### Host ai chat application with Axum: streamed responses

#### Summary
Deploy an AI chat application built with Axum on Ample using the streaming response service 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 Server-Sent Events endpoint read incrementally through the public HTTPS gateway: five one-second chunks arrived spread over time with the first within seconds (not buffered), a 70-second stream of 36 chunks completed past common 60-second idle timeouts, and a client that disconnected after two chunks was observed and recorded by the server (disconnected=true). Not separately tested: your event schema, reconnection strategy and any per-request duration ceiling beyond the 70 seconds measured; treat the AI chat application-specific behavior as your application code.

#### Representative Queries
- Host AI chat application with Axum: streamed responses
- Where can I host AI chat application built with Axum?
- I need a tested end-to-end streaming transport, timeout behavior, and client disconnect handling.

#### 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.

#### Framework
Axum

#### Workload
AI chat application

#### Release Status
Published

#### Support Status
Verified

#### Execution Status
Ready

#### Prerequisites
1. 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`.
2. A PostgreSQL driver reading `DATABASE_URL` at runtime (auto-provisioned when omitted, or supplied with --env).
3. An Ample account token with `servers:write`, `databases:read`.

#### Tested Configuration
- **Template:** ubuntu-24.04
- **Runtime:** rust
- **Size:** s-1vcpu-2gb
- **Build Command:** `cargo build --release`
- **Start Command:** `./$(ls target/release/*.d | grep -v '/lib' | head -n 1 | sed 's/\.d$//')`

#### Output Schema
(null)

#### Workflow Steps
1. **Build and start**: `cargo build --release` in the Rust builder image, 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**: 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  --public`
4. **Verify**: Fetch the live URL and the pattern self-test route(s) (/p/streaming-response-service) 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 streaming response service module was checked live.
   - **Source Reference:** tests/deploy-canaries/axum-patterns

#### Success Checks
1. App responds on its public URL
   - Kind: `http_get`
   - Path: `/`
   - Expect: `ample canary axum patterns`
2. Streaming response service self-test
   - Kind: `http_get`
   - Path: `/p/streaming-response-service`
   - Expect: An SSE stream with data.

#### 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 chat application behavior is not separately tested.

#### Cost Estimate
- **Currency:** USD
- **Monthly Amount:** 10.0
- **Note:** Always-on monthly price of the tested sizes; apps and databases auto-pause when idle.

#### Evidence Summary
1. **Canary run:** Axum pattern fixture deployed on Ample; checks passed for streaming-response-service and configuration-secrets.
   - **Observed At:** 2026-09-21T02:46:37Z
2. **Canary run:** The same Axum app deployed with a --release-command migration; the marker it created was readable after activation.
   - **Observed At:** 2026-09-21T02:46:37Z

#### Last Verified At
2026-09-21T02:46:37Z