## Host graphql api with Express: streamed responses

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

### Resource Requirements
- primitive:compute
- primitive:postgres

### Infrastructure Requirements
- **Compute**: Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.
- **Postgres**: Managed PostgreSQL 16 runs in its own microVM and is auto-provisioned when an app needs a database and no DATABASE_URL is supplied.

### Framework
Express  
### Workload
GraphQL API
### Release Status
published  
### Support Status
verified  
### Execution Status
ready  
### Prerequisites
- A Express 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

### Tested Configuration
- **Template**: node-22
- **Runtime**: node
- **Size**: s-1vcpu-1gb
- **Install**: npm install
- **Build**: npm run build --if-present
- **Start**: npm run start

### 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. `ample deploy . --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`. `ample logs --kind build`

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

### Success Checks
- app responds on its public URL
- streaming-response-service self-test

### Limitations
- Verified on the node-22 template at s-1vcpu-1gb with the example fixture; other sizes, templates and Express major versions are not verified.
- The graphql api itself (your event schema, reconnection strategy and any per-request duration ceiling beyond the 70 seconds measured) is application code and was not separately tested; the pattern checks are what was verified.

### Cost Estimate
- **Currency**: USD
- **Monthly Amount**: 10.0
- **Components**:
  - **app server**: s-1vcpu-1gb (quantity: 1.0) - $5.0
  - **managed PostgreSQL database**: s-1vcpu-1gb (quantity: 1.0) - $5.0

### Evidence Summary
- **Express pattern fixture deployed on Ample**: The checks passed for streaming-response-service and configuration-secrets. Pattern proof: 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).

### Next Actions
1. **Browse the catalog index**
2. **Search published recipes by intent, stack and constraints**
3. **Prepare a side-effect-free deployment plan for an authorized project**
4. **Read the existing agent authentication setup**
5. **Browse GraphQL API**
6. **Browse Express**
7. **Browse Streaming response service**
8. **Browse Deploy API**