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Getting started

Install

curl -LsSf https://raw.githubusercontent.com/romain-gilliotte/spectral/main/install.sh | bash

This installs uv if needed, then installs Spectral in an isolated environment with spectral available in ~/.local/bin/.

Load the Chrome extension

  1. Open chrome://extensions, enable Developer mode, click Load unpacked and select the extension/ directory from the repository
  2. Copy the extension ID shown on the card
  3. Connect the extension to the CLI:
spectral extension install --extension-id <paste-id-here>

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.

Analyze

Generate MCP tools from the captured traffic:

spectral mcp analyze myapp

If the app requires authentication, generate a login script and authenticate:

spectral auth analyze myapp
spectral auth login myapp

Use in Claude

Install the MCP server into Claude Desktop and/or Claude Code:

spectral mcp install

This auto-detects installed clients and registers the server. Use --target claude-desktop or --target claude-code to install to a specific client only. See MCP tools for details.

The server exposes all discovered API endpoints as tools. Authentication is handled automatically using stored tokens.

Next steps