Conversation latency

Opt-in audio.cpp browser streaming records sttFirstPartialMs from the first PCM chunk to the first live delta and sttSource as streaming or batch_fallback. These fields contain no transcript text.

The web voice protocol v2 browser sends bounded client_metric frames for speech end, playback start by sequence, and barge-in. Browser durations use its own monotonic clock relative to the last voiced frame, before the VAD silence hangover. Playback start comes from the audio element's playing event; the server classifies the sequence as filler or reply. A typed web turn has no speech end, so its browser playback metric is absent.

Cicero writes transcript-free records to ~/.cicero/latency/turns.*.jsonl. The private ring keeps at most four 128 KiB segments with 256 appended records per segment. Each turn writes once after server work settles and its delivered clips are acknowledged, or after a 30-second acknowledgement window. Records include input length, bounded server mark offsets, derived durations, and interruption/parking flags. A false_interrupt flag is omitted because the web transport has no definitive empty/echo classifier result. Real remote playback and capture behavior require a browser smoke test.

cicero latency --last 100
cicero latency --last 100 --json

The table reports nearest-rank p50/p95 for each available metric, grouped by surface. speech_end→reply is the end-to-end headline. brain first token begins at brain dispatch, and TTS first audio begins at the first reply sentence. Missing values are excluded from that metric's sample count.

For a live daemon synthetic-turn bench, see bench/README.md.

Switchboard classification adds intentMs to classified web-turn records, shown as intent in cicero latency (p50/p95). This is classifier elapsed time, including timeout/error fallback. Classification completes before ordinary brain dispatch and adds its latency (about p50 330 ms on the reference local model). Adopted speculative turns retain the classifier duration as well. Exact fast paths do not incur a classifier round trip.