# Host ai chat application with Axum: worker execution and job state

## Summary

Deploy a ai chat application built with Axum as a public web service plus a dedicated worker process on Ample. `ample plan --write` discovers both services and their shared database and writes ample.toml; `ample up` reconciles the topology: a managed PostgreSQL 16 database, a public web microVM and a private worker microVM (kind worker, no public URL), both reading DATABASE_URL. Verified on Axum: a separately deployed worker service (kind worker, no public URL) sharing a declared managed PostgreSQL database with the web service, consuming a jobs table with row locks and marking jobs done once (worker=done attempts=1). Not separately tested: your job payloads, retry policy and scheduling; treat the ai chat application-specific behavior as your application code.

## Infrastructure requirements

- Confirmed isolated x86_64 Firecracker microVMs for computing.
- Verified managed PostgreSQL 16 runs in its own microVM and is auto-provisioned when needed.

## Prerequisites

- A repository with the web app and the worker as separate service directories.
- Both services read DATABASE_URL at runtime and share one jobs table.
- An Ample account token with servers:write and databases:write.

## Exact tested configuration

- template: `ubuntu-24.04`
- runtime: `rust`
- size: `s-1vcpu-2gb`
- build: `cargo build --release`
- start: `./$(ls target/release/*.d | grep -v '/lib' | head -n 1 | sed 's/\.d$//')`

## Steps

1. **Plan the topology.** Run the planner once.
   ```
   ample plan --write .
   ```
2. **Share one database.** Keep a single [databases.main] with engine = "postgres".
   ```
   ample plan --offline .
   ```
3. **Apply.** Reconcile the manifest in dependency order.
   ```
   ample up .
   ```
4. **Verify.** Fetch the web service URL and its worker status route.
   ```
   ample logs <deployment_id> --kind runtime
   ```

## Tested examples

- **Axum web + worker fixture.** A Axum web app and a worker process sharing one managed PostgreSQL database.

## Success checks

- Web service responds on its public URL.
- Worker consumed the enqueued job.

## Limitations

- Verified on the ubuntu-24.04 template at s-1vcpu-2gb for both services.
- The ai chat application’s behavior and specifics were not separately tested.
- The worker is a single long-running process with no horizontal scaling.

## Cost estimate

Estimated 15.00 USD per month.
- web server x1 `s-1vcpu-1gb`: 5.00 USD
- worker server x1 `s-1vcpu-1gb`: 5.00 USD
- managed PostgreSQL database x1 `s-1vcpu-1gb`: 5.00 USD

## Verification evidence

- canary_run on 2026-09-21T02:46:37Z: Axum web service plus a separate Axum worker process deployed on Ample.

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

## Execution binding

MCP tool `ample_up`, schema hash `db7ca0facfe2cd28`.