Cursor IDE setup

Override OpenAI Base URL in Cursor to reach Claude 3.7 Sonnet, DeepSeek R1, and GPT-4o through CallAI.

1. Interaction modes & model picks

ScenarioShortcutModelWhy
Composer agentCmd + I / Ctrl + Iclaude-3-7-sonnetPrecise multi-file refactors
Inline Diff editCmd + K / Ctrl + Kclaude-3-7-sonnet / gpt-4oFast in-place patches
Sidebar Q&ACmd + L / Ctrl + Ldeepseek-chat / gpt-4o-miniLow-cost walkthroughs

2. Setup steps

Step 1: Open model settings

Press Cmd + , (Mac) or Ctrl + , (Windows), then open Models.

Step 2: Enable Override and fill fields

Check Override OpenAI Base URL and enter:

OpenAI Base URL: https://api.callaiapi.com/v1
API Key: sk-live-your-callai-key
Step 3: Add custom models

Under Model Names, add and enable:

claude-3-7-sonnetdeepseek-r1gpt-4odeepseek-chatclaude-3-5-sonnet
⚠️Troubleshooting 403 / 401

401 usually means the key is wrong or missing the sk-live- prefix. 403 often means a local proxy TUN mode is hijacking DNS — set api.callaiapi.com to Direct.

3. Production .cursorrules template

# Place at project root as .cursorrules
1. Language: Strict TypeScript — explicit types, no any.
2. Architecture: React function components + Hooks; Tailwind for UI; separate business logic from presentation.
3. Error handling: wrap network/async I/O in try/catch; no unhandled Promise rejections.
4. Tests: add Vitest/Jest cases under __tests__ for new core logic.
Seeing network or status-code errors?
Use the HTTP status checker to isolate auth vs network issues.
Diagnose HTTP status →