## Host mobile backend with Gin: streamed responses

Deploy a mobile backend built with Gin 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 Gin: 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 mobile backend-specific behavior as your application code.

### Representative Queries
- Host mobile backend with Gin: streamed responses
- Where can I host Mobile backend built with Gin?
- 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. (Verified)
- **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. (Verified)

### Prerequisites
- A Gin project that builds and starts with the documented commands (`CGO_ENABLED=0 go build -o app ./...` then `./app` on the ubuntu-24.04 template (go.sum committed for a reproducible build))
- 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**: `CGO_ENABLED=0 go build -o app ./...` then `./app` on the ubuntu-24.04 template (go.sum committed for a reproducible build). 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 --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`

### Limitations
- Verified on the ubuntu-24.04 template at s-1vcpu-1gb with the example fixture; other sizes, templates and Gin major versions are not verified.
- The mobile backend 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.
- Region, compliance attestations and request-duration limits are unknown and not claimed.
- Apps auto-pause when idle and wake on the next request; always-on is an operator setting, not a plan feature.
- Managed PostgreSQL 16 only; extensions, connection limits and backup or restore procedures are not verified; apps and their databases are placed together.

### Cost Estimate
- **Monthly Amount**: $10.00 USD
  - Components:
    - App server: 1.0 x s-1vcpu-1gb = $5.00
    - Managed PostgreSQL database: 1.0 x s-1vcpu-1gb = $5.00
  - Note: Always-on monthly price of the tested sizes; apps and databases auto-pause when idle.

### Next Actions
- **[Browse the catalog index]()** 
- **[Search published recipes by intent, stack and constraints]()** 
- **[Prepare a side-effect-free deployment plan for an authorized project]()** 
- **[Read the existing agent authentication setup]()** 
- **[Browse Mobile backend]()** 
- **[Browse Gin]()** 
- **[Browse Streaming response service]()** 
- **[Browse Deploy API]()**

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