Hey Vapi team👋 I'm building an AI interview product using Vapi for real-time voice + browser MediaRecorder for local video recording. I've been debugging a timestamp drift issue between my Chrome MediaRecorder recording and Vapi's WAV artifacts. Setup: - Frontend: Chrome, MediaRecorder (WebM/VP8+Opus), chunks buffered to IndexedDB then uploaded - AI voice: Vapi SDK (

@vapi-ai/web

) - Vapi

artifactPlan.recordingEnabled

is on, so I also have Vapi's server-side WAV recordings What I found: - Vapi's WAV track is

944.980s

- My Chrome WebM file (same session) is

931.863s

— a 13.1s difference - The gap is NOT a fixed offset at the start. It grows progressively across the whole session:

00:23 → 1.7s drift
02:10 → 2.4s
07:42 → 4.3s
10:43 → 4.8s
13:05 → 8.2s  ← big jump here
13:40 → 9.7s
14:52 → 12.1s
15:42 → 13.3s

- There's an initial ~1.7s offset at the start (probably Vapi session start vs MediaRecorder start timing) My questions for the Vapi team / community: 1. Does Vapi's server-side recording use RTP/NTP timestamps? I'm assuming it's immune to browser-side clock issues — can you confirm how the WAV artifacts' timeline is established? 2. Does Vapi expose a

recordingStartedAt

server timestamp anywhere in the artifact/webhook? That would at least fix the initial offset. 3. Any recommended way to sync local video with Vapi's WAV in post-processing?m. Thanks in advance 🙏