Capture Your Own APIs

Reverse-engineer any web, desktop, or mobile app into MCP tools.

1. Install the Chrome extension

Follow the installation steps if you haven’t already.

2. Capture traffic

1. Navigate to the web app you want to reverse-engineer
2. Click the Spectral extension icon → Start Capture
3. Browse the application — exercise the workflows you care about
4. Click Stop & Send — the capture is sent to the CLI via native messaging and stored automatically

You can repeat this for multiple sessions; captures are merged during analysis.

3. Analyze

Generate MCP tools from the captured traffic:

spectral mcp analyze myapp

4. Authenticate

If the app requires authentication, the fastest way is to extract tokens directly from your capture:

spectral auth extract myapp

This scans your captured traffic for auth headers and stores them. The tokens will expire eventually — see Authentication for renewable alternatives like generated login scripts.

5. Use

Your tools are ready. Authentication is handled automatically using stored tokens.

See Capture — Web for the full capture reference, or Desktop and Mobile for non-browser traffic.