## Host AI Workflow Runner with Fastify: Worker Execution and Job State

### Summary
Deploy an AI workflow runner built with Fastify 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 Fastify: 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 workflow runner-specific behavior as your application code.

### Representative Queries
- Host AI workflow runner with Fastify: worker execution and job state
- Where can I host AI workflow runner built with Fastify?
- I need a separately runnable worker, durable job records and idempotent retries; not a managed queue.

### Resource Requirements
- Compute
- Postgres

### Prerequisites
- A repository with the web app and the worker as separate service directories (the fixture uses apps/web and apps/worker), each building and starting with the documented commands (npm install, npm run build --if-present, npm run start on the node-22 template; the worker starts with node worker (its own package.json start script) and binds no port)
- Both services read DATABASE_URL at runtime and share one jobs table; the worker claims rows with SELECT ... FOR UPDATE SKIP LOCKED and marks them done once
- An Ample account token with servers:write and databases:write (ample up creates the database)

### Workflow Steps
#### 1. Plan the topology
Run the planner once. It discovers the web and worker services, infers kind = "worker" for the process without a port, declares the database each service needs, and writes ample.toml. Exit 2 means it left questions in the manifest; answer them with --answer or by editing the file.

Command: `ample plan --write .`

#### 2. Share one database
Keep a single [databases.main] with engine = "postgres", drop any per-service database the planner added, and set DATABASE_URL = { database = "main" } under both [services.web.env] and [services.worker.env].

Command: `ample plan --offline .`

#### 3. Apply
Reconcile the whole manifest in dependency order: the database first, then both services. It is idempotent and never destructive; exit 0 means everything applied, 2 needs input, 1 a failed resource (independent siblings still proceed and re-running resumes).

Command: `ample up .`

#### 4. Verify
Fetch the web service URL and its worker status route (/p/worker-queue/status in the example) and confirm the worker processed the enqueued job; on failure read the worker service's runtime logs.

Command: `ample logs  --kind runtime`

### Examples
#### Fastify Web + Worker Fixture
- Description: A Fastify web app (apps/web) and a worker process (apps/worker) sharing one managed PostgreSQL database; the queue module is under tests/deploy-canaries/_pattern-modules.
- Source Reference: tests/deploy-canaries/fastify-worker

### Success Checks
- Web service responds on its public URL
- Worker consumed the enqueued job

### Limitations
- Verified on the node-22 template at s-1vcpu-1gb for both services with the example fixture; other sizes, templates and Fastify major versions are not verified.
- The AI workflow runner itself (your job payloads, retry policy and scheduling) is application code and was not separately tested.
- The worker is a single long-running process supervised in its own microVM; there is no scheduler, cron or horizontal worker scaling in this recipe.

### Cost Estimate
- Currency: USD
- Monthly Amount: 15.0
- Components:
  - Web Server: size s-1vcpu-1gb; quantity: 1.0; monthly amount: 5.0
  - Worker Server: size s-1vcpu-1gb; quantity: 1.0; monthly amount: 5.0
  - Managed PostgreSQL Database: size s-1vcpu-1gb; quantity: 1.0; monthly amount: 5.0
- Note: Always-on monthly price of the tested sizes for the web service, the worker service and the database; apps auto-pause when idle.

### Evidence Summary
- Summary: Fastify web service plus a separate Fastify worker process deployed on Ample with `ample plan --write` then `ample up`.
- Observed At: 2026-09-20T03:56:46Z
- Implementation Revision: 03b6402b1b3e19178985f08ea4033804521d85d4-dirty.

### Last Verified At
2026-09-20T03:56:46Z

### Formats
- HTML: https://ample.computer/recipes/ai-workflow-runner/fastify/worker-state
- Markdown: https://ample.computer/recipes/ai-workflow-runner/fastify/worker-state.md
- JSON: https://api.ample.computer/v1/catalog/recipes/page%3Arecipes%3Aai-workflow-runner%3Afastify%3Aworker-state

### Next Actions
#### Browse the catalog index
- Operation ID: catalog_index

#### Search published recipes by intent, stack and constraints
- Operation ID: search_recipes

#### Prepare a side-effect-free deployment plan for an authorized project
- Operation ID: plan_deployment

#### Read the existing agent authentication setup
- Operation ID: existing_auth_setup

#### Browse AI workflow runner
- Operation ID: browse_node

#### Browse Fastify
- Operation ID: browse_node

#### Browse Dedicated worker process
- Operation ID: browse_node

#### Browse Deploy AI app
- Operation ID: browse_node