AGUI106

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

Message: TEXT_MESSAGE_START for messageId '{messageId}', which is already open

Spec grounding

Events with the same ID (e.g., messageId, toolCallId) belong to the same logical stream

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

Example

A violating stream from the corpus (spec/fixtures/invalid/AGUI106-interleaved-same-message-id):

{"type":"RUN_STARTED","threadId":"thread_001","runId":"run_001","timestamp":1755300012500}
{"type":"TEXT_MESSAGE_START","messageId":"msg_001","role":"assistant","timestamp":1755300012600}
{"type":"TEXT_MESSAGE_START","messageId":"msg_001","role":"assistant","timestamp":1755300012700}
{"type":"TEXT_MESSAGE_END","messageId":"msg_001","timestamp":1755300012800}
{"type":"RUN_FINISHED","threadId":"thread_001","runId":"run_001","outcome":{"type":"success"},"timestamp":1755300012900}

Expected findings:

• error AGUI106 at event 2 — TEXT_MESSAGE_START for messageId 'msg_001', which is already open