calllint-mcp

The MCP server for CallLint — a static preflight safety gate for MCP servers and agent tools.

Use CallLint before installing or approving other MCP servers. It produces evidence-backed verdicts — SAFE / REVIEW / BLOCK / UNKNOWN — for MCP configs and install snippets, entirely statically. It never executes the server it judges.

calllint-mcp is a thin wrapper: every tool delegates to the same engine behind the calllint CLI. No analysis logic of its own, no network on the scan path, no server execution.

The wrapper is versioned independently of the engine it embeds. The calllint-mcp version tracks the MCP surface (tools, transport, registry metadata); the bundled calllint engine — which decides the verdicts — is versioned separately and tracks verdict semantics. Each published wrapper bundles a specific engine build; run scan/explain and read the report's calllint version field for the exact engine in your installed copy.

Install

No install needed — run via npx:

// e.g. Claude Desktop / Cursor MCP config
{
  "mcpServers": {
    "calllint": {
      "command": "npx",
      "args": ["-y", "calllint-mcp"]
    }
  }
}

Tools

Tool	What it does
scan_mcp_config_path	Scan an MCP config file on disk → full ScanReport (verdict + evidence).
scan_mcp_config_json	Scan MCP config JSON → compact decisions (verdict, fingerprint, reason codes).
verify_baseline	Compare a config against a recorded baseline → drift / rug-pull signal.
explain_finding	Full evidence-backed explanation of why a verdict was reached.
generate_agent_rule	Emit the CallLint agent-safety rule for a host (claude, cursor, copilot, …).
generate_ci_gate_snippet	Emit a GitHub Actions workflow that gates a repo on its agent-tool surface.

Guarantees

• Never executes a scanned MCP server (static analysis only).
• No network on the scan path; deterministic given inputs.
• SAFE means "no blockers observed", not proof of runtime safety.
• UNKNOWN is never treated as safe.

Transport

JSON-RPC 2.0 over stdio (MCP). Zero runtime dependencies — the server is bundled into a single file, consistent with the calllint CLI.

License

Apache-2.0