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

### Summary
Deploy a ai workflow runner built with NestJS 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 NestJS: 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.

### Framework
NestJS

### Workload
AI workflow runner

### Release Status
Published

### Support Status
Verified

### Execution Status
Ready

### Prerequisites
- A NestJS project that builds and starts with the documented commands (npm install, nest build (TypeScript) then node dist/main.js on the node-22 template)
- 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

### Tested Configuration
- **Template:** node-22
- **Runtime:** node
- **Size:** s-1vcpu-1gb
- **Install:** npm install
- **Build:** npm run build --if-present
- **Start:** npm run start

### Workflow Steps
1. **Build and start**  
   `npm install, nest build (TypeScript) then node dist/main.js on the node-22 template. 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**  
   `ample deploy . --name  --public`  
   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.

4. **Verify**  
   `ample logs  --kind build`  
   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 the logs.

### Success Checks
- **App responds on its public URL**  
  Kind: `http_get`
  Path: `/`
  Expect: `ample canary nestjs patterns`

- **Durable-job-state self-test**  
  Kind: `http_get`
  Path: `/p/durable-job-state`
  Expect: `job=done attempts=1 idempotent=true`

### Limitations
- Verified on the node-22 template at s-1vcpu-1gb with the example fixture; other sizes, templates and NestJS 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.

### 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: s-1vcpu-1gb, Quantity: 1.0, Monthly Amount: 5.0
  - Managed PostgreSQL database: s-1vcpu-1gb, Quantity: 1.0, Monthly Amount: 5.0

### Evidence Summary
1. **Canary Run**  
   Summary: NestJS pattern fixture deployed on Ample (npm install, nest build (TypeScript) then node dist/main.js on the node-22 template); checks passed for durable-job-state and configuration-secrets.  
   Observed At: `2026-09-21T02:34:39Z`

2. **Canary Run**  
   Summary: The same NestJS app deployed with a --release-command migration; the marker it created was readable after activation.  
   Observed At: `2026-09-20T02:16:51Z`

### Next Actions
- **Browse the catalog index**
    - Method: `GET`
    - Path: `/v1/catalog`

- **Search published recipes by intent, stack and constraints**
    - Method: `POST`
    - Path: `/v1/catalog/search`
    - Body: {"limit":5,"query":"Host ai workflow runner with NestJS: Postgres-backed state"}

- **Prepare a side-effect-free deployment plan for an authorized project**
    - Method: `POST`
    - Path: `/v1/catalog/plan`  
    - Body: {"inputs":{},"projectId":"","recipeId":"page:recipes:ai-workflow-runner:nestjs:persistent-state","recipeRevision":"r1"}