# Host REST API with NestJS: Streamed Responses

## Summary
Deploy a REST API built with NestJS 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 NestJS: 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 REST API-specific behavior as your application code.

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

## Prerequisites
- A NestJS project that builds and starts with the documented commands (npm install, nest build (TypeScript) then node dist/main.js 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`, `nest build (TypeScript)` then `node dist/main.js` 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.
3. **Deploy**: Run the synchronous deploy once and read the result.
4. **Verify**: Fetch the live URL and the pattern self-test route(s).

## Examples
- **NestJS Pattern Fixture**: Multi-pattern NestJS app whose streaming response service module was checked live.

## Cost Estimate
- **Monthly Amount**: $10.00
- **Components**:
  - App server size: 1 vCPU 1 GB, quantity: 1.0, monthly amount: $5.00
  - Managed PostgreSQL database size: 1 vCPU 1 GB, quantity: 1.0, monthly amount: $5.00

## Limitations
- Verified on the node-22 template at s-1vcpu-1gb.
- The REST API itself is application code and was not separately tested.

## Success Checks
- App responds on its public URL
- Streaming-response-service self-test.