Fly.io MCP: Documentation

Connection

fly mcp server — a command built into flyctl (needs an installed and authorized copy: fly auth login). Supports three transports: stdio (default, for local MCP clients), SSE and HTTP (for remote setups). No separate API key needed — the server uses the current CLI session. See fly.io/docs/mcp for details.

Tools

Tools are grouped around Fly.io's core entities:

• Apps — list, status, configuration (fly.toml), deploy.
• Machines — list, create, stop, restart individual Firecracker VMs.
• Certificates — view and add TLS certificates for app domains.
• Logs — view an app's logs for a chosen time window.
• Volumes — view and manage persistent storage volumes.

Agent flow

"Which Machines are running for my-app, and in what region?", "show my-app's logs from the last 15 minutes", "add a TLS certificate for the domain api.example.com", "how much space is used on the database volume?".

Pricing

The MCP server is free (part of flyctl); Fly.io resources (Machines, volumes, traffic) are billed per the platform's usual usage-based plan.