> ## Documentation Index
> Fetch the complete documentation index at: https://headgate.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Send control to a worker on its next heartbeat.

> Faktory's BEAT carries quiet/terminate; here it is one column on the worker row,
read back by the heartbeat upsert. The list endpoint separates the pending
command from the worker-acknowledged status. `quiet` pauses admission (in-flight work
finishes), `resume` resumes, `terminate` shuts the worker down gracefully, and
`resign` releases only this worker's singleton duty leases for immediate takeover. An
operator drains a fleet without a deploy. null clears a pending signal.




## OpenAPI

````yaml /api/headgate.openapi.yaml post /workers/{worker_id}/signal
openapi: 3.1.0
info:
  title: headgate control API
  version: 0.1.0
  description: >
    The web UI is one client of this control API and gets no

    privileged access — asynqmon reads Redis directly, which is why its
    compatibility

    note is three minor versions stale.


    Both the Go and Rust implementations serve this spec, and the conformance
    suite

    asserts identical responses. Every list endpoint is bounded to prevent
    inspection

    from becoming an unbounded store operation: asynq's

    GetQueueInfo is O(number of groups) and has pinned Redis CPU for seconds in

    production. Monitoring caused the outage.


    DERIVED FROM THE ARCHITECTURE, NOT FROM A PREDECESSOR'S UI. The first draft
    of this

    spec was the asynq Inspector surface -- list by state, act on one job, pause
    a queue

    -- with new nouns bolted on. That inherited three problems: it omitted bulk

    operations, history, and enqueue (which asynq and apalis-board respectively
    DO have),

    and more importantly it had no endpoint for the question this system's own
    design

    creates. When dequeue is an admission decision, the operator's first
    question is not

    "what is in the queue" but "why is THIS job not running" -- see
    /jobs/{id}/admission.

    No predecessor needs that endpoint because no predecessor has a gate.
servers:
  - url: /api/v1
security: []
paths:
  /workers/{worker_id}/signal:
    post:
      summary: Send control to a worker on its next heartbeat.
      description: >
        Faktory's BEAT carries quiet/terminate; here it is one column on the
        worker row,

        read back by the heartbeat upsert. The list endpoint separates the
        pending

        command from the worker-acknowledged status. `quiet` pauses admission
        (in-flight work

        finishes), `resume` resumes, `terminate` shuts the worker down
        gracefully, and

        `resign` releases only this worker's singleton duty leases for immediate
        takeover. An

        operator drains a fleet without a deploy. null clears a pending signal.
      parameters:
        - name: worker_id
          in: path
          required: true
          schema:
            type: string
        - $ref: '#/components/parameters/IdempotencyKey'
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              properties:
                command:
                  type:
                    - string
                    - 'null'
                  enum:
                    - quiet
                    - resume
                    - restart
                    - terminate
                    - resign
                    - null
      responses:
        '204':
          description: Signal set
        '404':
          description: No such worker
components:
  parameters:
    IdempotencyKey:
      name: Idempotency-Key
      in: header
      required: true
      schema:
        type: string
      description: >
        Required on every mutating request. A double-clicked Retry, or a proxy
        retrying a

        POST, must not enqueue the job twice. Keys are retained long enough to
        cover a

        client retry window and the response is replayed verbatim.

````