Polymarket Agents vs Sonist

What Sonist does

Mention-market trading software that listens to a live broadcast and buys the contract the moment a tracked word is said. Sonist pulls the mention markets from Kalshi and Polymarket onto one board — 53 approved events the day we checked it, 36 on Kalshi and 17 on Polymarket — each contract already carrying its keywords, its aliases and the count that settles it. Point a session at a stream URL, your microphone or your device audio and Sonist transcribes word by word; when a keyword clears its threshold it fires an immediate-or-cancel order on your own exchange account, under a contract cap and a maximum price in cents that you set before the session starts. The board re-marks over a websocket as the book moves, every detection and every skipped signal is logged with its reason, and one control flattens the position. Pro adds local speaker diarization, so a mention only counts when the voice that matters says it — the Fed governor rather than the anchor quoting him.

• Both exchanges on one board, each contract showing its keywords, aliases and minimum mention count
• Word-by-word live transcription from a stream URL, browser microphone or device audio
• Immediate-or-cancel orders on your own Kalshi account or Polymarket wallet — Sonist holds no funds
• Per-session limits: maximum contracts and a price ceiling in cents, plus a control that sells everything at once
• Speaker diarization on Pro — gate a detection to one voice on a multi-speaker broadcast

• The trade is a race, not a forecast. The market prices how likely a word is to be said; Sonist tries to buy YES in the gap between the word leaving the speaker's mouth and the book repricing. Its landing puts that at 238ms word-to-order — the vendor's own figure, measured by nobody else.
• The gap is only worth crossing if the fill is cheap. On a contract already quoted at 95¢ the gross edge is 5¢ before exchange fees, so the price ceiling — not the keyword list — is the setting that decides whether a session makes money, and it is the one thing you set yourself.
• The landing calls a qualifying fill below $1 “guaranteed profit”. It is not: the exchange settles on its own official transcript and its own rules, not on your audio feed, so a misheard word, a form that does not count, or a miscount on a contract needing 3+ or 10+ mentions is a total loss on that fill. Sonist's own risk page says as much — speech recognition, diarization and keyword detection can all be wrong, orders can go unfilled — which makes it the more honest of the two pages.