AGUI001

Severity: error · Group: Lifecycle · Checked in: core · Since: 0.x

Message: First event of the run is {type}; expected RUN_STARTED

Spec grounding

The RunStarted event is the first event emitted when an agent begins processing a request.

Source: https://docs.ag-ui.com/concepts/events#runstarted

Example

A violating stream from the corpus (spec/fixtures/invalid/AGUI001-first-event-not-run-started):

{"type":"TEXT_MESSAGE_START","messageId":"msg_001","role":"assistant","timestamp":1755300007900}
{"type":"TEXT_MESSAGE_CONTENT","messageId":"msg_001","delta":"Hello without a run.","timestamp":1755300008000}
{"type":"TEXT_MESSAGE_END","messageId":"msg_001","timestamp":1755300008100}
{"type":"RUN_FINISHED","threadId":"thread_001","runId":"run_001","timestamp":1755300008200}

Expected findings:

• error AGUI001 at event 0 — First event of the run is TEXT_MESSAGE_START; expected RUN_STARTED