Merge pull request #577 from kaitranntt/feat/576-cursor-battle-test-integration

feat(cursor): harden daemon integration and model discovery

src/cursor/cursor-auth.ts

@@ -21,12 +21,24 @@ import * as os from 'os';
 import type { CursorCredentials, CursorAuthStatus, AutoDetectResult } from './types';
 import { getCcsDir } from '../utils/config-manager';
 
+/**
+ * Resolve home directory from environment first for deterministic testability,
+ * then fall back to os.homedir() when env vars are unavailable.
+ */
+function resolveHomeDir(): string {
+  if (process.platform === 'win32') {
+    return process.env.USERPROFILE || process.env.HOME || os.homedir();
+  }
+
+  return process.env.HOME || os.homedir();
+}
+
 /**
  * Get platform-specific path to Cursor's state.vscdb
  */
 export function getTokenStoragePath(): string {
   const platform = process.platform;
-  const home = os.homedir();
+  const home = resolveHomeDir();
 
   if (platform === 'win32') {
     const appData = process.env.APPDATA || path.join(home, 'AppData', 'Roaming');

src/cursor/cursor-client-policy.ts

@@ -0,0 +1,129 @@
+/**
+ * Cursor Client Policy
+ *
+ * Single source of truth for Cursor request identity headers and checksum generation.
+ */
+
+import * as crypto from 'crypto';
+import type { CursorApiCredentials } from './cursor-protobuf-schema';
+
+export const CURSOR_CLIENT_VERSION = '2.3.41';
+export const CURSOR_USER_AGENT = 'connect-es/1.6.1';
+
+function getClientOs(): string {
+  if (process.platform === 'win32') return 'windows';
+  if (process.platform === 'darwin') return 'macos';
+  return 'linux';
+}
+
+function getClientArch(): string {
+  return process.arch === 'arm64' ? 'aarch64' : 'x64';
+}
+
+export function normalizeCursorAccessToken(accessToken: string): string {
+  const delimIdx = accessToken.indexOf('::');
+  return delimIdx !== -1 ? accessToken.slice(delimIdx + 2) : accessToken;
+}
+
+/**
+ * Generate checksum using Jyh cipher (time-based XOR with rolling key seed=165)
+ */
+export function generateCursorChecksum(machineId: string, nowMs: number = Date.now()): string {
+  if (!machineId) {
+    throw new Error('Machine ID is required for Cursor API');
+  }
+
+  // Convert milliseconds to coarse ~1000-second units required by Cursor's checksum routine.
+  const timestamp = Math.floor(nowMs / 1000000);
+  // JS bitwise shifts wrap modulo 32, so >>40 and >>32 give wrong results.
+  // Use Math.trunc division for upper bytes that exceed 32-bit range.
+  const byteArray = new Uint8Array([
+    Math.trunc(timestamp / 2 ** 40) & 0xff,
+    Math.trunc(timestamp / 2 ** 32) & 0xff,
+    (timestamp >>> 24) & 0xff,
+    (timestamp >>> 16) & 0xff,
+    (timestamp >>> 8) & 0xff,
+    timestamp & 0xff,
+  ]);
+
+  let t = 165;
+  for (let i = 0; i < byteArray.length; i++) {
+    byteArray[i] = ((byteArray[i] ^ t) + (i % 256)) & 0xff;
+    t = byteArray[i];
+  }
+
+  const alphabet = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_';
+  let encoded = '';
+
+  for (let i = 0; i < byteArray.length; i += 3) {
+    const a = byteArray[i];
+    const b = i + 1 < byteArray.length ? byteArray[i + 1] : 0;
+    const c = i + 2 < byteArray.length ? byteArray[i + 2] : 0;
+
+    encoded += alphabet[a >> 2];
+    encoded += alphabet[((a & 3) << 4) | (b >> 4)];
+
+    if (i + 1 < byteArray.length) {
+      encoded += alphabet[((b & 15) << 2) | (c >> 6)];
+    }
+    if (i + 2 < byteArray.length) {
+      encoded += alphabet[c & 63];
+    }
+  }
+
+  return `${encoded}${machineId}`;
+}
+
+function buildCursorBaseHeaders(credentials: CursorApiCredentials): Record<string, string> {
+  const cleanToken = normalizeCursorAccessToken(credentials.accessToken);
+
+  if (!cleanToken) {
+    throw new Error('Access token is empty after parsing');
+  }
+
+  if (!credentials.machineId) {
+    throw new Error('Machine ID is required for Cursor API');
+  }
+
+  const ghostMode = credentials.ghostMode !== false;
+  const tokenHash = crypto.createHash('sha256').update(cleanToken).digest('hex');
+
+  return {
+    authorization: `Bearer ${cleanToken}`,
+    'x-amzn-trace-id': `Root=${crypto.randomUUID()}`,
+    'x-client-key': tokenHash,
+    'x-cursor-checksum': generateCursorChecksum(credentials.machineId),
+    'x-cursor-client-version': CURSOR_CLIENT_VERSION,
+    'x-cursor-client-type': 'ide',
+    'x-cursor-client-os': getClientOs(),
+    'x-cursor-client-arch': getClientArch(),
+    'x-cursor-client-device-type': 'desktop',
+    'x-cursor-config-version': crypto.randomUUID(),
+    'x-cursor-timezone': Intl.DateTimeFormat().resolvedOptions().timeZone || 'UTC',
+    'x-ghost-mode': ghostMode ? 'true' : 'false',
+    'x-request-id': crypto.randomUUID(),
+    'x-session-id': tokenHash.substring(0, 36),
+  };
+}
+
+export function buildCursorConnectHeaders(
+  credentials: CursorApiCredentials
+): Record<string, string> {
+  return {
+    ...buildCursorBaseHeaders(credentials),
+    'connect-accept-encoding': 'gzip',
+    'connect-protocol-version': '1',
+    'content-type': 'application/connect+proto',
+    'user-agent': CURSOR_USER_AGENT,
+  };
+}
+
+export function buildCursorModelsHeaders(
+  credentials: CursorApiCredentials
+): Record<string, string> {
+  return {
+    ...buildCursorBaseHeaders(credentials),
+    accept: 'application/json',
+    'user-agent': CURSOR_USER_AGENT,
+  };
+}

src/cursor/cursor-daemon-entry.ts

@@ -8,7 +8,7 @@ import * as http from 'http';
 import { Readable } from 'stream';
 import { CursorExecutor } from './cursor-executor';
 import { checkAuthStatus } from './cursor-auth';
-import { DEFAULT_CURSOR_MODEL, DEFAULT_CURSOR_MODELS } from './cursor-models';
+import { DEFAULT_CURSOR_MODEL, getModelsForDaemon } from './cursor-models';
 import type { CursorTool } from './cursor-protobuf-schema';
 
 interface DaemonRuntimeOptions {
@@ -59,12 +59,26 @@ function readJsonBody(req: http.IncomingMessage): Promise<unknown> {
   return new Promise((resolve, reject) => {
     const chunks: Buffer[] = [];
     let total = 0;
+    let settled = false;
+
+    const resolveOnce = (payload: unknown) => {
+      if (settled) return;
+      settled = true;
+      resolve(payload);
+    };
+
+    const rejectOnce = (error: Error) => {
+      if (settled) return;
+      settled = true;
+      reject(error);
+    };
 
     req.on('data', (chunk: Buffer) => {
       total += chunk.length;
       if (total > MAX_BODY_SIZE) {
-        req.destroy();
-        reject(new Error('Request body too large (max 10MB)'));
+        // Stop processing body, but avoid force-closing socket so caller can return 413 cleanly.
+        req.pause();
+        rejectOnce(new Error('Request body too large (max 10MB)'));
         return;
       }
       chunks.push(chunk);
@@ -73,17 +87,19 @@ function readJsonBody(req: http.IncomingMessage): Promise<unknown> {
     req.on('end', () => {
       const raw = Buffer.concat(chunks).toString('utf8').trim();
       if (!raw) {
-        resolve({});
+        resolveOnce({});
         return;
       }
       try {
-        resolve(JSON.parse(raw));
+        resolveOnce(JSON.parse(raw));
       } catch {
-        reject(new Error('Invalid JSON in request body'));
+        rejectOnce(new Error('Invalid JSON in request body'));
       }
     });
 
-    req.on('error', reject);
+    req.on('error', (error) => {
+      rejectOnce(error instanceof Error ? error : new Error(String(error)));
+    });
   });
 }
 
@@ -184,7 +200,19 @@ export function startCursorDaemonServer(options: DaemonRuntimeOptions): http.Ser
       }
 
       if (method === 'GET' && requestUrl === '/v1/models') {
-        const data = DEFAULT_CURSOR_MODELS.map((model) => ({
+        const authStatus = checkAuthStatus();
+        const models = await getModelsForDaemon({
+          credentials:
+            authStatus.authenticated && !authStatus.expired && authStatus.credentials
+              ? {
+                  accessToken: authStatus.credentials.accessToken,
+                  machineId: authStatus.credentials.machineId,
+                  ghostMode: options.ghostMode,
+                }
+              : null,
+        });
+
+        const data = models.map((model) => ({
           id: model.id,
           object: 'model',
           created: 0,
@@ -229,11 +257,15 @@ export function startCursorDaemonServer(options: DaemonRuntimeOptions): http.Ser
       }
 
       const abortController = new AbortController();
-      req.on('close', () => {
-        if (!res.writableEnded) {
+      const abortOnDisconnect = () => {
+        if (!abortController.signal.aborted && !res.writableEnded) {
           abortController.abort();
         }
-      });
+      };
+
+      req.on('aborted', abortOnDisconnect);
+      req.on('close', abortOnDisconnect);
+      res.on('close', abortOnDisconnect);
 
       const result = await executor.execute({
         model,
@@ -257,7 +289,8 @@ export function startCursorDaemonServer(options: DaemonRuntimeOptions): http.Ser
       await pipeWebResponseToNode(result.response, res);
     } catch (error) {
       const message = error instanceof Error ? error.message : 'Unknown error';
-      writeJson(res, 400, {
+      const isPayloadTooLarge = message.includes('Request body too large');
+      writeJson(res, isPayloadTooLarge ? 413 : 400, {
         error: {
           type: 'invalid_request_error',
           message,

src/cursor/cursor-default-models.ts

@@ -0,0 +1,173 @@
+/**
+ * Cursor Default Model Catalog
+ */
+
+import type { CursorModel } from './types';
+
+/** Default model ID */
+export const DEFAULT_CURSOR_MODEL = 'gpt-5.3-codex';
+
+/**
+ * Default models available through Cursor IDE.
+ * Used as fallback when daemon is not reachable.
+ * Source: Cursor docs model catalog (Feb 2026)
+ */
+export const DEFAULT_CURSOR_MODELS: CursorModel[] = [
+  // Anthropic Models
+  {
+    id: 'claude-4.6-opus',
+    name: 'Claude 4.6 Opus',
+    provider: 'anthropic',
+  },
+  {
+    id: 'claude-4.6-opus-fast-mode',
+    name: 'Claude 4.6 Opus (Fast mode)',
+    provider: 'anthropic',
+  },
+  {
+    id: 'claude-4.5-sonnet',
+    name: 'Claude 4.5 Sonnet',
+    provider: 'anthropic',
+  },
+  {
+    id: 'claude-4.5-opus',
+    name: 'Claude 4.5 Opus',
+    provider: 'anthropic',
+  },
+  {
+    id: 'claude-4.5-haiku',
+    name: 'Claude 4.5 Haiku',
+    provider: 'anthropic',
+  },
+  {
+    id: 'claude-4-sonnet',
+    name: 'Claude 4 Sonnet',
+    provider: 'anthropic',
+  },
+  {
+    id: 'claude-4-sonnet-1m',
+    name: 'Claude 4 Sonnet 1M',
+    provider: 'anthropic',
+  },
+
+  // Cursor Models
+  {
+    id: 'composer-1.5',
+    name: 'Composer 1.5',
+    provider: 'cursor',
+  },
+  {
+    id: 'composer-1',
+    name: 'Composer 1',
+    provider: 'cursor',
+  },
+
+  // OpenAI Models
+  {
+    id: 'gpt-5.3-codex',
+    name: 'GPT-5.3 Codex',
+    provider: 'openai',
+    isDefault: true,
+  },
+  {
+    id: 'gpt-5.2-codex',
+    name: 'GPT-5.2 Codex',
+    provider: 'openai',
+  },
+  {
+    id: 'gpt-5.2',
+    name: 'GPT-5.2',
+    provider: 'openai',
+  },
+  {
+    id: 'gpt-5.1-codex',
+    name: 'GPT-5.1 Codex',
+    provider: 'openai',
+  },
+  {
+    id: 'gpt-5.1-codex-max',
+    name: 'GPT-5.1 Codex Max',
+    provider: 'openai',
+  },
+  {
+    id: 'gpt-5.1-codex-mini',
+    name: 'GPT-5.1 Codex Mini',
+    provider: 'openai',
+  },
+  {
+    id: 'gpt-5-codex',
+    name: 'GPT-5-Codex',
+    provider: 'openai',
+  },
+  {
+    id: 'gpt-5',
+    name: 'GPT-5',
+    provider: 'openai',
+  },
+  {
+    id: 'gpt-5-fast',
+    name: 'GPT-5 Fast',
+    provider: 'openai',
+  },
+  {
+    id: 'gpt-5-mini',
+    name: 'GPT-5 Mini',
+    provider: 'openai',
+  },
+
+  // Google Models
+  {
+    id: 'gemini-3-pro',
+    name: 'Gemini 3 Pro',
+    provider: 'google',
+  },
+  {
+    id: 'gemini-3-pro-image-preview',
+    name: 'Gemini 3 Pro Image Preview',
+    provider: 'google',
+  },
+  {
+    id: 'gemini-3-flash',
+    name: 'Gemini 3 Flash',
+    provider: 'google',
+  },
+  {
+    id: 'gemini-2.5-flash',
+    name: 'Gemini 2.5 Flash',
+    provider: 'google',
+  },
+
+  // xAI Models
+  {
+    id: 'grok-code',
+    name: 'Grok Code',
+    provider: 'xai',
+  },
+];
+
+/**
+ * Detect provider from model ID.
+ */
+export function detectProvider(modelId: string): string {
+  if (modelId.includes('claude')) return 'anthropic';
+  if (modelId.includes('gpt') || /^o[1-9]\d*(-|$)/.test(modelId)) return 'openai';
+  if (modelId.includes('gemini')) return 'google';
+  if (modelId.includes('cursor') || modelId.includes('composer')) return 'cursor';
+  if (modelId.includes('grok')) return 'xai';
+  return 'unknown';
+}
+
+/**
+ * Format model ID to human-readable name.
+ */
+export function formatModelName(modelId: string): string {
+  const model = DEFAULT_CURSOR_MODELS.find((m) => m.id === modelId);
+  if (model) {
+    return model.name;
+  }
+
+  return modelId
+    .split('-')
+    .map((word) => word.charAt(0).toUpperCase() + word.slice(1))
+    .join(' ');
+}

src/cursor/cursor-executor.ts

@@ -3,11 +3,11 @@
  * Handles HTTP/2 requests to Cursor API with protobuf encoding/decoding
  */
 
-import * as crypto from 'crypto';
 import type { IncomingHttpHeaders } from 'http';
 import { generateCursorBody, extractTextFromResponse } from './cursor-protobuf.js';
 import { buildCursorRequest } from './cursor-translator.js';
-import type { CursorTool, CursorCredentials } from './cursor-protobuf-schema.js';
+import type { CursorTool, CursorApiCredentials } from './cursor-protobuf-schema.js';
+import { buildCursorConnectHeaders, generateCursorChecksum } from './cursor-client-policy.js';
 
 import { StreamingFrameParser, decompressPayload } from './cursor-stream-parser.js';
 
@@ -30,7 +30,7 @@ interface ExecutorParams {
     reasoning_effort?: string;
   };
   stream: boolean;
-  credentials: CursorCredentials;
+  credentials: CursorApiCredentials;
   signal?: AbortSignal;
 }
 
@@ -92,8 +92,6 @@ function createErrorResponse(jsonError: {
 export class CursorExecutor {
   private readonly baseUrl = 'https://api2.cursor.sh';
   private readonly chatPath = '/aiserver.v1.AiService/StreamChat';
-  private readonly CURSOR_CLIENT_VERSION = '2.3.41';
-  private readonly CURSOR_USER_AGENT = 'connect-es/1.6.1';
 
   buildUrl(): string {
     return `${this.baseUrl}${this.chatPath}`;
@@ -103,94 +101,18 @@ export class CursorExecutor {
    * Generate checksum using Jyh cipher (time-based XOR with rolling key seed=165)
    */
   generateChecksum(machineId: string): string {
-    const timestamp = Math.floor(Date.now() / 1000000);
-    // JS bitwise shifts wrap modulo 32, so >>40 and >>32 give wrong results.
-    // Use Math.trunc division for upper bytes that exceed 32-bit range.
-    const byteArray = new Uint8Array([
-      Math.trunc(timestamp / 2 ** 40) & 0xff,
-      Math.trunc(timestamp / 2 ** 32) & 0xff,
-      (timestamp >>> 24) & 0xff,
-      (timestamp >>> 16) & 0xff,
-      (timestamp >>> 8) & 0xff,
-      timestamp & 0xff,
-    ]);
-
-    let t = 165;
-    for (let i = 0; i < byteArray.length; i++) {
-      byteArray[i] = ((byteArray[i] ^ t) + (i % 256)) & 0xff;
-      t = byteArray[i];
-    }
-
-    const alphabet = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_';
-    let encoded = '';
-
-    for (let i = 0; i < byteArray.length; i += 3) {
-      const a = byteArray[i];
-      const b = i + 1 < byteArray.length ? byteArray[i + 1] : 0;
-      const c = i + 2 < byteArray.length ? byteArray[i + 2] : 0;
-
-      encoded += alphabet[a >> 2];
-      encoded += alphabet[((a & 3) << 4) | (b >> 4)];
-
-      if (i + 1 < byteArray.length) {
-        encoded += alphabet[((b & 15) << 2) | (c >> 6)];
-      }
-      if (i + 2 < byteArray.length) {
-        encoded += alphabet[c & 63];
-      }
-    }
-
-    return `${encoded}${machineId}`;
+    return generateCursorChecksum(machineId);
   }
 
-  buildHeaders(credentials: CursorCredentials): Record<string, string> {
-    const accessToken = credentials.accessToken;
-    const machineId = credentials.machineId;
-    const ghostMode = credentials.ghostMode !== false;
-
-    if (!machineId) {
-      throw new Error('Machine ID is required for Cursor API');
-    }
-
-    const delimIdx = accessToken.indexOf('::');
-    const cleanToken = delimIdx !== -1 ? accessToken.slice(delimIdx + 2) : accessToken;
-
-    if (!cleanToken) {
-      throw new Error('Access token is empty after parsing');
-    }
-
-    return {
-      authorization: `Bearer ${cleanToken}`,
-      'connect-accept-encoding': 'gzip',
-      'connect-protocol-version': '1',
-      'content-type': 'application/connect+proto',
-      'user-agent': this.CURSOR_USER_AGENT,
-      'x-amzn-trace-id': `Root=${crypto.randomUUID()}`,
-      'x-client-key': crypto.createHash('sha256').update(cleanToken).digest('hex'),
-      'x-cursor-checksum': this.generateChecksum(machineId),
-      'x-cursor-client-version': this.CURSOR_CLIENT_VERSION,
-      'x-cursor-client-type': 'ide',
-      'x-cursor-client-os':
-        process.platform === 'win32'
-          ? 'windows'
-          : process.platform === 'darwin'
-            ? 'macos'
-            : 'linux',
-      'x-cursor-client-arch': process.arch === 'arm64' ? 'aarch64' : 'x64',
-      'x-cursor-client-device-type': 'desktop',
-      'x-cursor-config-version': crypto.randomUUID(),
-      'x-cursor-timezone': Intl.DateTimeFormat().resolvedOptions().timeZone || 'UTC',
-      'x-ghost-mode': ghostMode ? 'true' : 'false',
-      'x-request-id': crypto.randomUUID(),
-      'x-session-id': crypto.createHash('sha256').update(cleanToken).digest('hex').substring(0, 36),
-    };
+  buildHeaders(credentials: CursorApiCredentials): Record<string, string> {
+    return buildCursorConnectHeaders(credentials);
   }
 
   transformRequest(
     model: string,
     body: ExecutorParams['body'],
     stream: boolean,
-    credentials: CursorCredentials
+    credentials: CursorApiCredentials
   ): Uint8Array {
     const translatedBody = buildCursorRequest(model, body, stream, credentials);
     const messages = translatedBody.messages || [];
@@ -398,12 +320,24 @@ export class CursorExecutor {
     const created = Math.floor(Date.now() / 1000);
 
     return new Promise((resolve, reject) => {
+      let settled = false;
+      const resolveOnce = (response: Response) => {
+        if (settled) return;
+        settled = true;
+        resolve(response);
+      };
+      const rejectOnce = (error: Error) => {
+        if (settled) return;
+        settled = true;
+        reject(error);
+      };
+
       const urlObj = new URL(url);
       const client = http2.connect(`https://${urlObj.host}`);
 
       client.on('error', (err) => {
         client.close();
-        reject(err);
+        rejectOnce(err instanceof Error ? err : new Error(String(err)));
       });
 
       const req = client.request({
@@ -420,7 +354,8 @@ export class CursorExecutor {
       if (signal) {
         const onAbort = () => {
           streamClosed = true;
-          // Close the ReadableStream controller so consumers don't hang on reader.read()
+
+          // If stream already started, close readable to unblock consumers.
           if (streamController) {
             try {
               streamController.close();
@@ -428,9 +363,12 @@ export class CursorExecutor {
               /* already closed */
             }
           }
+
           req.close();
           client.close();
+          rejectOnce(new Error('Request aborted'));
         };
+
         signal.addEventListener('abort', onAbort, { once: true });
         const cleanup = () => signal.removeEventListener('abort', onAbort);
         req.on('end', cleanup);
@@ -446,12 +384,12 @@ export class CursorExecutor {
           req.on('end', () => {
             client.close();
             const errorText = Buffer.concat(errorChunks).toString();
-            resolve(
+            resolveOnce(
               new Response(
                 JSON.stringify({
                   error: {
                     message: `[${status}]: ${errorText}`,
-                    type: 'invalid_request_error',
+                    type: status === 429 ? 'rate_limit_error' : 'invalid_request_error',
                     code: '',
                   },
                 }),
@@ -589,6 +527,15 @@ export class CursorExecutor {
                   emitSSE(buildChunk(delta, null));
                   chunkCount++;
                 }
+
+                if (frame.type === 'thinking') {
+                  const delta =
+                    chunkCount === 0 && toolCallCount === 0
+                      ? { role: 'assistant', reasoning_content: frame.text }
+                      : { reasoning_content: frame.text };
+                  emitSSE(buildChunk(delta, null));
+                  chunkCount++;
+                }
               }
             });
 
@@ -630,7 +577,7 @@ export class CursorExecutor {
           },
         });
 
-        resolve(
+        resolveOnce(
           new Response(readable, {
             status: 200,
             headers: {
@@ -644,7 +591,7 @@ export class CursorExecutor {
 
       req.on('error', (err) => {
         client.close();
-        reject(err);
+        rejectOnce(err instanceof Error ? err : new Error(String(err)));
       });
 
       req.write(body);
@@ -659,6 +606,7 @@ export class CursorExecutor {
   private *parseProtobufFrames(buffer: Buffer): Generator<
     | { type: 'error'; response: Response }
     | { type: 'text'; text: string }
+    | { type: 'thinking'; text: string }
     | {
         type: 'toolCall';
         toolCall: {
@@ -732,6 +680,10 @@ export class CursorExecutor {
       if (result.text) {
         yield { type: 'text', text: result.text };
       }
+
+      if (result.thinking) {
+        yield { type: 'thinking', text: result.thinking };
+      }
     }
   }
 
@@ -740,6 +692,7 @@ export class CursorExecutor {
     const created = Math.floor(Date.now() / 1000);
 
     let totalContent = '';
+    let totalReasoning = '';
     const toolCalls: Array<{
       id: string;
       type: string;
@@ -793,6 +746,10 @@ export class CursorExecutor {
       if (frame.type === 'text') {
         totalContent += frame.text;
       }
+
+      if (frame.type === 'thinking') {
+        totalReasoning += frame.text;
+      }
     }
 
     // Finalize remaining tool calls
@@ -814,6 +771,7 @@ export class CursorExecutor {
     const message: {
       role: string;
       content: string | null;
+      reasoning_content?: string | null;
       tool_calls?: Array<{
         id: string;
         type: string;
@@ -828,6 +786,10 @@ export class CursorExecutor {
       message.tool_calls = toolCalls;
     }
 
+    if (totalReasoning) {
+      message.reasoning_content = totalReasoning;
+    }
+
     const completion = {
       id: responseId,
       object: 'chat.completion',
@@ -992,6 +954,27 @@ export class CursorExecutor {
           })}\n\n`
         );
       }
+
+      if (frame.type === 'thinking') {
+        chunks.push(
+          `data: ${JSON.stringify({
+            id: responseId,
+            object: 'chat.completion.chunk',
+            created,
+            model,
+            choices: [
+              {
+                index: 0,
+                delta:
+                  chunks.length === 0 && toolCalls.length === 0
+                    ? { role: 'assistant', reasoning_content: frame.text }
+                    : { reasoning_content: frame.text },
+                finish_reason: null,
+              },
+            ],
+          })}\n\n`
+        );
+      }
     }
 
     if (chunks.length === 0 && toolCalls.length === 0) {

src/cursor/cursor-models.ts

@@ -2,156 +2,176 @@
  * Cursor Model Catalog
  *
  * Manages available models from Cursor IDE.
- * Based on Cursor's supported models catalog.
  */
 
 import * as http from 'http';
 import type { CursorModel } from './types';
+import type { CursorApiCredentials } from './cursor-protobuf-schema';
 import { isDaemonRunning } from './cursor-daemon';
+import { buildCursorModelsHeaders } from './cursor-client-policy';
+import {
+  DEFAULT_CURSOR_MODEL,
+  DEFAULT_CURSOR_MODELS,
+  detectProvider,
+  formatModelName,
+} from './cursor-default-models';
 
 /** Default daemon port */
 export const DEFAULT_CURSOR_PORT = 20129;
 
-/** Default model ID */
-export const DEFAULT_CURSOR_MODEL = 'gpt-5.3-codex';
+export { DEFAULT_CURSOR_MODEL, DEFAULT_CURSOR_MODELS, detectProvider, formatModelName };
 
-/**
- * Default models available through Cursor IDE.
- * Used as fallback when daemon is not reachable.
- * Source: Cursor docs model catalog (Feb 2026)
- */
-export const DEFAULT_CURSOR_MODELS: CursorModel[] = [
-  // Anthropic Models
-  {
-    id: 'claude-4.6-opus',
-    name: 'Claude 4.6 Opus',
-    provider: 'anthropic',
-  },
-  {
-    id: 'claude-4.6-opus-fast-mode',
-    name: 'Claude 4.6 Opus (Fast mode)',
-    provider: 'anthropic',
-  },
-  {
-    id: 'claude-4.5-sonnet',
-    name: 'Claude 4.5 Sonnet',
-    provider: 'anthropic',
-  },
-  {
-    id: 'claude-4.5-opus',
-    name: 'Claude 4.5 Opus',
-    provider: 'anthropic',
-  },
-  {
-    id: 'claude-4.5-haiku',
-    name: 'Claude 4.5 Haiku',
-    provider: 'anthropic',
-  },
-  {
-    id: 'claude-4-sonnet',
-    name: 'Claude 4 Sonnet',
-    provider: 'anthropic',
-  },
-  {
-    id: 'claude-4-sonnet-1m',
-    name: 'Claude 4 Sonnet 1M',
-    provider: 'anthropic',
-  },
+const CURSOR_MODELS_API_ENDPOINT = 'https://api2.cursor.sh/v1/models';
+const CURSOR_MODELS_CACHE_TTL_MS = 5 * 60 * 1000;
 
-  // Cursor Models
-  {
-    id: 'composer-1.5',
-    name: 'Composer 1.5',
-    provider: 'cursor',
-  },
-  {
-    id: 'composer-1',
-    name: 'Composer 1',
-    provider: 'cursor',
-  },
+let liveModelsCache: {
+  models: CursorModel[];
+  expiresAtMs: number;
+} | null = null;
 
-  // OpenAI Models
-  {
-    id: 'gpt-5.3-codex',
-    name: 'GPT-5.3 Codex',
-    provider: 'openai',
-    isDefault: true,
-  },
-  {
-    id: 'gpt-5.2-codex',
-    name: 'GPT-5.2 Codex',
-    provider: 'openai',
-  },
-  {
-    id: 'gpt-5.2',
-    name: 'GPT-5.2',
-    provider: 'openai',
-  },
-  {
-    id: 'gpt-5.1-codex',
-    name: 'GPT-5.1 Codex',
-    provider: 'openai',
-  },
-  {
-    id: 'gpt-5.1-codex-max',
-    name: 'GPT-5.1 Codex Max',
-    provider: 'openai',
-  },
-  {
-    id: 'gpt-5.1-codex-mini',
-    name: 'GPT-5.1 Codex Mini',
-    provider: 'openai',
-  },
-  {
-    id: 'gpt-5-codex',
-    name: 'GPT-5-Codex',
-    provider: 'openai',
-  },
-  {
-    id: 'gpt-5',
-    name: 'GPT-5',
-    provider: 'openai',
-  },
-  {
-    id: 'gpt-5-fast',
-    name: 'GPT-5 Fast',
-    provider: 'openai',
-  },
-  {
-    id: 'gpt-5-mini',
-    name: 'GPT-5 Mini',
-    provider: 'openai',
-  },
+interface CursorModelsApiResponse {
+  data?: Array<{ id?: unknown; name?: unknown; provider?: unknown }>;
+  models?: Array<{ id?: unknown; name?: unknown; provider?: unknown }>;
+}
 
-  // Google Models
-  {
-    id: 'gemini-3-pro',
-    name: 'Gemini 3 Pro',
-    provider: 'google',
-  },
-  {
-    id: 'gemini-3-pro-image-preview',
-    name: 'Gemini 3 Pro Image Preview',
-    provider: 'google',
-  },
-  {
-    id: 'gemini-3-flash',
-    name: 'Gemini 3 Flash',
-    provider: 'google',
-  },
-  {
-    id: 'gemini-2.5-flash',
-    name: 'Gemini 2.5 Flash',
-    provider: 'google',
-  },
+function debugLog(message: string, error?: unknown): void {
+  if (!process.env.CCS_DEBUG) return;
+  if (error) {
+    console.error(`[cursor] ${message}`, error);
+    return;
+  }
+  console.error(`[cursor] ${message}`);
+}
 
-  // xAI Models
-  {
-    id: 'grok-code',
-    name: 'Grok Code',
-    provider: 'xai',
-  },
-];
+function normalizeModelRecords(
+  records: Array<{ id?: unknown; name?: unknown; provider?: unknown }>
+): CursorModel[] {
+  const models: CursorModel[] = [];
+  for (const record of records) {
+    if (!record || typeof record !== 'object') continue;
+    if (typeof record.id !== 'string' || !record.id) continue;
+    const modelId = record.id;
+    const modelName = typeof record.name === 'string' && record.name ? record.name : modelId;
+    const provider =
+      typeof record.provider === 'string' && record.provider
+        ? record.provider
+        : detectProvider(modelId);
+    models.push({
+      id: modelId,
+      name: modelName,
+      provider,
+      isDefault: modelId === DEFAULT_CURSOR_MODEL,
+    });
+  }
+  return models;
+}
+
+function parseApiModelsResponse(payload: unknown): CursorModel[] | null {
+  if (!payload || typeof payload !== 'object') return null;
+  const response = payload as CursorModelsApiResponse;
+  const records = Array.isArray(response.data)
+    ? response.data
+    : Array.isArray(response.models)
+      ? response.models
+      : null;
+
+  if (!records) return null;
+
+  const models = normalizeModelRecords(records);
+  return models.length > 0 ? models : null;
+}
+
+function getCachedLiveModels(nowMs: number = Date.now()): CursorModel[] | null {
+  if (!liveModelsCache) return null;
+  if (liveModelsCache.expiresAtMs <= nowMs) {
+    liveModelsCache = null;
+    return null;
+  }
+  return liveModelsCache.models;
+}
+
+function setCachedLiveModels(models: CursorModel[], nowMs: number = Date.now()): void {
+  liveModelsCache = {
+    models,
+    expiresAtMs: nowMs + CURSOR_MODELS_CACHE_TTL_MS,
+  };
+}
+
+export function clearCursorModelsCache(): void {
+  liveModelsCache = null;
+}
+
+export async function fetchModelsFromCursorApi(
+  credentials: CursorApiCredentials,
+  options: {
+    endpoint?: string;
+    timeoutMs?: number;
+  } = {}
+): Promise<CursorModel[] | null> {
+  if (!credentials.accessToken || !credentials.machineId) {
+    return null;
+  }
+
+  const endpoint = options.endpoint || CURSOR_MODELS_API_ENDPOINT;
+  const timeoutMs = options.timeoutMs ?? 5000;
+  const abortController = new AbortController();
+  const timeout = setTimeout(() => abortController.abort(), timeoutMs);
+
+  try {
+    const response = await fetch(endpoint, {
+      method: 'GET',
+      headers: buildCursorModelsHeaders(credentials),
+      signal: abortController.signal,
+    });
+
+    if (!response.ok) {
+      if (response.status === 401 || response.status === 403) {
+        clearCursorModelsCache();
+      }
+      debugLog(`Cursor models API returned ${response.status} (${endpoint})`);
+      return null;
+    }
+
+    const payload = (await response.json()) as unknown;
+    const parsed = parseApiModelsResponse(payload);
+    if (!parsed) {
+      debugLog(`Cursor models API payload shape invalid (${endpoint})`);
+    }
+    return parsed;
+  } catch (error) {
+    debugLog(`Cursor models API fetch failed (${endpoint})`, error);
+    return null;
+  } finally {
+    clearTimeout(timeout);
+  }
+}
+
+export async function getModelsForDaemon(
+  options: {
+    credentials?: CursorApiCredentials | null;
+    endpoint?: string;
+    timeoutMs?: number;
+  } = {}
+): Promise<CursorModel[]> {
+  const cached = getCachedLiveModels();
+  if (cached) {
+    return cached;
+  }
+
+  const credentials = options.credentials;
+  if (credentials?.accessToken && credentials.machineId) {
+    const liveModels = await fetchModelsFromCursorApi(credentials, {
+      endpoint: options.endpoint,
+      timeoutMs: options.timeoutMs,
+    });
+    if (liveModels && liveModels.length > 0) {
+      setCachedLiveModels(liveModels);
+      return liveModels;
+    }
+  }
+
+  return DEFAULT_CURSOR_MODELS;
+}
 
 /**
  * Fetch available models from running cursor daemon.
@@ -184,6 +204,7 @@ export async function fetchModelsFromDaemon(port: number): Promise<CursorModel[]
         res.on('data', (chunk) => {
           data += chunk;
           if (data.length > MAX_BODY_SIZE) {
+            debugLog('Cursor daemon /v1/models body exceeded 1MB; falling back to defaults');
             req.destroy();
             safeResolve(DEFAULT_CURSOR_MODELS);
           }
@@ -191,30 +212,39 @@ export async function fetchModelsFromDaemon(port: number): Promise<CursorModel[]
 
         res.on('end', () => {
           try {
-            const response = JSON.parse(data) as { data?: Array<{ id: string }> };
-            if (response.data && Array.isArray(response.data)) {
-              const models: CursorModel[] = response.data.map((m) => ({
-                id: m.id,
-                name: formatModelName(m.id),
-                provider: detectProvider(m.id),
-                isDefault: m.id === DEFAULT_CURSOR_MODEL,
-              }));
+            const response = JSON.parse(data) as { data?: Array<{ id?: unknown }> };
+            if (Array.isArray(response.data)) {
+              const models: CursorModel[] = response.data
+                .filter((m) => m && typeof m.id === 'string' && m.id.length > 0)
+                .map((m) => ({
+                  id: m.id as string,
+                  name: formatModelName(m.id as string),
+                  provider: detectProvider(m.id as string),
+                  isDefault: m.id === DEFAULT_CURSOR_MODEL,
+                }));
               safeResolve(models.length > 0 ? models : DEFAULT_CURSOR_MODELS);
             } else {
+              debugLog('Cursor daemon /v1/models payload missing data[]; falling back to defaults');
               safeResolve(DEFAULT_CURSOR_MODELS);
             }
-          } catch {
+          } catch (error) {
+            debugLog(
+              'Cursor daemon /v1/models returned invalid JSON; falling back to defaults',
+              error
+            );
             safeResolve(DEFAULT_CURSOR_MODELS);
           }
         });
       }
     );
 
-    req.on('error', () => {
+    req.on('error', (error) => {
+      debugLog('Cursor daemon /v1/models request failed; falling back to defaults', error);
       safeResolve(DEFAULT_CURSOR_MODELS);
     });
 
     req.on('timeout', () => {
+      debugLog('Cursor daemon /v1/models request timed out; falling back to defaults');
       req.destroy();
       safeResolve(DEFAULT_CURSOR_MODELS);
     });
@@ -241,32 +271,3 @@ export async function getAvailableModels(port: number): Promise<CursorModel[]> {
 export function getDefaultModel(): string {
   return DEFAULT_CURSOR_MODEL;
 }
-
-/**
- * Detect provider from model ID.
- */
-export function detectProvider(modelId: string): string {
-  if (modelId.includes('claude')) return 'anthropic';
-  if (modelId.includes('gpt') || /^o[1-9]\d*(-|$)/.test(modelId)) return 'openai';
-  if (modelId.includes('gemini')) return 'google';
-  if (modelId.includes('cursor') || modelId.includes('composer')) return 'cursor';
-  if (modelId.includes('grok')) return 'xai';
-  return 'unknown';
-}
-
-/**
- * Format model ID to human-readable name.
- */
-export function formatModelName(modelId: string): string {
-  // Find model in catalog for metadata
-  const model = DEFAULT_CURSOR_MODELS.find((m) => m.id === modelId);
-  if (model) {
-    return model.name;
-  }
-
-  // Fallback: convert kebab-case to title case
-  return modelId
-    .split('-')
-    .map((word) => word.charAt(0).toUpperCase() + word.slice(1))
-    .join(' ');
-}

src/cursor/cursor-protobuf-decoder.ts

@@ -326,11 +326,15 @@ export function extractTextFromResponse(payload: Uint8Array): {
       }
     }
 
+    if (payload.length > 0) {
+      return { text: null, error: 'Malformed protobuf response', toolCall: null, thinking: null };
+    }
+
     return { text: null, error: null, toolCall: null, thinking: null };
   } catch (err) {
     if (process.env.CCS_DEBUG) {
       console.error('[cursor] extractTextFromResponse parsing failed:', err);
     }
-    return { text: null, error: null, toolCall: null, thinking: null };
+    return { text: null, error: 'Malformed protobuf response', toolCall: null, thinking: null };
   }
 }

src/cursor/cursor-protobuf-schema.ts

@@ -135,7 +135,7 @@ export type UnifiedModeType = (typeof UNIFIED_MODE)[keyof typeof UNIFIED_MODE];
 export type ThinkingLevelType = (typeof THINKING_LEVEL)[keyof typeof THINKING_LEVEL];
 
 /** Cursor credentials structure */
-export interface CursorCredentials {
+export interface CursorApiCredentials {
   accessToken: string;
   machineId: string;
   ghostMode?: boolean;

src/cursor/index.ts

@@ -34,8 +34,11 @@ export {
   DEFAULT_CURSOR_PORT,
   DEFAULT_CURSOR_MODEL,
   fetchModelsFromDaemon,
+  fetchModelsFromCursorApi,
+  getModelsForDaemon,
   getAvailableModels,
   getDefaultModel,
+  clearCursorModelsCache,
   detectProvider,
   formatModelName,
 } from './cursor-models';