A sub-agent reply is not a completion receipt: orchestrator verification checklist

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

Key details

• sessions_yield is the documented way to wait for completion events.
• Task Flow links multi-step work to individual background-task records for durable workflows.
• Reconcile every required child before allowing the parent to finish.

Reconciliation checklist

The source recommends tracking the following fields per child:

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 it yourself

Spawn three harmless children:

1. One that succeeds.
2. One that returns partial output then fails.
3. One that remains pending.

The parent should refuse success until every child has an authoritative terminal state and the required verification is complete.

The takeaway

Before you trust your orchestrator, ask: does it verify every child run, or simply count the replies it receives?