Core Concepts

Supported Exchanges

Exchanges available through Synpath, their capabilities, and upcoming integrations.

Synpath gives one API over several prediction market exchanges. The venue key is the value you pass everywhere: the prefix of every Synpath id, the argument to synpath.exchange(...), and the path segment in the REST API.

Available exchanges

Exchange	Venue key	Description	REST	WebSocket
Kalshi	`kalshi`	CFTC-regulated US exchange. One book per market, quoted on the YES leg.	Market data, trading	Order book, ticker, trades, market status, orders, fills, positions
Polymarket	`polymarket`	On-chain CLOB on Polygon. YES and NO are separate tokens; Synpath folds them into one market.	Market data, trading	Order book, ticker, trades; orders and fills on the user stream
Polymarket US	`polymarket_us`	CFTC-regulated US exchange, separate from the on-chain CLOB. A retail API and an exchange API for onboarded firms.	Market data, trading	Order book, ticker, trades; orders, fills, positions, balance on the private stream
Opinion	`opinion`	On-chain CLOB on BNB Chain, settled in USDT. YES and NO are separate tokens, as on Polymarket; a categorical topic is an event of binary markets.	Market data, trading (not yet live-tested)	Order book, last price, trades; orders and fills on the user stream. Every channel needs an Opinion API key

import synpath

kalshi = synpath.exchange("kalshi")
polymarket = synpath.exchange("polymarket")
polymarket_us = synpath.exchange("polymarket_us")
opinion = synpath.exchange("opinion")

Coming soon

Exchange	Description	Status
Novig	US regulated prediction markets	Coming soon
Hyperliquid	Prediction markets on the Hyperliquid L1	Coming soon

Differences handled for you

One price. Every price is the YES price, on every venue. Polymarket's NO token and Kalshi's reflected NO book are read back onto the YES leg.
One id. venue:native, so an id says where it lives; see Synpath IDs.
Market orders. No venue has a true market order. Synpath sends an immediate limit at your protection price and refuses one without it.
Contracts, not tokens. Amounts are contracts everywhere. On Polymarket, a position is the net of the YES and NO token inventories.
Fees. fetch_fee_schedule reads each venue's own schedule so an estimate is available before you trade. Opinion publishes its rates only on chain; Synpath reads them there, with no key or wallet.
Rate limits. Each adapter knows its venue's limits and backs off on RateLimitExceeded, honouring retry_after when the venue sends one.

Opinion's terms of use bar residents and citizens of several countries, the US and UK among them. Check them before trading there.

Polymarket and Polymarket US share a brand and nothing else. The first is the on-chain order book; the second is the regulated US exchange. They are separate venue keys with separate credentials.

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