cast-child-delegationlisted

# Diecast Child Delegation Skill Complete reference for Diecast agent delegation: parent mechanics (dispatch, polling, status checks, failure handling, async patterns) and child mechanics (reading delegation context, writing output contracts). > **Canonical specs.** This skill is the runtime encoding of two specs. If the skill and the specs ever diverge, the **specs are canonical** and this skill MUST be patched. > > - **Delegation runtime:** [`docs/specs/cast-delegation-contract.collab.md`](../../../docs/specs/cast-delegation-contract.collab.md) — file-based polling, backoff, idle timeout, heartbeat-by-mtime, atomic write, RUN_ID-scoped path validation, test hooks. > - **Output JSON shape:** [`docs/specs/cast-output-json-contract.collab.md`](../../../docs/specs/cast-output-json-contract.collab.md) — contract-v2 field-by-field schema, allowed status set, artifacts[] item shape. > **File is canonical.** The child's terminal output JSON file at `<goal_dir>/.agent-run_<RUN_ID>.output.json` is authoritative. cast-server is a read-through HTTP API — it observes the file but never writes it. This skill MUST never `import requests | httpx | urllib` from a Python implementation; bash-based curl is permitted only as a best-effort dispatch primitive. When `CAST_DISABLE_SERVER=1` is set, parents skip HTTP entirely and drive state from the file alone. --- ## PART A: Parent-Side Mechanics Invoke this skill BEFORE dispatching any child agent. Follow the patterns for your specific use