runner.scale-check-group

Reconcile active executions for a runner group, then launch enough runners to satisfy max(min_count, demand) up to max_count. min_count is the warm-pool floor — runners kept registered with GitHub so incoming jobs claim them instantly instead of paying the cold-start cost. Called on webhook arrival, on execution-stop completion (queue-drain chain), and from periodic sweeps. Self-healing via execution-claim-watch timeout.

Demand-driven scaling primitive: reconcile + launch up to max_count.

Overview

Property	Value
Workflow type	Atomic
Library	App-runners
Version	1.0

Input Schema

Field	Type	Required	Default	Description
runner_group_uuid	uuid	Yes	—	UUID of the RunnerGroup to scale-check, picked from the organization's list of runner groups.
actor_uuid	uuid	No	—	UUID of the user or service actor who triggered this scale-check, injected server-side from the authenticated request when available; used for audit/attribution only. Omitted for system-triggered calls (webhook, periodic sweep) with no human actor.
batch_limit	integer	No	—	Cap on number of runners to launch this call. Defaults to (max_count - active) — the full headroom.

Output Schema

Field	Type	Required	Default	Description
runner_group_uuid	uuid	No	—	UUID of the RunnerGroup this action operates on, picked from the organization's list of runner groups; echoed on output alongside terminal/error payloads.
organization_uuid	uuid	No	—	UUID of the caller's organization, injected server-side from the authenticated request; scopes the operation to the correct tenant. Echoed on output alongside terminal/error payloads.
runner_execution_uuid	uuid	No	—	UUID of the RunnerExecution this action operates on, picked from the organization's (optionally group-scoped) list of executions; echoed on output alongside terminal/error payloads.
workflow_uuid	string	No	—	Engine workflow-run identifier (or, for GitHub-Actions-triggered flows, an external GitHub Actions run id) associated with this record; not a platform entity foreign key despite the name. No source is attached since there is no list/query workflow for an internal run id.
status	string	No	—	—
outcome	string	No	—	—
initiated_at	string	No	—	—
completed_at	string	No	—	—
failed_at	string	No	—	—
failure_reason	string	No	—	—
error	string	No	—	—
error_type	string	No	—	—
actor_uuid	uuid	No	—	UUID of the user or service actor who triggered this action, injected server-side from the authenticated request when available; used for audit/attribution only. Optional — omitted for system or service-triggered actions with no human actor.
reason	string	No	—	—
workflow_run_uuid	string	No	—	Engine-stamped correlation/run id for this DAG execution (ADR-015/E1 plumbing), written into state_data by action_start; not a foreign key to any business entity. No source is attached since there is no list/query workflow for an internal run id.
retry_count	integer	No	—	—
retried_from	string	No	—	—
failed_step	json	No	—	—
failed_layer	json	No	—	—
failed_at_state	json	No	—	—
compensation_trigger	json	No	—	—
comp_current_layer	json	No	—	—
comp_queue	json	No	—	—
comp_retry_count	json	No	—	—
batch_limit	integer	No	—	—
matched_runner_group_uuid	uuid	No	—	UUID of the RunnerGroup matched during this scale-check, echoed on output; picked from the organization's runner groups.
reconciled_executions	integer	No	—	—
active_execution_count	integer	No	—	—
ready_to_serve	integer	No	—	—
instance_counts	dict	No	—	—
warm_pool_enabled	boolean	No	—	—
max_count	integer	No	—	—
min_count	integer	No	—	—
floor_deficit	integer	No	—	—
launched_count	integer	No	—	—
launched_workflow_uuid	string	No	—	Engine run id of the first runner.execution-launch-* workflow started by this scale-check pass, when one was launched. Internal engine correlation id, not a business entity reference.
launched_workflow_uuids	list	No	—	—
launched_workflow_type	string	No	—	—
launch_errors	list	No	—	—
scale_action	string	No	—	—

States

State	Initial	Terminal	Success	Auto-advance	Description
pending	Yes	No	—	check	—
completed	No	Yes	Yes	—	—
failed	No	Yes	No	—	—

State Diagram

Transitions

From	Action	To	Description
pending	check	completed	—
* (any state)	fail	failed	—

API Usage

POST /api/workflows/start
Content-Type: application/json

{
  "workflow_type": "runner.scale-check-group",
  "initial_data": {
    "runner_group_uuid": "value"
  }
}