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Fastify Server Adapter Example

examples/server-fastify-adapter/README.md

2025-12-181.2 KB
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Fastify Server Adapter Example

This example demonstrates how to use the @mastra/fastify server adapter to run Mastra with Fastify.

What it shows

  • Basic server setup with MastraServer
  • Custom routes added after init() with access to Mastra context
  • Accessing the Mastra instance via request.mastra

Getting started

  1. Install dependencies:
bash
pnpm install
  1. Copy .env.example to .env and add your OpenAI API key:
bash
cp .env.example .env
  1. Start the server:
bash
pnpm start

Testing the endpoints

List agents:

bash
curl http://localhost:4111/api/agents

Health check (custom route):

bash
curl http://localhost:4111/health

Generate a response:

bash
curl -X POST http://localhost:4111/api/agents/assistantAgent/generate \
  -H "Content-Type: application/json" \
  -d '{"messages": "What is 2+2?"}'

Key differences from Express/Hono

  • Fastify has built-in JSON body parsing, no middleware needed
  • Context is accessed via request.mastra (extended Fastify request)
  • Fastify uses async handlers by default

Documentation