deepseek-cursor-proxy

Compatibility proxy connecting Cursor to DeepSeek thinking models (deepseek-v4-pro and deepseek-v4-flash).

What It Does

• ✅ Caches DeepSeek reasoning_content from regular and streamed responses, then restores it on later tool-call turns when Cursor omits it. See DeepSeek docs for more details.
• ✅ Mirrors streamed reasoning_content into Cursor-visible <think>...</think> text so that thinking tokens are shown in Cursor's UI. For BYOK/proxy mode, Cursor renders this as normal text, not as a native collapsible thinking block.
• ✅ Starts an ngrok tunnel so Cursor can reach the local proxy.
• ✅ Provides other compatibility fixes to make DeepSeek models run well in Cursor.

Why This Exists

This repository fixes the following Cursor + DeepSeek tool-call error with thinking mode enabled:

⚠️ Connection Error
Provider returned error:
{
  "error": {
    "message": "The reasoning_content in the thinking mode must be passed back to the API.",
    "type": "invalid_request_error",
    "param": null,
    "code": "invalid_request_error"
  }
}

Usage

Step 1: Set Up ngrok

Create an ngrok account, visit ngrok's Dashboard: https://dashboard.ngrok.com

Then, install and authenticate ngrok once:

brew install ngrok
ngrok config add-authtoken <your-ngrok-token>

Step 2: Add Cursor Custom Model

In Cursor, add the DeepSeek custom model and point it at this proxy:

• Model: deepseek-v4-pro
• API Key: your DeepSeek API key
• Base URL: your ngrok HTTPS URL with the /v1 API version path

For example, if ngrok dashboard shows https://example.ngrok-free.app, use:

https://example.ngrok-free.app/v1

Note: you can toggle the custom API on and off with:

• macOS: Cmd+Shift+0
• Windows/Linux: Ctrl+Shift+0

Step 3: Start the Proxy Server

Install and run the proxy:

conda create -n dcp python=3.10 -y
conda activate dcp
pip install -e .
deepseek-cursor-proxy --verbose

The proxy creates ~/.deepseek-cursor-proxy/config.yaml on first run.

This will also print the ngrok public URL. If it differs from the one in Cursor, update it in Cursor's Base URL field.

Step 4: Chat with DeepSeek in Cursor

Select deepseek-v4-pro in Cursor and use chat or agent mode as usual.

Debugging and Development

Run without ngrok for local curl testing:

PROXY_NGROK=false deepseek-cursor-proxy --port 9000 --verbose

Use another config file:

deepseek-cursor-proxy --config ./dev.config.yaml

Run tests:

PYTHONPATH=src python -m unittest discover -s tests