/cursor/chat/completions - Cursor Endpoint

LiteLLM provides a Cursor-specific endpoint to make Cursor IDE work seamlessly with the LiteLLM Proxy when using BYOK + custom base_url.

• Accepts Requests in OpenAI Responses API input format (Cursor sends this)
• Returns Responses in OpenAI Chat Completions format (Cursor expects this)
• Supports streaming and non‑streaming

Endpoint

• Path: /cursor/chat/completions
• Auth: Standard LiteLLM Proxy auth (Authorization: Bearer <key>)
• Behavior: Internally routes to LiteLLM /responses flow and transforms output to Chat Completions

Why this exists

When setting up Cursor with BYOK against a custom base_url, Cursor sends requests to the Chat Completions endpoint but in the OpenAI Responses API input shape. Without translation, Cursor won’t display streamed output. This endpoint bridges the formats:

• Input: Responses API (input, tool calls, etc.)
• Output: Chat Completions (choices, delta, finish_reason, etc.)

Usage

Non-streaming

curl -X POST https://litellm-internal/cursor/chat/completions \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer sk-1234" \
  -d '{
    "model": "gpt-4o",
    "input": [{"role": "user", "content": "Hello"}]
  }'

Example response (shape):

{
  "id": "chatcmpl-123",
  "object": "chat.completion",
  "created": 1733333333,
  "model": "gpt-4o",
  "choices": [
    {
      "index": 0,
      "message": {
        "role": "assistant",
        "content": "Hello! How can I help you?"
      },
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "prompt_tokens": 10,
    "completion_tokens": 8,
    "total_tokens": 18
  }
}

Streaming

curl -N -X POST https://litellm-internal/cursor/chat/completions \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer sk-1234" \
  -d '{
    "model": "gpt-4o",
    "input": [{"role": "user", "content": "Hello"}],
    "stream": true
  }'

• Server-Sent Events (SSE)
• Emits chat.completion.chunk deltas (choices[].delta) and ends with data: [DONE]

Configuration

Base URL Setup

Important: When configuring Cursor IDE to use this endpoint, you must include /cursor in the base URL.

Cursor automatically appends /chat/completions to the base URL you provide. To ensure requests go to /cursor/chat/completions, configure your base URL in Cursor as:

Base URL: https://litellm-internal/cursor

This way, when Cursor appends /chat/completions, the full path becomes /cursor/chat/completions, which is the correct endpoint.

Example: If your LiteLLM Proxy is running at https://litellm-internal, set the base URL in Cursor to https://litellm-internal/cursor (not just https://litellm-internal).

General Setup

No special configuration is required beyond your normal LiteLLM Proxy setup. Ensure that:

• Your config.yaml includes the models you want to call via this endpoint
• Your Cursor project uses your LiteLLM Proxy base_url (with /cursor included) and a valid API key

Notes

• This endpoint is intended specifically for Cursor’s request/response expectations. Other clients should continue to use /v1/chat/completions or /v1/responses as appropriate.