FastMCP

In this catalog it is the Agentic Gateways option when you need to front agents and MCP/tool surfaces safely. Keep FastMCP on the observe/propose side of the loop: useful signals and drafts, with human or policy authority still required before anything irreversible runs.

Clients connect to the gateway/registry; it authenticates, discovers MCP/agent servers, and proxies tool or agent traffic under configured policy.

1. Register or discover the MCP/agent servers the gateway will front.
2. Configure authn/z and allow-lists for tools.
3. Proxy a tool call from a test agent and verify policy denials.
4. Cut agent runtimes over to the gateway endpoint.

Related: model-context-protocol · mcp-servers-reference · topics/33-skill-registry · topics/12-central-nervous-system

• Use when: FastMCP is a high-level Python framework for building, composing, testing, authenticating, and deploying MCP servers and clients with decorators and generated schemas matches the bottleneck and you specifically need to front agents and MCP/tool surfaces safely.
• Skip when: another pack already covers the need with less ops surface, or FastMCP would become a second place people retype truth.
• Prefer instead: compare Model Context Protocol, MCP Servers (reference) before locking the cell.

• Ops: confirm license, hosting, and release cadence for FastMCP (PrefectHQ/fastmcp) before relying on it in a live corridor.
• Integration: bad credentials, scopes, or schema drift produce empty retrievals or runaway tool/model spend without an obvious UI alarm.
• Scope: Agentic Gateways components support agents; they are not the company ledger or the approval authority.