hello-worker

hello-worker (TypeScript)

Minimal canonical WCP worker in TypeScript.

Capability: cap.hello.greet Species: wrk.hello.greeter Worker ID: org.example.hello-greeter Risk tier: low

---

What it does

Takes an optional name field and returns a greeting. Simple by design — the focus is the worker contract, not the business logic.

Input:

{
  "name": "Alice",
  "correlation_id": "test-123",
  "tenant_id": "demo",
  "capability_id": "cap.hello.greet"
}

Output (WorkerResult):

{
  "status": "ok",
  "result": {
    "greeting": "Hello, Alice!",
    "name": "Alice",
    "worker_id": "org.example.hello-greeter"
  },
  "telemetry": [
    {
      "event_id": "evt.worker.executed.v1",
      "timestamp": "...",
      "correlation_id": "test-123",
      "tenant_id": "demo",
      "worker_id": "org.example.hello-greeter",
      "worker_species_id": "wrk.hello.greeter",
      "capability_id": "cap.hello.greet",
      "status": "ok"
    }
  ],
  "evidence": [
    {
      "correlation_id": "test-123",
      "dispatched_at": "...",
      "worker_id": "org.example.hello-greeter",
      "capability_id": "cap.hello.greet",
      "policy_decision": "ALLOW",
      "controls_verified": ["ctrl.obs.audit-log-append-only"],
      "artifact_hash": "sha256:..."
    }
  ]
}

---

Run

Build the SDK first (from the sdk/typescript/ root):

npm run build

Then run the worker directly:

# Pass request as a CLI argument
node dist/workers/examples/hello-worker/worker.js '{"name": "Alice", "correlation_id": "test-123", "tenant_id": "demo"}'

# Default (name defaults to "World")
node dist/workers/examples/hello-worker/worker.js

# stdio mode — pipe JSON in, get JSON out
echo '{"name": "Alice"}' | node dist/workers/examples/hello-worker/worker.js --stdio

---

Enroll

pyhall enroll registry-record.json --registry-dir enrolled/

registry-record.json declares:

• worker_id: org.example.hello-greeter
• capabilities: ["cap.hello.greet"]
• risk_tier: low
• allowed_environments: ["dev", "stage", "prod"]
• required_controls / currently_implements: ["ctrl.obs.audit-log-append-only"]
• blast_radius: all zeros, reversibility: reversible

---

Worker contract

This worker follows the canonical WCP worker pattern:

• execute(request) accepts a plain object, returns a WorkerResult.
• Never throws — all errors are returned as status: "error".
• Emits evt.worker.executed.v1 in telemetry.
• Produces an evidence receipt with artifact_hash (SHA-256 of the canonicalized request).
• correlation_id propagates through all telemetry and evidence fields.

Use this as a template for your own TypeScript workers.