How We Added AI Summaries and Chapters to Video Recordings

You record a 10-minute product demo. Someone on your team gets the link a week later. They want to know: what's in this video? Is this the one about the new API, or the one about the dashboard redesign? Transcripts help — you can skim the text. But skimming a wall of timestamped segments isn't much faster than watching the video. What you really want is a summary at the top and chapter markers that let you jump to the part you care about. SendRec already transcribes every video with whisper.cpp. We had the transcript sitting in the database as structured JSON segments with timestamps. All we needed was something to read that transcript and produce a summary and chapter list. Why an LLM and not heuristics The straightforward approach would be to split the transcript into chunks and use the first sentence of each chunk as a chapter title. That works for scripted content with clear section breaks. It falls apart for real recordings — people repeat themselves, go on tangents, circle back t