts.length > 0) {
+        result.content = parts.length === 1 && parts[0].type === "text" 
+          ? parts[0].text 
+          : parts;
+      }
+      result.tool_calls = toolCalls;
+      return result;
+    }
+
+    // Return content
+    if (parts.length > 0) {
+      return {
+        role,
+        content: parts.length === 1 && parts[0].type === "text" ? parts[0].text : parts
+      };
+    }
+    
+    // Empty content array - return empty string content to keep message in conversation
+    if (msg.content.length === 0) {
+      return { role, content: "" };
+    }
+  }
+
+  return null;
+}
+
+// Convert tool choice
+function convertToolChoice(choice) {
+  if (!choice) return "auto";
+  if (typeof choice === "string") return choice;
+  
+  switch (choice.type) {
+    case "auto": return "auto";
+    case "any": return "required";
+    case "tool": return { type: "function", function: { name: choice.name } };
+    default: return "auto";
+  }
+}
+
+// Register
+register(FORMATS.CLAUDE, FORMATS.OPENAI, claudeToOpenAI, null);
+

open-sse/translator/to-openai/gemini.js

@@ -0,0 +1,154 @@
+import { register } from "../index.js";
+import { FORMATS } from "../formats.js";
+import { adjustMaxTokens } from "../helpers/maxTokensHelper.js";
+
+// Convert Gemini request to OpenAI format
+function geminiToOpenAI(model, body, stream) {
+  const result = {
+    model: model,
+    messages: [],
+    stream: stream
+  };
+
+  // Generation config
+  if (body.generationConfig) {
+    const config = body.generationConfig;
+    if (config.maxOutputTokens) {
+      // Create temporary body object for adjustMaxTokens
+      const tempBody = { max_tokens: config.maxOutputTokens, tools: body.tools };
+      result.max_tokens = adjustMaxTokens(tempBody);
+    }
+    if (config.temperature !== undefined) {
+      result.temperature = config.temperature;
+    }
+    if (config.topP !== undefined) {
+      result.top_p = config.topP;
+    }
+  }
+
+  // System instruction
+  if (body.systemInstruction) {
+    const systemText = extractGeminiText(body.systemInstruction);
+    if (systemText) {
+      result.messages.push({
+        role: "system",
+        content: systemText
+      });
+    }
+  }
+
+  // Convert contents to messages
+  if (body.contents && Array.isArray(body.contents)) {
+    for (const content of body.contents) {
+      const converted = convertGeminiContent(content);
+      if (converted) {
+        result.messages.push(converted);
+      }
+    }
+  }
+
+  // Tools
+  if (body.tools && Array.isArray(body.tools)) {
+    result.tools = [];
+    for (const tool of body.tools) {
+      if (tool.functionDeclarations) {
+        for (const func of tool.functionDeclarations) {
+          result.tools.push({
+            type: "function",
+            function: {
+              name: func.name,
+              description: func.description || "",
+              parameters: func.parameters || { type: "object", properties: {} }
+            }
+          });
+        }
+      }
+    }
+  }
+
+  return result;
+}
+
+// Convert Gemini content to OpenAI message
+function convertGeminiContent(content) {
+  const role = content.role === "user" ? "user" : "assistant";
+  
+  if (!content.parts || !Array.isArray(content.parts)) {
+    return null;
+  }
+
+  const parts = [];
+  const toolCalls = [];
+
+  for (const part of content.parts) {
+    // Text
+    if (part.text !== undefined) {
+      parts.push({ type: "text", text: part.text });
+    }
+
+    // Image
+    if (part.inlineData) {
+      parts.push({
+        type: "image_url",
+        image_url: {
+          url: `data:${part.inlineData.mimeType};base64,${part.inlineData.data}`
+        }
+      });
+    }
+
+    // Function call
+    if (part.functionCall) {
+      toolCalls.push({
+        id: `call_${Date.now()}_${Math.random().toString(36).slice(2, 8)}`,
+        type: "function",
+        function: {
+          name: part.functionCall.name,
+          arguments: JSON.stringify(part.functionCall.args || {})
+        }
+      });
+    }
+
+    // Function response - use id if available, fallback to name
+    if (part.functionResponse) {
+      return {
+        role: "tool",
+        tool_call_id: part.functionResponse.id || part.functionResponse.name,
+        content: JSON.stringify(part.functionResponse.response?.result || part.functionResponse.response || {})
+      };
+    }
+  }
+
+  // Has tool calls
+  if (toolCalls.length > 0) {
+    const result = { role: "assistant" };
+    if (parts.length > 0) {
+      result.content = parts.length === 1 ? parts[0].text : parts;
+    }
+    result.tool_calls = toolCalls;
+    return result;
+  }
+
+  // Regular message
+  if (parts.length > 0) {
+    return {
+      role,
+      content: parts.length === 1 && parts[0].type === "text" ? parts[0].text : parts
+    };
+  }
+
+  return null;
+}
+
+// Extract text from Gemini content
+function extractGeminiText(content) {
+  if (typeof content === "string") return content;
+  if (content.parts && Array.isArray(content.parts)) {
+    return content.parts.map(p => p.text || "").join("");
+  }
+  return "";
+}
+
+// Register
+register(FORMATS.GEMINI, FORMATS.OPENAI, geminiToOpenAI, null);
+register(FORMATS.GEMINI_CLI, FORMATS.OPENAI, geminiToOpenAI, null);
+

open-sse/translator/to-openai/openai-responses.js

@@ -0,0 +1,140 @@
+/**
+ * Translator: OpenAI Responses API → OpenAI Chat Completions
+ * 
+ * Responses API uses: { input: [...], instructions: "..." }
+ * Chat API uses: { messages: [...] }
+ */
+import { register } from "../index.js";
+import { FORMATS } from "../formats.js";
+
+/**
+ * Convert OpenAI Responses API request to OpenAI Chat Completions format
+ */
+function translateRequest(model, body, stream, credentials) {
+  if (!body.input) return body;
+
+  const result = { ...body };
+  result.messages = [];
+
+  // Convert instructions to system message
+  if (body.instructions) {
+    result.messages.push({ role: "system", content: body.instructions });
+  }
+
+  // Group items by conversation turn
+  let currentAssistantMsg = null;
+  let pendingToolResults = [];
+
+  for (const item of body.input) {
+    if (item.type === "message") {
+      // Flush any pending assistant message with tool calls
+      if (currentAssistantMsg) {
+        result.messages.push(currentAssistantMsg);
+        currentAssistantMsg = null;
+      }
+      // Flush pending tool results
+      if (pendingToolResults.length > 0) {
+        for (const tr of pendingToolResults) {
+          result.messages.push(tr);
+        }
+        pendingToolResults = [];
+      }
+
+      // Convert content: input_text → text, output_text → text
+      const content = Array.isArray(item.content)
+        ? item.content.map(c => {
+            if (c.type === "input_text") return { type: "text", text: c.text };
+            if (c.type === "output_text") return { type: "text", text: c.text };
+            return c;
+          })
+        : item.content;
+      result.messages.push({ role: item.role, content });
+    } 
+    else if (item.type === "function_call") {
+      // Start or append to assistant message with tool_calls
+      if (!currentAssistantMsg) {
+        currentAssistantMsg = {
+          role: "assistant",
+          content: null,
+          tool_calls: []
+        };
+      }
+      currentAssistantMsg.tool_calls.push({
+        id: item.call_id,
+        type: "function",
+        function: {
+          name: item.name,
+          arguments: item.arguments
+        }
+      });
+    }
+    else if (item.type === "function_call_output") {
+      // Flush assistant message first if exists
+      if (currentAssistantMsg) {
+        result.messages.push(currentAssistantMsg);
+        currentAssistantMsg = null;
+      }
+      // Flush any pending tool results first
+      if (pendingToolResults.length > 0) {
+        for (const tr of pendingToolResults) {
+          result.messages.push(tr);
+        }
+        pendingToolResults = [];
+      }
+      // Add tool result immediately (not pending)
+      result.messages.push({
+        role: "tool",
+        tool_call_id: item.call_id,
+        content: typeof item.output === "string" ? item.output : JSON.stringify(item.output)
+      });
+    }
+    else if (item.type === "reasoning") {
+      // Skip reasoning items - they are for display only
+      continue;
+    }
+  }
+
+  // Flush remaining
+  if (currentAssistantMsg) {
+    result.messages.push(currentAssistantMsg);
+  }
+  if (pendingToolResults.length > 0) {
+    for (const tr of pendingToolResults) {
+      result.messages.push(tr);
+    }
+  }
+
+  // Tools are already in OpenAI format, just keep them
+  // Responses API tools: { type: "function", name, description, parameters }
+  // OpenAI tools: { type: "function", function: { name, description, parameters } }
+  if (body.tools && Array.isArray(body.tools)) {
+    result.tools = body.tools.map(tool => {
+      // Already has function wrapper
+      if (tool.function) return tool;
+      // Responses API format: flatten to OpenAI format
+      return {
+        type: "function",
+        function: {
+          name: tool.name,
+          description: tool.description,
+          parameters: tool.parameters,
+          strict: tool.strict
+        }
+      };
+    });
+  }
+
+  // Cleanup Responses API specific fields
+  delete result.input;
+  delete result.instructions;
+  delete result.include;
+  delete result.prompt_cache_key;
+  delete result.store;
+  delete result.reasoning;
+
+  return result;
+}
+
+// Register translator
+register(FORMATS.OPENAI_RESPONSES, FORMATS.OPENAI, translateRequest, null);
+

open-sse/translator/to-openai/openai.js

@@ -0,0 +1,372 @@
+import { register } from "../index.js";
+import { FORMATS } from "../formats.js";
+import { CLAUDE_SYSTEM_PROMPT } from "../../config/constants.js";
+import { adjustMaxTokens } from "../helpers/maxTokensHelper.js";
+
+// Convert OpenAI request to Claude format
+function openaiToClaude(model, body, stream) {
+  const result = {
+    model: model,
+    max_tokens: adjustMaxTokens(body),
+    stream: stream
+  };
+
+  // Temperature
+  if (body.temperature !== undefined) {
+    result.temperature = body.temperature;
+  }
+
+  // Messages
+  result.messages = [];
+  const systemParts = [];
+
+  if (body.messages && Array.isArray(body.messages)) {
+    // Extract system messages
+    for (const msg of body.messages) {
+      if (msg.role === "system") {
+        systemParts.push(typeof msg.content === "string" ? msg.content : extractTextContent(msg.content));
+      }
+    }
+    
+    // Filter out system messages for separate processing
+    const nonSystemMessages = body.messages.filter(m => m.role !== "system");
+    
+    // Process messages with merging logic
+    // CRITICAL: tool_result must be in separate message immediately after tool_use
+    let currentRole = undefined;
+    let currentParts = [];
+
+    const flushCurrentMessage = () => {
+      if (currentRole && currentParts.length > 0) {
+        result.messages.push({ role: currentRole, content: currentParts });
+        currentParts = [];
+      }
+    };
+
+    for (const msg of nonSystemMessages) {
+      const newRole = (msg.role === "user" || msg.role === "tool") ? "user" : "assistant";
+      const blocks = getContentBlocksFromMessage(msg);
+      const hasToolUse = blocks.some(b => b.type === "tool_use");
+      const hasToolResult = blocks.some(b => b.type === "tool_result");
+
+      // Separate tool_result from other content
+      if (hasToolResult) {
+        const toolResultBlocks = blocks.filter(b => b.type === "tool_result");
+        const otherBlocks = blocks.filter(b => b.type !== "tool_result");
+
+        // Flush current message first
+        flushCurrentMessage();
+
+        // Add tool_result as separate user message
+        if (toolResultBlocks.length > 0) {
+          result.messages.push({ role: "user", content: toolResultBlocks });
+        }
+
+        // Add other blocks to current parts for next message
+        if (otherBlocks.length > 0) {
+          currentRole = newRole;
+          currentParts.push(...otherBlocks);
+        }
+        continue;
+      }
+
+      if (currentRole !== newRole) {
+        flushCurrentMessage();
+        currentRole = newRole;
+      }
+
+      currentParts.push(...blocks);
+
+      if (hasToolUse) {
+        flushCurrentMessage();
+      }
+    }
+
+    flushCurrentMessage();
+    
+    // Add cache_control to last assistant message (like worker.old)
+    for (let i = result.messages.length - 1; i >= 0; i--) {
+      const message = result.messages[i];
+      if (message.role === "assistant" && Array.isArray(message.content) && message.content.length > 0) {
+        const lastBlock = message.content[message.content.length - 1];
+        if (lastBlock) {
+          lastBlock.cache_control = { type: "ephemeral" };
+          break;
+        }
+      }
+    }
+  }
+
+  // System with Claude Code prompt and cache_control
+  const claudeCodePrompt = { type: "text", text: CLAUDE_SYSTEM_PROMPT };
+  
+  if (systemParts.length > 0) {
+    const systemText = systemParts.join("\n");
+    result.system = [
+      claudeCodePrompt,
+      { type: "text", text: systemText, cache_control: { type: "ephemeral", ttl: "1h" } }
+    ];
+  } else {
+    result.system = [claudeCodePrompt];
+  }
+
+  // Tools - convert from OpenAI format to Claude format
+  if (body.tools && Array.isArray(body.tools)) {
+    result.tools = body.tools.map(tool => {
+      // Handle both OpenAI format {type: "function", function: {...}} and direct format
+      const toolData = tool.type === "function" && tool.function ? tool.function : tool;
+      return {
+        name: toolData.name,
+        description: toolData.description || "",
+        input_schema: toolData.parameters || toolData.input_schema || { type: "object", properties: {}, required: [] }
+      };
+    });
+    
+    // Add cache control to last tool (like worker.old)
+    if (result.tools.length > 0) {
+      result.tools[result.tools.length - 1].cache_control = { type: "ephemeral", ttl: "1h" };
+    }
+    
+    // console.log("[CLAUDE TOOLS DEBUG] Converted tools:", result.tools.map(t => t.name));
+  }
+
+  // Tool choice
+  if (body.tool_choice) {
+    result.tool_choice = convertOpenAIToolChoice(body.tool_choice);
+  }
+
+  return result;
+}
+
+// Convert OpenAI request to Gemini format
+function openaiToGemini(model, body, stream) {
+  const result = {
+    contents: [],
+    generationConfig: {}
+  };
+
+  // Generation config
+  if (body.max_tokens) {
+    result.generationConfig.maxOutputTokens = body.max_tokens;
+  }
+  if (body.temperature !== undefined) {
+    result.generationConfig.temperature = body.temperature;
+  }
+  if (body.top_p !== undefined) {
+    result.generationConfig.topP = body.top_p;
+  }
+
+  // Messages
+  if (body.messages && Array.isArray(body.messages)) {
+    for (const msg of body.messages) {
+      if (msg.role === "system") {
+        result.systemInstruction = {
+          parts: [{ text: typeof msg.content === "string" ? msg.content : extractTextContent(msg.content) }]
+        };
+      } else if (msg.role === "tool") {
+        result.contents.push({
+          role: "function",
+          parts: [{
+            functionResponse: {
+              name: msg.tool_call_id,
+              response: tryParseJSON(msg.content)
+            }
+          }]
+        });
+      } else {
+        const converted = convertOpenAIToGeminiContent(msg);
+        if (converted) {
+          result.contents.push(converted);
+        }
+      }
+    }
+  }
+
+  // Tools
+  if (body.tools && Array.isArray(body.tools)) {
+    const validTools = body.tools.filter(tool => tool && tool.function && tool.function.name);
+    if (validTools.length > 0) {
+      result.tools = [{
+        functionDeclarations: validTools.map(tool => ({
+          name: tool.function.name,
+          description: tool.function.description || "",
+          parameters: tool.function.parameters || { type: "object", properties: {} }
+        }))
+      }];
+    }
+  }
+
+  return result;
+}
+
+// Get content blocks from single message (like src.cc getContentBlocksFromMessage)
+function getContentBlocksFromMessage(msg) {
+  const blocks = [];
+
+  if (msg.role === "tool") {
+    blocks.push({
+      type: "tool_result",
+      tool_use_id: msg.tool_call_id,
+      content: msg.content
+    });
+  } else if (msg.role === "user") {
+    if (typeof msg.content === "string") {
+      if (msg.content) {
+        blocks.push({ type: "text", text: msg.content });
+      }
+    } else if (Array.isArray(msg.content)) {
+      for (const part of msg.content) {
+        if (part.type === "text" && part.text) {
+          blocks.push({ type: "text", text: part.text });
+        } else if (part.type === "tool_result") {
+          blocks.push({
+            type: "tool_result",
+            tool_use_id: part.tool_use_id,
+            content: part.content,
+            ...(part.is_error && { is_error: part.is_error })
+          });
+        } else if (part.type === "image_url") {
+          const url = part.image_url.url;
+          const match = url.match(/^data:([^;]+);base64,(.+)$/);
+          if (match) {
+            blocks.push({
+              type: "image",
+              source: { type: "base64", media_type: match[1], data: match[2] }
+            });
+          }
+        } else if (part.type === "image" && part.source) {
+          blocks.push({ type: "image", source: part.source });
+        }
+      }
+    }
+  } else if (msg.role === "assistant") {
+    // Handle Anthropic format: content is array with tool_use blocks
+    if (Array.isArray(msg.content)) {
+      for (const part of msg.content) {
+        if (part.type === "text" && part.text) {
+          blocks.push({ type: "text", text: part.text });
+        } else if (part.type === "tool_use") {
+          blocks.push({ type: "tool_use", id: part.id, name: part.name, input: part.input });
+        }
+      }
+    } else if (msg.content) {
+      const text = typeof msg.content === "string" ? msg.content : extractTextContent(msg.content);
+      if (text) {
+        blocks.push({ type: "text", text });
+      }
+    }
+
+    // Handle OpenAI format: tool_calls array
+    if (msg.tool_calls && Array.isArray(msg.tool_calls)) {
+      for (const tc of msg.tool_calls) {
+        if (tc.type === "function") {
+          blocks.push({
+            type: "tool_use",
+            id: tc.id,
+            name: tc.function.name,
+            input: tryParseJSON(tc.function.arguments)
+          });
+        }
+      }
+    }
+  }
+
+  return blocks;
+}
+
+// Convert single OpenAI message to Claude format (for backward compatibility)
+function convertOpenAIMessage(msg) {
+  const role = msg.role === "assistant" ? "assistant" : "user";
+  const content = convertOpenAIMessageContent(msg);
+  
+  if (content.length === 0) return null;
+
+  return { role, content };
+}
+
+// Convert OpenAI message to Gemini content
+function convertOpenAIToGeminiContent(msg) {
+  const role = msg.role === "assistant" ? "model" : "user";
+  const parts = [];
+
+  // Text content
+  if (typeof msg.content === "string") {
+    if (msg.content) {
+      parts.push({ text: msg.content });
+    }
+  } else if (Array.isArray(msg.content)) {
+    for (const part of msg.content) {
+      if (part.type === "text") {
+        parts.push({ text: part.text });
+      } else if (part.type === "image_url") {
+        const url = part.image_url.url;
+        if (url.startsWith("data:")) {
+          const match = url.match(/^data:([^;]+);base64,(.+)$/);
+          if (match) {
+            parts.push({
+              inlineData: {
+                mimeType: match[1],
+                data: match[2]
+              }
+            });
+          }
+        }
+      }
+    }
+  }
+
+  // Tool calls
+  if (msg.tool_calls && Array.isArray(msg.tool_calls)) {
+    for (const tc of msg.tool_calls) {
+      parts.push({
+        functionCall: {
+          name: tc.function.name,
+          args: tryParseJSON(tc.function.arguments)
+        }
+      });
+    }
+  }
+
+  if (parts.length === 0) return null;
+
+  return { role, parts };
+}
+
+// Convert tool choice
+function convertOpenAIToolChoice(choice) {
+  if (!choice) return { type: "auto" };
+  // Passthrough if already Claude format
+  if (typeof choice === "object" && choice.type) return choice;
+  if (choice === "auto" || choice === "none") return { type: "auto" };
+  if (choice === "required") return { type: "any" };
+  if (typeof choice === "object" && choice.function) {
+    return { type: "tool", name: choice.function.name };
+  }
+  return { type: "auto" };
+}
+
+// Extract text from content
+function extractTextContent(content) {
+  if (typeof content === "string") return content;
+  if (Array.isArray(content)) {
+    return content.filter(c => c.type === "text").map(c => c.text).join("\n");
+  }
+  return "";
+}
+
+// Try parse JSON
+function tryParseJSON(str) {
+  if (typeof str !== "string") return str;
+  try {
+    return JSON.parse(str);
+  } catch {
+    return str;
+  }
+}
+
+// Register
+register(FORMATS.OPENAI, FORMATS.CLAUDE, openaiToClaude, null);
+register(FORMATS.OPENAI, FORMATS.GEMINI, openaiToGemini, null);
+register(FORMATS.OPENAI, FORMATS.GEMINI_CLI, openaiToGemini, null);
+
+

open-sse/utils/bypassHandler.js

@@ -0,0 +1,266 @@
+import { detectFormat } from "../services/provider.js";
+import { translateResponse, initState } from "../translator/index.js";
+import { FORMATS } from "../translator/formats.js";
+import { SKIP_PATTERNS } from "../config/constants.js";
+import { formatSSE } from "./stream.js";
+
+/**
+ * Check for bypass patterns (warmup, skip) - return fake response without calling provider
+ * Supports both streaming and non-streaming responses
+ * Returns response in the correct sourceFormat using translator
+ * 
+ * @param {object} body - Request body
+ * @param {string} model - Model name
+ * @returns {object|null} { success: true, response: Response } or null if not bypass
+ */
+export function handleBypassRequest(body, model) {
+  const messages = body.messages;
+  if (!messages?.length) return null;
+
+  // Helper to extract text from content
+  const getText = (content) => {
+    if (typeof content === "string") return content;
+    if (Array.isArray(content)) {
+      return content.filter(c => c.type === "text").map(c => c.text).join(" ");
+    }
+    return "";
+  };
+
+  let shouldBypass = false;
+
+  // Check warmup: first message "Warmup"
+  const firstText = getText(messages[0]?.content);
+  if (firstText === "Warmup") shouldBypass = true;
+
+  // Check count pattern: [{"role":"user","content":"count"}]
+  if (!shouldBypass && 
+      messages.length === 1 && 
+      messages[0]?.role === "user" && 
+      firstText === "count") {
+    shouldBypass = true;
+  }
+
+  // Check skip patterns
+  if (!shouldBypass && SKIP_PATTERNS?.length) {
+    const allText = messages.map(m => getText(m.content)).join(" ");
+    shouldBypass = SKIP_PATTERNS.some(p => allText.includes(p));
+  }
+
+  if (!shouldBypass) return null;
+
+  // Detect source format and stream mode
+  const sourceFormat = detectFormat(body);
+  const stream = body.stream !== false;
+
+  // Create bypass response using translator
+  if (stream) {
+    return createStreamingResponse(sourceFormat, model);
+  } else {
+    return createNonStreamingResponse(sourceFormat, model);
+  }
+}
+
+/**
+ * Create OpenAI standard format response
+ */
+function createOpenAIResponse(model) {
+  const id = `chatcmpl-${Date.now()}`;
+  const created = Math.floor(Date.now() / 1000);
+  const text = "CLI Command Execution: Clear Terminal";
+
+  return {
+    id,
+    object: "chat.completion",
+    created,
+    model,
+    choices: [{
+      index: 0,
+      message: {
+        role: "assistant",
+        content: text
+      },
+      finish_reason: "stop"
+    }],
+    usage: {
+      prompt_tokens: 1,
+      completion_tokens: 1,
+      total_tokens: 2
+    }
+  };
+}
+
+/**
+ * Create non-streaming response with translation
+ * Use translator to convert OpenAI → sourceFormat
+ */
+function createNonStreamingResponse(sourceFormat, model) {
+  const openaiResponse = createOpenAIResponse(model);
+  
+  // If sourceFormat is OpenAI, return directly
+  if (sourceFormat === FORMATS.OPENAI) {
+    return {
+      success: true,
+      response: new Response(JSON.stringify(openaiResponse), {
+        headers: {
+          "Content-Type": "application/json",
+          "Access-Control-Allow-Origin": "*"
+        }
+      })
+    };
+  }
+
+  // Use translator to convert: simulate streaming then collect all chunks
+  const state = initState(sourceFormat);
+  state.model = model;
+  
+  const openaiChunks = createOpenAIStreamingChunks(openaiResponse);
+  const allTranslated = [];
+  
+  for (const chunk of openaiChunks) {
+    const translated = translateResponse(FORMATS.OPENAI, sourceFormat, chunk, state);
+    if (translated?.length > 0) {
+      allTranslated.push(...translated);
+    }
+  }
+  
+  // Flush remaining
+  const flushed = translateResponse(FORMATS.OPENAI, sourceFormat, null, state);
+  if (flushed?.length > 0) {
+    allTranslated.push(...flushed);
+  }
+  
+  // For non-streaming, merge all chunks into final response
+  const finalResponse = mergeChunksToResponse(allTranslated, sourceFormat);
+  
+  return {
+    success: true,
+    response: new Response(JSON.stringify(finalResponse), {
+      headers: {
+        "Content-Type": "application/json",
+        "Access-Control-Allow-Origin": "*"
+      }
+    })
+  };
+}
+
+/**
+ * Create streaming response with translation
+ * Use translator to convert OpenAI chunks → sourceFormat
+ */
+function createStreamingResponse(sourceFormat, model) {
+  const openaiResponse = createOpenAIResponse(model);
+  const state = initState(sourceFormat);
+  state.model = model;
+
+  // Create OpenAI streaming chunks
+  const openaiChunks = createOpenAIStreamingChunks(openaiResponse);
+
+  // Translate each chunk to sourceFormat using translator
+  const translatedChunks = [];
+  
+  for (const chunk of openaiChunks) {
+    const translated = translateResponse(FORMATS.OPENAI, sourceFormat, chunk, state);
+    if (translated?.length > 0) {
+      for (const item of translated) {
+        translatedChunks.push(formatSSE(item, sourceFormat));
+      }
+    }
+  }
+
+  // Flush remaining events
+  const flushed = translateResponse(FORMATS.OPENAI, sourceFormat, null, state);
+  if (flushed?.length > 0) {
+    for (const item of flushed) {
+      translatedChunks.push(formatSSE(item, sourceFormat));
+    }
+  }
+
+  // Add [DONE]
+  translatedChunks.push("data: [DONE]\n\n");
+
+  return {
+    success: true,
+    response: new Response(translatedChunks.join(""), {
+      headers: {
+        "Content-Type": "text/event-stream",
+        "Cache-Control": "no-cache",
+        "Connection": "keep-alive",
+        "Access-Control-Allow-Origin": "*"
+      }
+    })
+  };
+}
+
+/**
+ * Merge translated chunks into final response object (for non-streaming)
+ * Takes the last complete chunk as the final response
+ */
+function mergeChunksToResponse(chunks, sourceFormat) {
+  if (!chunks || chunks.length === 0) {
+    return createOpenAIResponse("unknown");
+  }
+  
+  // For most formats, the last chunk before done contains the complete response
+  // Find the most complete chunk (usually the last one with content)
+  let finalChunk = chunks[chunks.length - 1];
+  
+  // For Claude format, find the message_stop or final message
+  if (sourceFormat === FORMATS.CLAUDE) {
+    const messageStop = chunks.find(c => c.type === "message_stop");
+    if (messageStop) {
+      // Reconstruct complete message from chunks
+      const contentDelta = chunks.find(c => c.type === "content_block_delta");
+      const messageDelta = chunks.find(c => c.type === "message_delta");
+      const messageStart = chunks.find(c => c.type === "message_start");
+      
+      if (messageStart?.message) {
+        finalChunk = messageStart.message;
+        // Merge usage if available
+        if (messageDelta?.usage) {
+          finalChunk.usage = messageDelta.usage;
+        }
+      }
+    }
+  }
+  
+  return finalChunk;
+}
+
+/**
+ * Create OpenAI streaming chunks from complete response
+ */
+function createOpenAIStreamingChunks(completeResponse) {
+  const { id, created, model, choices } = completeResponse;
+  const content = choices[0].message.content;
+
+  return [
+    // Chunk with content
+    {
+      id,
+      object: "chat.completion.chunk",
+      created,
+      model,
+      choices: [{
+        index: 0,
+        delta: {
+          role: "assistant",
+          content
+        },
+        finish_reason: null
+      }]
+    },
+    // Final chunk with finish_reason
+    {
+      id,
+      object: "chat.completion.chunk",
+      created,
+      model,
+      choices: [{
+        index: 0,
+        delta: {},
+        finish_reason: "stop"
+      }],
+      usage: completeResponse.usage
+    }
+  ];
+}

open-sse/utils/error.js

@@ -0,0 +1,133 @@
+// OpenAI-compatible error types mapping
+const ERROR_TYPES = {
+  400: { type: "invalid_request_error", code: "bad_request" },
+  401: { type: "authentication_error", code: "invalid_api_key" },
+  403: { type: "permission_error", code: "insufficient_quota" },
+  404: { type: "invalid_request_error", code: "model_not_found" },
+  429: { type: "rate_limit_error", code: "rate_limit_exceeded" },
+  500: { type: "server_error", code: "internal_server_error" },
+  502: { type: "server_error", code: "bad_gateway" },
+  503: { type: "server_error", code: "service_unavailable" },
+  504: { type: "server_error", code: "gateway_timeout" }
+};
+
+/**
+ * Build OpenAI-compatible error response body
+ * @param {number} statusCode - HTTP status code
+ * @param {string} message - Error message
+ * @returns {object} Error response object
+ */
+export function buildErrorBody(statusCode, message) {
+  const errorInfo = ERROR_TYPES[statusCode] || 
+    (statusCode >= 500 
+      ? { type: "server_error", code: "internal_server_error" }
+      : { type: "invalid_request_error", code: "" });
+
+  return {
+    error: {
+      message: message || getDefaultMessage(statusCode),
+      type: errorInfo.type,
+      code: errorInfo.code
+    }
+  };
+}
+
+/**
+ * Get default error message for status code
+ */
+function getDefaultMessage(statusCode) {
+  const messages = {
+    400: "Bad request",
+    401: "Invalid API key provided",
+    403: "You exceeded your current quota",
+    404: "Model not found",
+    429: "Rate limit exceeded",
+    500: "Internal server error",
+    502: "Bad gateway - upstream provider error",
+    503: "Service temporarily unavailable",
+    504: "Gateway timeout"
+  };
+  return messages[statusCode] || "An error occurred";
+}
+
+/**
+ * Create error Response object (for non-streaming)
+ * @param {number} statusCode - HTTP status code
+ * @param {string} message - Error message
+ * @returns {Response} HTTP Response object
+ */
+export function errorResponse(statusCode, message) {
+  return new Response(JSON.stringify(buildErrorBody(statusCode, message)), {
+    status: statusCode,
+    headers: {
+      "Content-Type": "application/json",
+      "Access-Control-Allow-Origin": "*"
+    }
+  });
+}
+
+/**
+ * Write error to SSE stream (for streaming)
+ * @param {WritableStreamDefaultWriter} writer - Stream writer
+ * @param {number} statusCode - HTTP status code
+ * @param {string} message - Error message
+ */
+export async function writeStreamError(writer, statusCode, message) {
+  const errorBody = buildErrorBody(statusCode, message);
+  const encoder = new TextEncoder();
+  await writer.write(encoder.encode(`data: ${JSON.stringify(errorBody)}\n\n`));
+}
+
+/**
+ * Parse upstream provider error response
+ * @param {Response} response - Fetch response from provider
+ * @returns {Promise<{statusCode: number, message: string}>}
+ */
+export async function parseUpstreamError(response) {
+  let message = "";
+  
+  try {
+    const text = await response.text();
+    
+    // Try parse as JSON
+    try {
+      const json = JSON.parse(text);
+      message = json.error?.message || json.message || json.error || text;
+    } catch {
+      message = text;
+    }
+  } catch {
+    message = `Upstream error: ${response.status}`;
+  }
+
+  return {
+    statusCode: response.status,
+    message: typeof message === "string" ? message : JSON.stringify(message)
+  };
+}
+
+/**
+ * Create error result for chatCore handler
+ * @param {number} statusCode - HTTP status code
+ * @param {string} message - Error message
+ * @returns {{ success: false, status: number, error: string, response: Response }}
+ */
+export function createErrorResult(statusCode, message) {
+  return {
+    success: false,
+    status: statusCode,
+    error: message,
+    response: errorResponse(statusCode, message)
+  };
+}
+
+/**
+ * Format provider error with context
+ * @param {Error} error - Original error
+ * @param {string} provider - Provider name
+ * @param {string} model - Model name
+ * @returns {string} Formatted error message
+ */
+export function formatProviderError(error, provider, model) {
+  return error.message || "Unknown error";
+}

open-sse/utils/ollamaTransform.js

@@ -0,0 +1,82 @@
+// Transform OpenAI SSE stream to Ollama JSON lines format
+export function transformToOllama(response, model) {
+  let buffer = "";
+  let pendingToolCalls = {};
+  
+  const transform = new TransformStream({
+    transform(chunk, controller) {
+      const text = new TextDecoder().decode(chunk);
+      buffer += text;
+      const lines = buffer.split("\n");
+      buffer = lines.pop() || "";
+
+      for (const line of lines) {
+        if (!line.startsWith("data:")) continue;
+        const data = line.slice(5).trim();
+        
+        if (data === "[DONE]") {
+          const ollamaEnd = JSON.stringify({ model, message: { role: "assistant", content: "" }, done: true }) + "\n";
+          controller.enqueue(new TextEncoder().encode(ollamaEnd));
+          return;
+        }
+
+        try {
+          const parsed = JSON.parse(data);
+          const delta = parsed.choices?.[0]?.delta || {};
+          const content = delta.content || "";
+          const toolCalls = delta.tool_calls;
+
+          if (toolCalls) {
+            for (const tc of toolCalls) {
+              const idx = tc.index;
+              if (!pendingToolCalls[idx]) {
+                pendingToolCalls[idx] = { id: tc.id, function: { name: "", arguments: "" } };
+              }
+              if (tc.function?.name) pendingToolCalls[idx].function.name += tc.function.name;
+              if (tc.function?.arguments) pendingToolCalls[idx].function.arguments += tc.function.arguments;
+            }
+          }
+
+          if (content) {
+            const ollama = JSON.stringify({ model, message: { role: "assistant", content }, done: false }) + "\n";
+            controller.enqueue(new TextEncoder().encode(ollama));
+          }
+
+          const finishReason = parsed.choices?.[0]?.finish_reason;
+          if (finishReason === "tool_calls" || finishReason === "stop") {
+            const toolCallsArr = Object.values(pendingToolCalls);
+            if (toolCallsArr.length > 0) {
+              const formattedCalls = toolCallsArr.map(tc => ({
+                function: {
+                  name: tc.function.name,
+                  arguments: JSON.parse(tc.function.arguments || "{}")
+                }
+              }));
+              const ollama = JSON.stringify({ 
+                model, 
+                message: { role: "assistant", content: "", tool_calls: formattedCalls }, 
+                done: true
+              }) + "\n";
+              controller.enqueue(new TextEncoder().encode(ollama));
+              pendingToolCalls = {};
+            } else if (finishReason === "stop") {
+              const ollamaEnd = JSON.stringify({ model, message: { role: "assistant", content: "" }, done: true }) + "\n";
+              controller.enqueue(new TextEncoder().encode(ollamaEnd));
+            }
+          }
+        } catch (e) {
+          // Silently ignore parse errors
+        }
+      }
+    },
+    flush(controller) {
+      const ollamaEnd = JSON.stringify({ model, message: { role: "assistant", content: "" }, done: true }) + "\n";
+      controller.enqueue(new TextEncoder().encode(ollamaEnd));
+    }
+  });
+
+  return new Response(response.body.pipeThrough(transform), {
+    headers: { "Content-Type": "application/x-ndjson", "Access-Control-Allow-Origin": "*" }
+  });
+}
+

open-sse/utils/requestLogger.js

@@ -0,0 +1,244 @@
+// Check if running in Node.js environment (has fs module)
+const isNode = typeof process !== "undefined" && process.versions?.node && typeof window === "undefined";
+
+// Check if logging is enabled via environment variable (default: false)
+const LOGGING_ENABLED = typeof process !== "undefined" && process.env?.ENABLE_REQUEST_LOGS === 'true';
+
+let fs = null;
+let path = null;
+let LOGS_DIR = null;
+
+// Lazy load Node.js modules (avoid top-level await)
+async function ensureNodeModules() {
+  if (!isNode || !LOGGING_ENABLED || fs) return;
+  try {
+    fs = await import("fs");
+    path = await import("path");
+    LOGS_DIR = path.join(typeof process !== "undefined" && process.cwd ? process.cwd() : ".", "logs");
+  } catch {
+    // Running in non-Node environment (Worker, Browser, etc.)
+  }
+}
+
+// Format timestamp for folder name: 20251228_143045
+function formatTimestamp(date = new Date()) {
+  const pad = (n) => String(n).padStart(2, "0");
+  const y = date.getFullYear();
+  const m = pad(date.getMonth() + 1);
+  const d = pad(date.getDate());
+  const h = pad(date.getHours());
+  const min = pad(date.getMinutes());
+  const s = pad(date.getSeconds());
+  return `${y}${m}${d}_${h}${min}${s}`;
+}
+
+// Create log session folder: {sourceFormat}_{targetFormat}_{model}_{timestamp}
+async function createLogSession(sourceFormat, targetFormat, model) {
+  await ensureNodeModules();
+  if (!fs || !LOGS_DIR) return null;
+  
+  try {
+    if (!fs.existsSync(LOGS_DIR)) {
+      fs.mkdirSync(LOGS_DIR, { recursive: true });
+    }
+    
+    const timestamp = formatTimestamp();
+    const safeModel = model.replace(/[/:]/g, "-");
+    const folderName = `${sourceFormat}_${targetFormat}_${safeModel}_${timestamp}`;
+    const sessionPath = path.join(LOGS_DIR, folderName);
+    
+    fs.mkdirSync(sessionPath, { recursive: true });
+    
+    return sessionPath;
+  } catch (err) {
+    console.log("[LOG] Failed to create log session:", err.message);
+    return null;
+  }
+}
+
+// Write JSON file
+function writeJsonFile(sessionPath, filename, data) {
+  if (!fs || !sessionPath) return;
+  
+  try {
+    const filePath = path.join(sessionPath, filename);
+    fs.writeFileSync(filePath, JSON.stringify(data, null, 2));
+  } catch (err) {
+    console.log(`[LOG] Failed to write ${filename}:`, err.message);
+  }
+}
+
+// Mask sensitive data in headers
+function maskSensitiveHeaders(headers) {
+  if (!headers) return {};
+  const masked = { ...headers };
+  const sensitiveKeys = ["authorization", "x-api-key", "cookie", "token"];
+  
+  for (const key of Object.keys(masked)) {
+    const lowerKey = key.toLowerCase();
+    if (sensitiveKeys.some(sk => lowerKey.includes(sk))) {
+      const value = masked[key];
+      if (value && value.length > 20) {
+        masked[key] = value.slice(0, 10) + "..." + value.slice(-5);
+      }
+    }
+  }
+  return masked;
+}
+
+// No-op logger when logging is disabled
+function createNoOpLogger() {
+  return {
+    sessionPath: null,
+    logClientRawRequest() {},
+    logRawRequest() {},
+    logFormatInfo() {},
+    logConvertedRequest() {},
+    logRawResponse() {},
+    logConvertedResponse() {},
+    logStreamChunk() {},
+    logStreamComplete() {},
+    logError() {}
+  };
+}
+
+/**
+ * Create a new log session and return logger functions
+ * @param {string} sourceFormat - Source format from client (claude, openai, etc.)
+ * @param {string} targetFormat - Target format to provider (antigravity, gemini-cli, etc.)
+ * @param {string} model - Model name
+ * @returns {Promise<object>} Promise that resolves to logger object with methods to log each stage
+ */
+export async function createRequestLogger(sourceFormat, targetFormat, model) {
+  // Return no-op logger if logging is disabled
+  if (!LOGGING_ENABLED) {
+    return createNoOpLogger();
+  }
+  
+  // Wait for session to be created before returning logger
+  const sessionPath = await createLogSession(sourceFormat, targetFormat, model);
+  
+  return {
+    get sessionPath() { return sessionPath; },
+    
+    // 0. Log client raw request (before any conversion)
+    logClientRawRequest(endpoint, body, headers = {}) {
+      writeJsonFile(sessionPath, "0_client_raw_request.json", {
+        timestamp: new Date().toISOString(),
+        endpoint,
+        headers: maskSensitiveHeaders(headers),
+        body
+      });
+    },
+    
+    // 1. Log raw request from client (after initial conversion like responsesApi)
+    logRawRequest(body, headers = {}) {
+      writeJsonFile(sessionPath, "1_raw_request.json", {
+        timestamp: new Date().toISOString(),
+        headers: maskSensitiveHeaders(headers),
+        body
+      });
+    },
+    
+    // 1a. Log format detection info
+    logFormatInfo(info) {
+      writeJsonFile(sessionPath, "1a_format_info.json", {
+        timestamp: new Date().toISOString(),
+        ...info
+      });
+    },
+    
+    // 2. Log converted request to send to provider
+    logConvertedRequest(url, headers, body) {
+      writeJsonFile(sessionPath, "2_converted_request.json", {
+        timestamp: new Date().toISOString(),
+        url,
+        headers: maskSensitiveHeaders(headers),
+        body
+      });
+    },
+    
+    // 3. Log provider response (for non-streaming or error)
+    logProviderResponse(status, statusText, headers, body) {
+      const filename = "3_provider_response.json";
+      writeJsonFile(sessionPath, filename, {
+        timestamp: new Date().toISOString(),
+        status,
+        statusText,
+        headers: headers ? (typeof headers.entries === "function" ? Object.fromEntries(headers.entries()) : headers) : {},
+        body
+      });
+    },
+    
+    // 3. Append streaming chunk to provider response
+    appendProviderChunk(chunk) {
+      if (!fs || !sessionPath) return;
+      try {
+        const filePath = path.join(sessionPath, "3_provider_response.txt");
+        fs.appendFileSync(filePath, chunk);
+      } catch (err) {
+        // Ignore append errors
+      }
+    },
+    
+    // 4. Log converted response to client (for non-streaming)
+    logConvertedResponse(body) {
+      writeJsonFile(sessionPath, "4_converted_response.json", {
+        timestamp: new Date().toISOString(),
+        body
+      });
+    },
+    
+    // 4. Append streaming chunk to converted response
+    appendConvertedChunk(chunk) {
+      if (!fs || !sessionPath) return;
+      try {
+        const filePath = path.join(sessionPath, "4_converted_response.txt");
+        fs.appendFileSync(filePath, chunk);
+      } catch (err) {
+        // Ignore append errors
+      }
+    },
+    
+    // 5. Log error
+    logError(error, requestBody = null) {
+      writeJsonFile(sessionPath, "5_error.json", {
+        timestamp: new Date().toISOString(),
+        error: error?.message || String(error),
+        stack: error?.stack,
+        requestBody
+      });
+    }
+  };
+}
+
+// Legacy functions for backward compatibility
+export function logRequest() {}
+export function logResponse() {}
+export function logError(provider, { error, url, model, requestBody }) {
+  if (!fs || !LOGS_DIR) return;
+  
+  try {
+    if (!fs.existsSync(LOGS_DIR)) {
+      fs.mkdirSync(LOGS_DIR, { recursive: true });
+    }
+    
+    const date = new Date().toISOString().split("T")[0];
+    const logPath = path.join(LOGS_DIR, `${provider}-${date}.log`);
+    
+    const logEntry = {
+      timestamp: new Date().toISOString(),
+      type: "error",
+      provider,
+      model,
+      url,
+      error: error?.message || String(error),
+      stack: error?.stack,
+      requestBody
+    };
+    
+    fs.appendFileSync(logPath, JSON.stringify(logEntry) + "\n");
+  } catch (err) {
+    console.log("[LOG] Failed to write error log:", err.message);
+  }
+}

open-sse/utils/stream.js

@@ -0,0 +1,278 @@
+import { translateResponse, initState } from "../translator/index.js";
+import { FORMATS } from "../translator/formats.js";
+
+// Get HH:MM timestamp
+function getTimeString() {
+  return new Date().toLocaleTimeString("en-US", { hour12: false, hour: "2-digit", minute: "2-digit" });
+}
+
+// Extract usage from any format (Claude, OpenAI, Gemini)
+function extractUsage(chunk) {
+  // Claude format (message_delta event)
+  if (chunk.type === "message_delta" && chunk.usage) {
+    return {
+      prompt_tokens: chunk.usage.input_tokens || 0,
+      completion_tokens: chunk.usage.output_tokens || 0,
+      cache_read_input_tokens: chunk.usage.cache_read_input_tokens,
+      cache_creation_input_tokens: chunk.usage.cache_creation_input_tokens
+    };
+  }
+  // OpenAI format
+  if (chunk.usage?.prompt_tokens !== undefined) {
+    return {
+      prompt_tokens: chunk.usage.prompt_tokens,
+      completion_tokens: chunk.usage.completion_tokens || 0,
+      cached_tokens: chunk.usage.prompt_tokens_details?.cached_tokens,
+      reasoning_tokens: chunk.usage.completion_tokens_details?.reasoning_tokens
+    };
+  }
+  // Gemini format
+  if (chunk.usageMetadata) {
+    return {
+      prompt_tokens: chunk.usageMetadata.promptTokenCount || 0,
+      completion_tokens: chunk.usageMetadata.candidatesTokenCount || 0,
+      reasoning_tokens: chunk.usageMetadata.thoughtsTokenCount
+    };
+  }
+  return null;
+}
+
+// ANSI color codes
+export const COLORS = {
+  reset: "\x1b[0m",
+  red: "\x1b[31m",
+  green: "\x1b[32m",
+  yellow: "\x1b[33m",
+  blue: "\x1b[34m",
+  cyan: "\x1b[36m"
+};
+
+// Log usage with cache info (green color)
+function logUsage(provider, usage) {
+  if (!usage) return;
+  
+  const p = provider?.toUpperCase() || "UNKNOWN";
+  const inTokens = usage.prompt_tokens || 0;
+  const outTokens = usage.completion_tokens || 0;
+  
+  let msg = `[${getTimeString()}] 📊 [USAGE] ${p} | in=${inTokens} | out=${outTokens}`;
+  
+  if (usage.cache_creation_input_tokens) msg += ` | cache_write=${usage.cache_creation_input_tokens}`;
+  if (usage.cache_read_input_tokens) msg += ` | cache_read=${usage.cache_read_input_tokens}`;
+  if (usage.cached_tokens) msg += ` | cached=${usage.cached_tokens}`;
+  if (usage.reasoning_tokens) msg += ` | reasoning=${usage.reasoning_tokens}`;
+  
+  console.log(`${COLORS.green}${msg}${COLORS.reset}`);
+}
+
+// Parse SSE data line
+function parseSSELine(line) {
+  if (!line || !line.startsWith("data:")) return null;
+  
+  const data = line.slice(5).trim();
+  if (data === "[DONE]") return { done: true };
+
+  try {
+    return JSON.parse(data);
+  } catch (error) {
+    // Log parse errors for debugging incomplete chunks
+    if (data.length > 0 && data.length < 1000) {
+      console.log(`[WARN] Failed to parse SSE line (${data.length} chars): ${data.substring(0, 100)}...`);
+    }
+    return null;
+  }
+}
+
+/**
+ * Format output as SSE
+ * @param {object} data - Data to format
+ * @param {string} sourceFormat - Target format for client
+ * @returns {string} SSE formatted string
+ */
+export function formatSSE(data, sourceFormat) {
+  if (data.done) return "data: [DONE]\n\n";
+  
+  // OpenAI Responses API format: has event field
+  if (data.event && data.data) {
+    return `event: ${data.event}\ndata: ${JSON.stringify(data.data)}\n\n`;
+  }
+  
+  // Claude format: include event prefix
+  if (sourceFormat === FORMATS.CLAUDE && data.type) {
+    return `event: ${data.type}\ndata: ${JSON.stringify(data)}\n\n`;
+  }
+  
+  return `data: ${JSON.stringify(data)}\n\n`;
+}
+
+/**
+ * Stream modes
+ */
+const STREAM_MODE = {
+  TRANSLATE: "translate",    // Full translation between formats
+  PASSTHROUGH: "passthrough" // No translation, normalize output, extract usage
+};
+
+/**
+ * Create unified SSE transform stream
+ * @param {object} options
+ * @param {string} options.mode - Stream mode: translate, passthrough
+ * @param {string} options.targetFormat - Provider format (for translate mode)
+ * @param {string} options.sourceFormat - Client format (for translate mode)
+ * @param {string} options.provider - Provider name
+ * @param {object} options.reqLogger - Request logger instance
+ */
+export function createSSEStream(options = {}) {
+  const { 
+    mode = STREAM_MODE.TRANSLATE, 
+    targetFormat, 
+    sourceFormat, 
+    provider = null, 
+    reqLogger = null 
+  } = options;
+
+  const decoder = new TextDecoder();
+  const encoder = new TextEncoder();
+  let buffer = "";
+  let usage = null;
+  
+  // State for translate mode
+  const state = mode === STREAM_MODE.TRANSLATE ? { ...initState(sourceFormat), provider } : null;
+
+  return new TransformStream({
+    transform(chunk, controller) {
+      const text = decoder.decode(chunk, { stream: true });
+      buffer += text;
+      reqLogger?.appendProviderChunk?.(text);
+
+      const lines = buffer.split("\n");
+      buffer = lines.pop() || "";
+
+      for (const line of lines) {
+        const trimmed = line.trim();
+        
+        // Passthrough mode: normalize and forward
+        if (mode === STREAM_MODE.PASSTHROUGH) {
+          if (trimmed.startsWith("data:") && trimmed.slice(5).trim() !== "[DONE]") {
+            try {
+              const parsed = JSON.parse(trimmed.slice(5).trim());
+              const extracted = extractUsage(parsed);
+              if (extracted) usage = extracted;
+            } catch {}
+          }
+          // Normalize: ensure "data: " has space
+          let output;
+          if (line.startsWith("data:") && !line.startsWith("data: ")) {
+            output = "data: " + line.slice(5) + "\n";
+          } else {
+            output = line + "\n";
+          }
+          reqLogger?.appendConvertedChunk?.(output);
+          controller.enqueue(encoder.encode(output));
+          continue;
+        }
+
+        // Translate mode
+        if (!trimmed) continue;
+
+        const parsed = parseSSELine(trimmed);
+        if (!parsed) continue;
+
+        if (parsed.done) {
+          const output = "data: [DONE]\n\n";
+          reqLogger?.appendConvertedChunk?.(output);
+          controller.enqueue(encoder.encode(output));
+          continue;
+        }
+
+        // Extract usage
+        const extracted = extractUsage(parsed);
+        if (extracted) state.usage = extracted;
+
+        // Translate and emit
+        const translated = translateResponse(targetFormat, sourceFormat, parsed, state);
+        if (translated?.length > 0) {
+          for (const item of translated) {
+            const output = formatSSE(item, sourceFormat);
+            reqLogger?.appendConvertedChunk?.(output);
+            controller.enqueue(encoder.encode(output));
+          }
+        }
+      }
+    },
+
+    flush(controller) {
+      try {
+        const remaining = decoder.decode();
+        if (remaining) buffer += remaining;
+
+        if (mode === STREAM_MODE.PASSTHROUGH) {
+          if (buffer) {
+            let output = buffer;
+            if (buffer.startsWith("data:") && !buffer.startsWith("data: ")) {
+              output = "data: " + buffer.slice(5);
+            }
+            reqLogger?.appendConvertedChunk?.(output);
+            controller.enqueue(encoder.encode(output));
+          }
+          if (usage) logUsage(provider, usage);
+          return;
+        }
+
+        // Translate mode: process remaining buffer
+        if (buffer.trim()) {
+          const parsed = parseSSELine(buffer.trim());
+          if (parsed && !parsed.done) {
+            const translated = translateResponse(targetFormat, sourceFormat, parsed, state);
+            if (translated?.length > 0) {
+              for (const item of translated) {
+                const output = formatSSE(item, sourceFormat);
+                reqLogger?.appendConvertedChunk?.(output);
+                controller.enqueue(encoder.encode(output));
+              }
+            }
+          }
+        }
+
+        // Flush remaining events (only once at stream end)
+        const flushed = translateResponse(targetFormat, sourceFormat, null, state);
+        if (flushed?.length > 0) {
+          for (const item of flushed) {
+            const output = formatSSE(item, sourceFormat);
+            reqLogger?.appendConvertedChunk?.(output);
+            controller.enqueue(encoder.encode(output));
+          }
+        }
+
+        // Send [DONE] and log usage
+        const doneOutput = "data: [DONE]\n\n";
+        reqLogger?.appendConvertedChunk?.(doneOutput);
+        controller.enqueue(encoder.encode(doneOutput));
+
+        if (state?.usage) logUsage(state.provider || targetFormat, state.usage);
+      } catch (error) {
+        console.log("Error in flush:", error);
+      }
+    }
+  });
+}
+
+// Convenience functions for backward compatibility
+export function createSSETransformStreamWithLogger(targetFormat, sourceFormat, provider = null, reqLogger = null) {
+  return createSSEStream({ 
+    mode: STREAM_MODE.TRANSLATE, 
+    targetFormat, 
+    sourceFormat, 
+    provider, 
+    reqLogger 
+  });
+}
+
+export function createPassthroughStreamWithLogger(provider = null, reqLogger = null) {
+  return createSSEStream({ 
+    mode: STREAM_MODE.PASSTHROUGH, 
+    provider, 
+    reqLogger 
+  });
+}
+

open-sse/utils/streamHandler.js

@@ -0,0 +1,131 @@
+// Stream handler with disconnect detection - shared for all providers
+
+// Get HH:MM timestamp
+function getTimeString() {
+  return new Date().toLocaleTimeString("en-US", { hour12: false, hour: "2-digit", minute: "2-digit" });
+}
+
+/**
+ * Create stream controller with abort and disconnect detection
+ * @param {object} options
+ * @param {function} options.onDisconnect - Callback when client disconnects
+ * @param {object} options.log - Logger instance
+ * @param {string} options.provider - Provider name
+ * @param {string} options.model - Model name
+ */
+export function createStreamController({ onDisconnect, log, provider, model } = {}) {
+  const abortController = new AbortController();
+  const startTime = Date.now();
+  let disconnected = false;
+  let abortTimeout = null;
+
+  const logStream = (status) => {
+    const duration = Date.now() - startTime;
+    const p = provider?.toUpperCase() || "UNKNOWN";
+    console.log(`[${getTimeString()}] 🌊 [STREAM] ${p} | ${model || "unknown"} | ${duration}ms | ${status}`);
+  };
+
+  return {
+    signal: abortController.signal,
+    startTime,
+
+    isConnected: () => !disconnected,
+
+    // Call when client disconnects
+    handleDisconnect: (reason = "client_closed") => {
+      if (disconnected) return;
+      disconnected = true;
+
+      logStream(`disconnect: ${reason}`);
+
+      // Delay abort to allow cleanup
+      abortTimeout = setTimeout(() => {
+        abortController.abort();
+      }, 500);
+
+      onDisconnect?.({ reason, duration: Date.now() - startTime });
+    },
+
+    // Call when stream completes normally
+    handleComplete: () => {
+      if (disconnected) return;
+      disconnected = true;
+
+      logStream("complete");
+
+      if (abortTimeout) {
+        clearTimeout(abortTimeout);
+        abortTimeout = null;
+      }
+    },
+
+    // Call on error
+    handleError: (error) => {
+      if (abortTimeout) {
+        clearTimeout(abortTimeout);
+        abortTimeout = null;
+      }
+
+      if (error.name === "AbortError") {
+        logStream("aborted");
+        return;
+      }
+
+      logStream(`error: ${error.message}`);
+    },
+
+    abort: () => abortController.abort()
+  };
+}
+
+/**
+ * Create transform stream with disconnect detection
+ * Wraps existing transform stream and adds abort capability
+ */
+export function createDisconnectAwareStream(transformStream, streamController) {
+  const reader = transformStream.readable.getReader();
+  const writer = transformStream.writable.getWriter();
+
+  return new ReadableStream({
+    async pull(controller) {
+      if (!streamController.isConnected()) {
+        controller.close();
+        return;
+      }
+
+      try {
+        const { done, value } = await reader.read();
+        if (done) {
+          streamController.handleComplete();
+          controller.close();
+          return;
+        }
+        controller.enqueue(value);
+      } catch (error) {
+        streamController.handleError(error);
+        controller.error(error);
+      }
+    },
+
+    cancel(reason) {
+      streamController.handleDisconnect(reason || "cancelled");
+      reader.cancel();
+      writer.abort();
+    }
+  });
+}
+
+/**
+ * Pipe provider response through transform with disconnect detection
+ * @param {Response} providerResponse - Response from provider
+ * @param {TransformStream} transformStream - Transform stream for SSE
+ * @param {object} streamController - Stream controller from createStreamController
+ */
+export function pipeWithDisconnect(providerResponse, transformStream, streamController) {
+  const transformedBody = providerResponse.body.pipeThrough(transformStream);
+  return createDisconnectAwareStream(
+    { readable: transformedBody, writable: { getWriter: () => ({ abort: () => {} }) } },
+    streamController
+  );
+}
+

package.json

@@ -18,7 +18,6 @@
     "next": "^15.2.0",
     "node-machine-id": "^1.1.12",
     "open": "^10.1.0",
-    "open-sse": "^1.0.0",
     "ora": "^5.4.1",
     "react": "19.2.1",
     "react-dom": "19.2.1",
@@ -26,9 +25,6 @@
     "uuid": "^13.0.0",
     "zustand": "^5.0.9"
   },
-  "overrides": {
-    "open-sse": "file:../open-sse"
-  },
   "devDependencies": {
     "@tailwindcss/postcss": "^4.1.18",
     "eslint": "^9",