Murmur

Murmur — anonymous voice threads that remember you. Callers phone in and speak. Their number is HMAC'd with a server-side salt and discarded; their voice is replaced before storage — ElevenLabs speech-to-speech, with a dependency-free pitch/formant shifter as fallback. Nothing identifying is kept. Yet the line still knows them. Every murmur is transcribed, embedded with Voyage AI, and folded into a per-caller interest vector via an exponential moving average. On the next call, that vector is the query for MongoDB Atlas Vector Search — so the feed is personal from call two onward, with no login, no profile, and no stored identifier. Anonymized audio lives in GridFS, so documents, vectors, and blobs all sit in Atlas. Persistent context without persistent identity.