fix: pass model parameter to Claude and Codex SDKs

Previously, the model parameter was accepted by the /api/agent endpoint
and extracted from requests, but was never passed through to the Claude
SDK or Codex SDK, causing all requests to use default models regardless
of user selection.

Changes:
- Add model parameter to queryClaudeSDK() options in routes/agent.js
- Add model to threadOptions in openai-codex.js
- Remove unused /cost slash command and PRICING constants
- Centralize all model definitions in shared/modelConstants.js
- Update API documentation to dynamically load models from constants

server/claude-sdk.js

@@ -16,6 +16,7 @@ import { query } from '@anthropic-ai/claude-agent-sdk';
 import { promises as fs } from 'fs';
 import path from 'path';
 import os from 'os';
+import { CLAUDE_MODELS } from '../shared/modelConstants.js';
 
 // Session tracking: Map of session IDs to active query instances
 const activeSessions = new Map();
@@ -77,7 +78,7 @@ function mapCliOptionsToSDK(options = {}) {
 
   // Map model (default to sonnet)
   // Valid models: sonnet, opus, haiku, opusplan, sonnet[1m]
-  sdkOptions.model = options.model || 'sonnet';
+  sdkOptions.model = options.model || CLAUDE_MODELS.DEFAULT;
   console.log(`Using model: ${sdkOptions.model}`);
 
   // Map system prompt configuration

server/openai-codex.js

@@ -213,7 +213,8 @@ export async function queryCodex(command, options = {}, ws) {
       workingDirectory,
       skipGitRepoCheck: true,
       sandboxMode,
-      approvalPolicy
+      approvalPolicy,
+      model
     };
 
     // Start or resume thread

server/routes/agent.js

@@ -10,6 +10,7 @@ import { queryClaudeSDK } from '../claude-sdk.js';
 import { spawnCursor } from '../cursor-cli.js';
 import { queryCodex } from '../openai-codex.js';
 import { Octokit } from '@octokit/rest';
+import { CLAUDE_MODELS, CURSOR_MODELS, CODEX_MODELS } from '../../shared/modelConstants.js';
 
 const router = express.Router();
 
@@ -634,9 +635,14 @@ class ResponseCollector {
  *                          - true: Returns text/event-stream with incremental updates
  *                          - false: Returns complete JSON response after completion
  *
- * @param {string} model - (Optional) Model identifier for Cursor provider.
- *                        Only applicable when provider='cursor'.
- *                        Examples: 'gpt-4', 'claude-3-opus', etc.
+ * @param {string} model - (Optional) Model identifier for providers.
+ *
+ *                        Claude models: 'sonnet' (default), 'opus', 'haiku', 'opusplan', 'sonnet[1m]'
+ *                        Cursor models: 'gpt-5' (default), 'gpt-5.2', 'gpt-5.2-high', 'sonnet-4.5', 'opus-4.5',
+ *                                       'gemini-3-pro', 'composer-1', 'auto', 'gpt-5.1', 'gpt-5.1-high',
+ *                                       'gpt-5.1-codex', 'gpt-5.1-codex-high', 'gpt-5.1-codex-max',
+ *                                       'gpt-5.1-codex-max-high', 'opus-4.1', 'grok', and thinking variants
+ *                        Codex models: 'gpt-5.2' (default), 'gpt-5.1-codex-max', 'o3', 'o4-mini'
  *
  * @param {boolean} cleanup - (Optional) Auto-cleanup project directory after completion.
  *                           Default: true
@@ -939,6 +945,7 @@ router.post('/', validateExternalApiKey, async (req, res) => {
         projectPath: finalProjectPath,
         cwd: finalProjectPath,
         sessionId: null, // New session
+        model: model,
         permissionMode: 'bypassPermissions' // Bypass all permissions for API calls
       }, writer);
 
@@ -959,7 +966,7 @@ router.post('/', validateExternalApiKey, async (req, res) => {
         projectPath: finalProjectPath,
         cwd: finalProjectPath,
         sessionId: null,
-        model: model || 'gpt-5.2',
+        model: model || CODEX_MODELS.DEFAULT,
         permissionMode: 'bypassPermissions'
       }, writer);
     }

server/routes/commands.js

@@ -4,6 +4,7 @@ import path from 'path';
 import { fileURLToPath } from 'url';
 import os from 'os';
 import matter from 'gray-matter';
+import { CLAUDE_MODELS, CURSOR_MODELS, CODEX_MODELS } from '../../shared/modelConstants.js';
 
 const __filename = fileURLToPath(import.meta.url);
 const __dirname = path.dirname(__filename);
@@ -182,23 +183,15 @@ Custom commands can be created in:
   },
 
   '/model': async (args, context) => {
-    // Read available models from config or defaults
+    // Read available models from centralized constants
     const availableModels = {
-      claude: [
-        'claude-sonnet-4.5',
-        'claude-sonnet-4',
-        'claude-opus-4',
-        'claude-sonnet-3.5'
-      ],
-      cursor: [
-        'gpt-5',
-        'sonnet-4',
-        'opus-4.1'
-      ]
+      claude: CLAUDE_MODELS.OPTIONS.map(o => o.value),
+      cursor: CURSOR_MODELS.OPTIONS.map(o => o.value),
+      codex: CODEX_MODELS.OPTIONS.map(o => o.value)
     };
 
     const currentProvider = context?.provider || 'claude';
-    const currentModel = context?.model || 'claude-sonnet-4.5';
+    const currentModel = context?.model || CLAUDE_MODELS.DEFAULT;
 
     return {
       type: 'builtin',
@@ -216,50 +209,6 @@ Custom commands can be created in:
     };
   },
 
-  '/cost': async (args, context) => {
-    // Calculate token usage and cost
-    const sessionId = context?.sessionId;
-    const tokenUsage = context?.tokenUsage || { used: 0, total: 200000 };
-
-    const costPerMillion = {
-      'claude-sonnet-4.5': { input: 3, output: 15 },
-      'claude-sonnet-4': { input: 3, output: 15 },
-      'claude-opus-4': { input: 15, output: 75 },
-      'gpt-5': { input: 5, output: 15 }
-    };
-
-    const model = context?.model || 'claude-sonnet-4.5';
-    const rates = costPerMillion[model] || costPerMillion['claude-sonnet-4.5'];
-
-    // Estimate 70% input, 30% output
-    const estimatedInputTokens = Math.floor(tokenUsage.used * 0.7);
-    const estimatedOutputTokens = Math.floor(tokenUsage.used * 0.3);
-
-    const inputCost = (estimatedInputTokens / 1000000) * rates.input;
-    const outputCost = (estimatedOutputTokens / 1000000) * rates.output;
-    const totalCost = inputCost + outputCost;
-
-    return {
-      type: 'builtin',
-      action: 'cost',
-      data: {
-        tokenUsage: {
-          used: tokenUsage.used,
-          total: tokenUsage.total,
-          percentage: ((tokenUsage.used / tokenUsage.total) * 100).toFixed(1)
-        },
-        cost: {
-          input: inputCost.toFixed(4),
-          output: outputCost.toFixed(4),
-          total: totalCost.toFixed(4),
-          currency: 'USD'
-        },
-        model,
-        rates
-      }
-    };
-  },
-
   '/status': async (args, context) => {
     // Read version from package.json
     const packageJsonPath = path.join(path.dirname(__dirname), '..', 'package.json');

server/routes/cursor.js

@@ -6,6 +6,7 @@ import { spawn } from 'child_process';
 import sqlite3 from 'sqlite3';
 import { open } from 'sqlite';
 import crypto from 'crypto';
+import { CURSOR_MODELS } from '../../shared/modelConstants.js';
 
 const router = express.Router();
 
@@ -33,7 +34,7 @@ router.get('/config', async (req, res) => {
         config: {
           version: 1,
           model: {
-            modelId: "gpt-5",
+            modelId: CURSOR_MODELS.DEFAULT,
             displayName: "GPT-5"
           },
           permissions: {