# Host graphql api with Starlette: Postgres-backed state

Deploy a graphql api built with Starlette 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 Starlette: 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 Starlette: Postgres-backed state
- Where can I host GraphQL API built with Starlette?
- I need a durable state schema and retry/recovery semantics implemented by application code.

## Resource Requirements
- **Compute**
- **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.

## Prerequisites
- A Starlette project that builds and starts with the documented commands (pip install into .ample/python from requirements.txt, then uvicorn from run.py reading PORT on the python-3.12 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**: python-3.12
- **Runtime**: python
- **Size**: s-1vcpu-1gb
- **Install**: python3 -m pip install --target .ample/python -r requirements.txt
- **Start**: PYTHONPATH=.ample/python:${PYTHONPATH:-} python3 run.py

## Workflow Steps
1. ### Build and start  
   `pip install into .ample/python from requirements.txt, then uvicorn from run.py reading PORT on the python-3.12 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).`  
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 --start "python3 run.py"`  
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  --kind build` then `--kind runtime`.`  
   `ample logs  --kind build`

## Success Checks
- **App responds on its public URL**  
  - Kind: http_get  
  - Path: /  
  - Expect: ample canary starlette patterns  
- **Durable-job-state self-test**  
  - Kind: http_get  
  - Path: /p/durable-job-state  
  - Expect: job=done attempts=1 idempotent=true

## Limitations
- Verified on the python-3.12 template at s-1vcpu-1gb with the example fixture; other sizes, templates and Starlette 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.
- 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
- **Currency**: USD  
- **Monthly Amount**: 10.0  
- **Authority**: true  
- **Basis**: size prices from pricing.toml (loaded by the API) at build revision 1ac5595375130d45290090e82ed0f554ccd45405-dirty  
- **Components**:
  - **App server**  
    - Size: s-1vcpu-1gb  
    - Quantity: 1.0  
    - Monthly Amount: 5.0  
  - **Managed PostgreSQL database**  
    - Size: 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. Buckets are allocation-priced per quota and not included.