page:recipes:ai workflow runner:nestjs:worker state

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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