# Host GraphQL API with Express: Postgres-backed State

Deploy a GraphQL API built with Express on Ample using the durable job state 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 jobs table with a state and attempts counter, processing inside a row-locked transaction, and a second run that is a no-op (job=done attempts=1 idempotent=true). Not separately tested: your job types, payload schema and retry policy; treat the GraphQL API-specific behavior as your application code.

## Representative Queries
- Host GraphQL API with Express: Postgres-backed state
- Where can I host GraphQL API built with Express?
- I need a durable state schema and retry/recovery semantics implemented by application code.

## Resource Requirements
- Compute
- Postgres

## Infrastructure Requirements
1. **Compute**: Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.
2. **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.

## 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

## 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 durable job state: a jobs table with a state and attempts counter, processing inside a row-locked transaction, and a second run that is a no-op (job=done attempts=1 idempotent=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 <name> --public`
4. **Verify**: Fetch the live URL and the pattern self-test route(s) (/p/durable-job-state) from the example; then run your own checks. On failure read `ample logs <deploymentId> --kind build` then `--kind runtime`.

## Examples
- **Express pattern fixture**: Multi-pattern Express app whose durable job state module was checked live; the module is under tests/deploy-canaries/_pattern-modules. Source: tests/deploy-canaries/express-patterns

## Success Checks
1. app responds on its public URL (http_get - /)
2. durable-job-state self-test (http_get - /p/durable-job-state)

## 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 job types, payload schema and retry policy) is application code and was not separately tested; the pattern checks are what was verified.

## Cost Estimate
- **Monthly Amount**: $10.00 (USD)
- **Components**: 
  - App server (s-1vcpu-1gb): $5.00
  - Managed PostgreSQL database (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](https://api.ample.computer/v1/catalog)
- [Search published recipes](https://api.ample.computer/v1/catalog/search)
- [Prepare a side-effect-free deployment plan](https://api.ample.computer/v1/catalog/plan)