Agent Runtime workflow results and errors

This contract defines deterministic aggregation of child capability and tool outcomes for the bounded workflow API.

Result aggregation

A workflow result contains an immutable workflow identifier, terminal status, ordered child summaries, and bounded usage metadata. Child outputs are retained only when the workflow contract explicitly requests them; payloads are never written to operational logs.

The aggregate status is deterministic:

Child outcomes	Workflow status
All completed	completed
At least one failed and no cancellation/timeout	failed
Any child cancelled by caller or policy	cancelled
Any deadline exceeded	timed_out

Cancellation and timeout take precedence over ordinary failure. Within the same class, the first terminal child outcome is preserved as the workflow’s primary reason; later outcomes remain bounded summaries.

Error propagation

Typed capability, provider, and tool errors retain their stable public code and safe message. The workflow wraps them with workflow and child correlation IDs without changing the underlying category. Unexpected exceptions normalize to a stable workflow_execution_failed error; exception text and tracebacks remain internal diagnostics.

Native caller cancellation is re-raised unchanged. A workflow never retries, substitutes, or suppresses a child error unless an explicit reviewed policy allows that behavior.

Observability

Terminal workflow events include workflow and child execution identifiers, status, primary reason code, duration, and bounded child counts. They exclude prompts, tool arguments or outputs, credentials, provider payloads, and raw exception text.

Audit record

WorkflowAuditRecord is the storage-neutral immutable envelope for downstream audit consumers. It contains the event, timestamp, request/execution identity, optional status and reason code, and bounded step/group counts. It deliberately has no payload fields. Persistence, retention, export, and external audit services remain deployment-owned follow-up work.

Applications may inject an asynchronous WorkflowAuditSink to receive records. The default sink discards them, and sink failures are isolated from workflow execution so observability cannot change the execution outcome. Each delivery is bounded by a finite timeout (250ms by default); a slow sink is cancelled and the record is dropped with a structured timeout warning. The runtime does not retry or provide guaranteed delivery.