quic.QuicSession.onqlog

The callback to invoke when qlog data is available. Requires sessionOptions.qlog to be true. The callback receives a string chunk of JSON-SEQ formatted qlog data and a boolean fin flag. When fin is true, the chunk is the final qlog output for this session and the concatenated chunks form a complete qlog trace. Read/write.

Qlog data arrives during the connection lifecycle. The first chunk contains the qlog header with format metadata. Subsequent chunks contain trace events. The final chunk (with fin set to true) is emitted during session destruction and completes the JSON-SEQ output.

Can also be set via the onqlog option in quic.connect() or quic.listen().