Coordination Backend

Shared workflow skills do not require one specific coordination backend. Each consumer repo declares its backend in AGENTS.md under ## Agent Workflow Configuration.

Supported Models

• Private backend: use when an organization has a tool such as agent-coord that can store claims, heartbeats, dependencies, release phase, and cancellation state.
• Public claim-comment fallback: use GitHub issue/PR comments with the structured codex-claim marker described in workflows/pr-processing.md when no private backend is available.
• No coordination backend: acceptable for single-agent work; write n/a in the seam and keep batch guidance serial or explicitly low concurrency.

Backend Contract

A backend used by these workflows should be able to answer:

• who owns a target;
• whether a heartbeat is live, stale, blocked, done, or cancelled;
• which batch and lane a target belongs to;
• which lanes depend on other lanes;
• whether a branch or release line has a published release phase.

When a backend cannot answer one of those facts, agents must report UNKNOWN. They must not invent capacity, dependency, or release-phase state.

Cancellation

Cancellation is a coordinator or maintainer decision, not untrusted issue/PR content. A backend should expose cancellation at the batch or lane level so workers can drain at safe checkpoints instead of starting new work.