Resources

Changelog

What shipped, release by release.

0.2.0 · October 1, 2026

A fourth venue, Opinion (opinion): markets, events, search, order books, prices and fees read from its fee contract on BNB Chain, with no key.
Live order books, trades and last prices, and your own orders and fills, over its WebSocket with an Opinion API key.
Trading: limit, market and IOC orders signed for your Opinion Safe. Built to the venue's SDK and checked against its signing byte for byte, but not yet tested against the live venue.
synpath init creates the Opinion API key by signing with your wallet.
Cross-venue matching and the arbitrage scan include Opinion's markets.

A leg worth less than its venue's minimum order value moves to the next venue, as a leg under its minimum size does.
A venue's minimum fee per order counts in each leg's cost: a leg it makes dearer than the alternative moves.

The first public release. Synpath is open source on GitHub under the MIT license, and on PyPI.

pip install synpath

Kalshi, Polymarket and Polymarket US behind the same methods, types and Synpath IDs.
Markets, events and search; order books; trades; OHLCV; fee schedules and series.
Full history where the venue keeps it: Kalshi's archived markets, trades and candles included, and long OHLCV windows fetched in pieces automatically.
Live order books, trades, orders and fills as self-healing WebSocket streams, plus Polymarket US gRPC streams.

Place, amend and cancel orders on all three venues, with your own keys, from your own machine.
Order types the venues do not have: stops, trailing stops, icebergs, OCO, brackets, TWAP and pegs, held by your self-hosted engine. See Orders.
Smart order routing: one order across venues, filled at the best price.
A journal written before anything is sent, pre-trade risk rules, a kill switch, and paper trading.

synpath serve runs the REST and WebSocket API and the execution engine on your machine, with a typed OpenAPI document for generated clients.
synpath init writes your venue keys to a private .env; synpath doctor checks what loads.

Tick-level Kalshi order books and trades: the book at any moment, every change, every trade.
Cross-venue matching: the same market on every venue, from any Synpath ID.
Get a key with synpath login and synpath keys create; see Authentication.