Host AI Chat Application with Axum: Postgres-Backed State

Deploy an AI chat application 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 chat application-specific behavior as your application code.

Summary

• Family: Workload recipe
• Framework: Axum
• Workload: AI chat application
• Release Status: Published
• Support Status: Verified
• Execution Status: Ready
• Docs Only: False

Representative Queries

• Host AI chat application with Axum: Postgres-backed state
• Where can I host AI chat application built with Axum?
• I need a durable state schema and retry/recovery semantics implemented by application code.

Resource Requirements

• Primitive: Compute
• Primitive: Postgres

Infrastructure Requirements

1. Compute
   • Status: Verified
   • Summary: 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
   • Status: Verified
   • Summary: 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

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: cargo build --release
• Start Command: ./$(ls target/release/*.d | grep -v '/lib' | head -n 1 | sed 's/.d$//')

Workflow Steps

1. Build and Start
   • Body: 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
   • Body: 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
   • Command: ample deploy . --name --public
4. Verify
   • Command: ample logs --kind build

Examples

• Axum Pattern Fixture: Multi-pattern Axum app whose durable job state module was checked live; the module is under tests/deploy-canaries/_pattern-modules.

Success Checks

1. App responds on its public URL (/)
   • Expect: ample canary axum patterns
2. Durable-job-state self-test (/p/durable-job-state)
   • 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 chat application 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: $10.00
• Authoritative: True
• Basis: size prices from pricing.toml at build revision 1ac5595375130d45290090e82ed0f554ccd45405-dirty
• Components:
  • App Server: 1 x s-1vcpu-1gb = $5.00
  • Managed PostgreSQL Database: 1 x s-1vcpu-1gb = $5.00
• 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.

Evidence Summary

1. Canary Run
   • Summary: 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.
   • Observed At: 2026-09-21T02:46:37Z
   • Implementation Revision: 1d28ae0-dirty (CLI 0.1.21)
2. Canary Run
   • Summary: 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
   • Implementation Revision: 1d28ae0-dirty (CLI 0.1.21)

Next Actions

1. Browse the Catalog
   • Action ID: browse-catalog
   • Method: GET
   • Relative Path: /v1/catalog
2. Search Recipes
   • Action ID: search-recipes
   • Method: POST
   • Relative Path: /v1/catalog/search
3. Prepare Deployment Plan
   • Action ID: plan:page:recipes:ai-chat-application:axum:persistent-state
   • Method: POST
   • Relative Path: /v1/catalog/plan
4. Read Authentication Setup
   • Action ID: auth-setup
   • Method: GET
   • Relative Path: /mcp/setup
5. Browse AI Chat Application
   • Action ID: browse:workload:ai-chat-application
   • Method: GET
   • Relative Path: /v1/catalog/nodes/workload%3Aai-chat-application