AGUI605

Severity: warning · Group: Subagents · Checked in: core · Since: 0.x

Message: SUBAGENT_STARTED parentSubagentRunId '{parentSubagentRunId}' matches no subagent observed in this stream

Spec grounding

parentSubagentRunId need only name a subagent that has been started, not one still active

Source: https://docs.ag-ui.com/concepts/subagents#nesting-and-concurrency

Example

A violating stream from the corpus (spec/fixtures/invalid/AGUI605-unknown-parent-subagent-run-id):

{"type":"RUN_STARTED","threadId":"thread_001","runId":"run_001","timestamp":1755300020400}
{"type":"SUBAGENT_STARTED","subagentRunId":"sub_001","name":"researcher","parentSubagentRunId":"sub_ghost","timestamp":1755300020500}
{"type":"SUBAGENT_FINISHED","subagentRunId":"sub_001","timestamp":1755300020600}
{"type":"RUN_FINISHED","threadId":"thread_001","runId":"run_001","outcome":{"type":"success"},"timestamp":1755300020700}

Expected findings:

• warning AGUI605 at event 1 — SUBAGENT_STARTED parentSubagentRunId 'sub_ghost' matches no subagent observed in this stream