Getting started

Requirements

• Node.js 20.19 or later in the Node 20 line, or Node.js 22.12 or later.
• A JavaScript or TypeScript project.
• A root tsconfig.json when TypeScript checks are enabled.

Install and initialize

npm install --save-dev signalint-mcp
npx signalint-mcp init

Run both commands from the project Signalint should check. The init command detects a root TypeScript config, Oxlint configuration, and Biome configuration, then writes a matching signalint.config.json. If it finds exactly one nearby MCP client, it offers to write the server entry; if detection is ambiguous, it asks which client to configure or prints exact snippets.

Connect a client

Claude Code

On native Windows, use the cmd /c wrapper:

claude mcp add --scope project signalint -- cmd /c npx --no-install signalint-mcp
claude mcp get signalint

On macOS or Linux, omit cmd /c.

Cursor

Create .cursor/mcp.json in the checked project:

{
  "mcpServers": {
    "signalint": {
      "command": "npx",
      "args": ["--no-install", "signalint-mcp"]
    }
  }
}

On native Windows, set command to cmd and set args to ["/c", "npx", "--no-install", "signalint-mcp"].

Antigravity

The init command can update Antigravity's MCP configuration, typically %USERPROFILE%\.gemini\antigravity\mcp_config.json on Windows. Use the same Windows cmd /c npx form and set cwd to the absolute project root.

Verify the connection

1. Restart or reconnect the MCP client after changing its configuration.
2. Call ping with an empty object. The result must be pong.
3. Call check_project with { "paths": ["."] }.

Check without an MCP client

npx --no-install signalint check .

The command exits with code 1 when issues are found, which is expected diagnostic behavior.