AGUI903

Severity: info · Group: Protocol hygiene · Checked in: core · Since: 0.x

Message: CUSTOM event name '{name}' has no namespace prefix (e.g. 'vendor.event')

Spec grounding

Teams should document their custom events to ensure consistent implementation across frontends and agents.

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

The spec is not fully explicit here; the ambiguity is tracked as SQ-14 and the severity is capped accordingly (false positives are worse than false negatives).

Example

A violating stream from the corpus (spec/fixtures/invalid/AGUI903-custom-name-not-namespaced):

{"type":"RUN_STARTED","threadId":"thread_001","runId":"run_001","timestamp":1755300022600}
{"type":"CUSTOM","name":"update","value":{"x":1},"timestamp":1755300022700}
{"type":"RUN_FINISHED","threadId":"thread_001","runId":"run_001","outcome":{"type":"success"},"timestamp":1755300022800}

Expected findings:

• info AGUI903 at event 1 — CUSTOM event name 'update' has no namespace prefix (e.g. 'vendor.event')