OpenClaw Sub-agents: Don't Treat a Reply as a Completion Receipt

OpenClaw's sessions_spawn is non-blocking. It returns a runId and child session when the work is accepted, not when it is complete. This means a parent orchestration session can receive partial output, summarize it, and report success while a child is still running, failed, or lost.

Wait for Completion with sessions_yield

OpenClaw documents sessions_yield as the correct way to wait for completion events. Instead of counting replies, the parent should yield and block until the child session reaches a terminal state.

Durable Workflows with Task Flow

For durable workflows, Task Flow links multi-step work to individual background-task records. This gives you a persistent record of each task's state, making reconciliation possible.

Reconcile Every Child Before Success

The author recommends reconciling every required child before allowing the parent to finish. The reconciliation should include:

• parent_run_id
• child_run_id
• terminal_state
• verification_receipt
• completion_blocker

Missing or contradictory state should produce incomplete_reconciliation, not success. A failed, cancelled, or lost child may justify a partial or blocked outcome — but only with evidence.

Test Your Orchestrator

Test your setup with three harmless children: one that succeeds, one that returns partial output then fails, and one that remains pending. The parent should refuse success until every child has an authoritative terminal state and the required verification is complete.

If your current orchestrator simply counts replies, it's time to audit it against these requirements.