## Host graphql api with Fastify: streamed responses

Deploy a graphql api built with Fastify on Ample using the streaming response service pattern. Compute runs the app in an isolated microVM behind a public HTTPS URL, a managed PostgreSQL 16 database is auto-provisioned and injected as DATABASE_URL. Verified on Fastify: a Server-Sent Events endpoint read incrementally through the public HTTPS gateway: five one-second chunks arrived spread over time with the first within seconds (not buffered), a 70-second stream of 36 chunks completed past common 60-second idle timeouts, and a client that disconnected after two chunks was observed and recorded by the server (disconnected=true). Not separately tested: your event schema, reconnection strategy and any per-request duration ceiling beyond the 70 seconds measured; treat the graphql api-specific behavior as your application code.

### Representative Queries
- Host graphql api with Fastify: streamed responses
- Where can I host GraphQL API built with Fastify?
- I need a tested end-to-end streaming transport, timeout behavior and client disconnect handling.

### Prerequisites
- A Fastify project that builds and starts with the documented commands (npm install, npm run build --if-present, npm run start on the node-22 template)
- A PostgreSQL driver reading DATABASE_URL at runtime (auto-provisioned when omitted, or supplied with --env)
- An Ample account token with servers:write, databases:read

### Workflow Steps
1. **Build and start**  
   `npm install, npm run build --if-present, npm run start on the node-22 template. The server must bind 0.0.0.0 on PORT.`

2. **Implement the pattern on PostgreSQL**  
   The fixture's module implements streaming response service: a Server-Sent Events endpoint read incrementally through the public HTTPS gateway: five one-second chunks arrived spread over time with the first within seconds (not buffered), a 70-second stream of 36 chunks completed past common 60-second idle timeouts, and a client that disconnected after two chunks was observed and recorded by the server (disconnected=true). Copy the approach into your schema; keep migrations idempotent and run them with --release-command.
   
3. **Deploy**  
   Run the synchronous deploy once and read the result (exit 0 live, 1 failed, 2 blocked). Re-running with no change is a no-op.  
   Command: `ample deploy . --name <your-app-name> --public`
   
4. **Verify**  
   Fetch the live URL and the pattern self-test route(s) (/p/streaming-response-service) from the example; then run your own checks. On failure read `ample logs --kind build` then `--kind runtime`.  
   Command: `ample logs --kind build`

### Examples
- **Fastify pattern fixture**: Multi-pattern Fastify app whose streaming response service module was checked live; the module is under tests/deploy-canaries/_pattern-modules. Source Ref: `tests/deploy-canaries/fastify-patterns`

### Success Checks
- **App responds on its public URL**: Expect an HTTP GET on `/` to return `ample canary fastify patterns`.
- **Streaming-response-service self-test**: Expect an HTTP GET on `/p/streaming-response-service` to return an SSE stream.

### Limitations
- Verified on the node-22 template at s-1vcpu-1gb with the example fixture; other sizes, templates, and Fastify major versions are not verified.
- The graphql api itself is application code and was not separately tested; the pattern checks are verified.

### Cost Estimate
- **Currency**: USD
- **Monthly Amount**: 10.0
- **Components**:
  - App server: `s-1vcpu-1gb`, Quantity: 1.0, Monthly Amount: 5.0
  - Managed PostgreSQL database: `s-1vcpu-1gb`, Quantity: 1.0, Monthly Amount: 5.0
  - Note: Always-on monthly price of the tested sizes; apps and databases auto-pause when idle.

### Additional Resources
- **HTML Documentation**: [Link](/content/recipes/graphql-api/fastify/response-streaming/index.html)
- **Markdown Documentation**: [Link](/content/recipes/graphql-api/fastify/response-streaming.md)
- **JSON Documentation**: [Link](https://api.ample.computer/v1/catalog/recipes/page%3Arecipes%3Agraphql-api%3Afastify%3Aresponse-streaming)