## Host GraphQL API with Axum: Stored Input and Output Artifacts

### Summary
Deploy a GraphQL API built with Axum on Ample using the generated downloads 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`, a private S3-compatible bucket holds objects with credentials delivered as encrypted environment variables. Verified on Axum: an export query rendered to a CSV artifact stored with metadata in a private bucket and returned only to an authorized caller (401 without token, export=ok rows=3). Not separately tested: your export formats, retention policy and entitlement model; treat the GraphQL API-specific behavior as your application code.

### Representative Queries
- Host GraphQL API with Axum: stored input and output artifacts
- Where can I host GraphQL API built with Axum?
- I need an input/output artifact contract, object metadata, and access boundaries.

### Resource Requirements
- primitive:compute
- primitive:postgres
- primitive:s3-compatible-object-storage

### 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.
3. **S3-compatible Object Storage**  
   Buckets are S3-compatible with issued credentials; PutObject and GetObject are verified by canary. Other S3 operations are not verified.

### Prerequisites
- An Axum project that builds and starts with the documented commands (`cargo build --release` in the rust builder image (stable toolchain, Cargo.lock committed, pure-Rust dependencies), then the release binary on the `ubuntu-24.04` template reading `PORT` and `DATABASE_URL`).
- A PostgreSQL driver reading `DATABASE_URL` at runtime (auto-provisioned when omitted, or supplied with `--env`).
- A bucket from `ample bucket create` with its credentials passed as encrypted `S3_*` environment variables.
- An Ample account token with `servers:write`, `databases:read`, `buckets:read`.

### Workflow Steps
1. **Build and Start**  
   `cargo build --release` in the rust builder image (stable toolchain, Cargo.lock committed, pure-Rust dependencies), then the release binary on the `ubuntu-24.04` template reading `PORT` and `DATABASE_URL`. The server must bind `0.0.0.0` on `PORT`.
2. **Implement the Pattern on PostgreSQL**  
   The fixture's module implements generated downloads: an export query rendered to a CSV artifact stored with metadata in a private bucket and returned only to an authorized caller (401 without token, export=ok rows=3). Copy the approach into your schema; keep migrations idempotent and run them with `--release-command`.
3. **Wire Object Storage**  
   Create the bucket(s), then pass endpoint, region, bucket and keys as `--env` values. Use path-style addressing. Keep private data in an unpublished bucket.
4. **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 --env S3_ENDPOINT=... --env S3_REGION=... --env S3_BUCKET=... --env S3_ACCESS_KEY_ID=... --env S3_SECRET_ACCESS_KEY=...`.
5. **Verify**  
   Fetch the live URL and the pattern self-test route(s) (`/p/generated-downloads`) from the example; then run your own checks. On failure read `ample logs  --kind build` then `--kind runtime`.  
   Command: `ample logs  --kind build`.

### Examples
- **Axum Pattern Fixture**  
  Multi-pattern Axum app whose generated downloads module was checked live; the module is under `tests/deploy-canaries/_pattern-modules`.  
  Source reference: `tests/deploy-canaries/axum-patterns`.

### Success Checks
1. App responds on its public URL: `HTTP GET /` (expect: `ample canary axum patterns`).
2. Generated-downloads self-test: `HTTP GET /p/generated-downloads` (expect: `export=ok rows=3 (with ?token=...; 401 without)`).

### Limitations
- Verified on the `ubuntu-24.04` template at `s-1vcpu-2gb` with the example fixture; other sizes, templates, and Axum major versions are not verified.
- The GraphQL API itself (your export formats, retention policy and entitlement model) 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.
- PutObject and GetObject with path-style addressing are verified; multipart upload, listing, presigned URLs, and lifecycle rules are not verified.

### Cost Estimate  
Currency: **USD**  
Monthly Amount: **10.0**  
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.