fastify-mcp-serverCAUTION
Wire MCP protocol in your Fastify applications with ease
Overview
From the repository's own README, as read at the audited commit. Badges and raw HTML are left out.
A Fastify plugin for building Model Context Protocol (MCP) servers aligned with the 2026-07-28 specification over Streamable HTTP or native stdio.
The plugin provides a thin Fastify-native integration around the MCP TypeScript SDK v2. The Streamable HTTP transport is request-stateless: MCP requests are processed independently, with no initialize handshake, no Mcp-Session-Id, no protocol session store, and no transport affinity between requests. The stdio transport delegates the connection to the SDK's native serveStdio entry.
[](https://www.npmjs.com/package/fastify-mcp-server) [](https://www.npmjs.com/package/fastify-mcp-server) [](https://github.com/flaviodelgrosso/fastify-mcp-server/actions/workflows/ci.yml) [](https://codecov.io/gh/flaviodelgrosso/fastify-mcp-server)
Table of Contents
- Fastify MCP Server Plugin
- Table of Contents
- Overview
- Features
- Core Functionality
- Advanced Features
- Installation
- Quick Demo
- Quick Start
- Streamable HTTP and stdio
- API Reference
- Plugin Options
- MCP Decorator
- Transports
- Transport Selection
- Lifecycle
- Logging and stdout Safety
- HTTP and stdio Differences
- [HTTP Protocol](#http-proto
c84aba3cb8a3OBSERVED · 2026-10-12Connect
Built from this server's own package name, version and transport as found in its source — not copied from anyone's documentation, so it cannot drift against a page we do not control.
claude mcp add fastify-mcp-server -- npx -y [email protected]
{
"mcpServers": {
"fastify-mcp-server": {
"command": "npx",
"args": [
"-y",
"[email protected]"
]
}
}
}Exposed tools (7)
7 read · 0 write · 0 destructive.
| Tool | Risk | Description |
|---|---|---|
confirm | read | |
deployment-name | read | |
echo | read | |
example-auth-tool | read | |
get-datetime | read | |
regional | read | |
wait | read |
Trust audit
CAUTIONgrade B · trust 87/100 Install with care. The audit found things worth knowing before you trust its output.
| Layer | What it checks | Result |
|---|---|---|
| L0 | Provenance & inventory | PASS |
| L1 | Static analysis of the code | WARN |
| L2 | Instruction surface (what it tells the agent) | PASS |
| L3 | Class-specific surface | WARN |
| L4 | Behavioural (sandbox) | SKIPPED |
What the source does
- Filesystem
- declared (3 observation(s))
- Network
- declared (4 observation(s))
- Shell
- none-observed
- Dependencies
- not all pinned
- Secrets in source
- none-found
Findings (11)
authorization_endpoint: 'http://127.0.0.1:9080/authorize',
issuer: 'http://127.0.0.1:9080',
token_endpoint: 'http://127.0.0.1:9080/token'
resourceServerUrl: new URL('http://127.0.0.1:9080/mcp'),streamable-http
.commitlintrc
import packageJson from '../../package.json' with { type: 'json' };import FastifyMcpServer from '../../src/index.ts';
import type { FastifyMcpServerOptions } from '../../src/types.ts';import FastifyMcpServer from '../../src/index.ts';
@modelcontextprotocol/node, fastify-plugin, @commitlint/cli, @commitlint/config-conventional, @fastify/autoload, @fastify/cors, @fastify/formbody, @modelcontextprotocol/client
Gates applied: no_behavioural_pass.
c84aba3cb8a3full audit observations/trust-audit/mcp-server/flaviodelgrosso__fastify-mcp-server.json · Report an issue / request a re-scanAudit history
Every audit this server has had. A grade with a past is a grade somebody is still checking.
| Date | Source | Verdict | Grade | Score | Change |
|---|---|---|---|---|---|
| 2026-10-12 | c84aba3cb8a3 | CAUTION | B | 87 | first audit |
Questions
What is the fastify-mcp-server MCP server?
Wire MCP protocol in your Fastify applications with ease
What tools does fastify-mcp-server expose?
7 in total: 7 read-only, 0 that write, and 0 that can delete or overwrite. Every one is listed on this page with its risk.
Is fastify-mcp-server safe to connect to an agent?
With care. The audit graded it B (87/100) and found 11 things worth knowing before you trust this server, listed below with the exact line each was found on.
What credentials does fastify-mcp-server need?
No credential environment variables were found in its source, so it appears to need none.
How does fastify-mcp-server run?
It speaks streamable-http, so it runs as a service you connect to over the network. It is published on npm as fastify-mcp-server at 1.1.0.
How current is this page?
The grade is for one exact copy of the source (c84aba3cb8a3), read on 2026-10-12. The repository is watched and re-audited when it changes.