# Host ai workflow runner with Axum: Postgres-backed state

## Summary

Deploy a ai workflow runner built with Axum 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 Axum: 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 ai workflow runner-specific behavior as your application code.

## Infrastructure requirements

- Compute: verified (Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.)  
- Postgres: verified (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 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)
- An Ample account token with servers:write, databases:read

## 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 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.
   
   ```
   ample deploy . --name <app-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 <deployment_id> --kind build` then `--kind runtime`.
   
   ```
   ample logs <deployment_id> --kind build
   ```

## Success checks

- app responds on its public URL (`/` on the live URL, expect ample canary axum patterns)
- durable-job-state self-test (`/p/durable-job-state` on the live URL, expect job=done attempts=1 idempotent=true)

## 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 ai workflow runner 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

Estimated 10.00 USD per month.
- app server x1 `s-1vcpu-1gb`: 5.00 USD
- managed PostgreSQL database x1 `s-1vcpu-1gb`: 5.00 USD

Always-on monthly price of the tested sizes; apps and databases auto-pause when idle. Buckets are allocation-priced per quota and not included.

## Verification evidence

- canary_run on 2026-09-21T02:46:37Z at revision `1d28ae0-dirty (CLI 0.1.21)`: Axum pattern fixture deployed on Ample (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); checks passed for durable-job-state and configuration-secrets. Pattern proof: 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). (expires 2027-03-20T02:46:37Z)
- canary_run on 2026-09-21T02:46:37Z at revision `1d28ae0-dirty (CLI 0.1.21)`: The same Axum app deployed with a --release-command migration; the marker it created was readable after activation. (expires 2027-03-20T02:46:37Z)

Last verified: 2026-09-21T02:46:37Z

## Execution binding

MCP tool `ample_deploy`, binding state `current`, required scopes: servers:write, databases:read.