### Host ai workflow runner with NestJS: worker execution and job state

Deploy a ai workflow runner built with NestJS 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 NestJS: 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 NestJS: worker execution and job state
- Where can I host AI workflow runner built with NestJS?
- I need a separately runnable worker, durable job records and idempotent retries; not a managed queue.

#### 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.

#### Prerequisites
1. 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, nest build (TypeScript) then node dist/main.js on the node-22 template; the worker starts with node worker (its own package.json start script) and binds no port)
2. 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
3. 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`

#### 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 NestJS 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-queue check is what was verified.
- The worker service is private: it has no public URL and is reached only through the shared database; both services are placed with their database.

#### Cost Estimate
- **Currency**: USD  
- **Monthly Amount**: 15.0  
- **Note**: Always-on monthly price of the tested sizes for the web service, the worker service and the database; apps auto-pause when idle.

#### Examples
- **NestJS web + worker fixture**  
  A NestJS 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.

#### Evidence Summary
- **Kind**: canary_run  
  **Summary**: NestJS web service plus a separate NestJS worker process deployed on Ample with `ample plan --write` then `ample up` (npm install, nest build (TypeScript) then node dist/main.js on the node-22 template); the web service enqueued a job that the private worker service consumed from the shared managed PostgreSQL database.  
  **Observed At**: 2026-09-20T03:56:46Z
  **Expires At**: 2027-03-19T03:56:46Z

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