Synpath
NewEvery Kalshi order book, every tick.Full-depth books and trades for every past Kalshi trade. Query any moment in under a minute.Get the data →

One API for every prediction market

Trade with algorithms, connect with apps, and build financial apps with our easy-to-use SDK.

Get API KeyDocs
Open source · MIT licensed
KKalshiPPolymarketUSPolymarket USHHyperliquidsoonNNovigsoon
pip install synpath

import synpath

# Same client, same methods, every venue
kalshi = synpath.Kalshi()
poly = synpath.Polymarket()

market = kalshi.fetch_markets(limit=1)[0]
print(market.title)
print(market.yes.quote.bid, market.yes.quote.ask)   # 0.10 0.12

What you can build

Tick-level backtesting

Every Kalshi order book update, recorded.Get the data

KKXFED-26OCTsize
44¢420
43¢860
42¢1,310
spread 1¢
41¢1,200
40¢740
39¢380
14:02:11.418bid 41¢+400
14:02:11.902ask 42¢−300
14:02:12.277bid 40¢+120
14:02:12.640ask 43¢+250
14:02:13.105bid 41¢−80
replaying every book update

Smart order routing

Best price across venues, one order.

Bitcoin above $70k on Sep 30?
buy 500 YES
Kask 41¢best→ 320
320 available
Pask 42¢→ 180
600 available
all on Polymarket: 42¢+avg 41.4¢

Multi-venue trading

One order shape for every venue.

buy 100 YES @ 41¢
K✓ filled
P✓ filled
US✓ filled

Matched events

The same question, found on every venue.

Fed cuts 25 bps in October?
P38¢
K39¢
Same bet

Cross-venue arbitrage

Pairs priced below $1, after fees.

Will the Fed cut rates in October?
PBuy YES41¢
KBuy NO55¢
cost 97.6¢ with fees · pays $1+2.4¢

Products built on Synpath

Unified Market Research

Every Kalshi and Polymarket market on one event, side by side.

Open Unified Market Research
Fed decision in October?4 matched
No change
P61¢
K60¢
Cut 25 bps
P38¢
K39¢

Write once. Trade everywhere.

Code for one venue runs on all of them.

Market data
Books, quotes and trades in one shape.
Trading
Place, amend and cancel anywhere.
Matched markets
One proposition, every venue.
Streaming
Live books and fills over WebSocket.
Non-custodial
Your keys and funds stay yours.
Advanced order types
Stop, limit, trailing stop, iceberg, OCO, bracket, TWAP.

Install in seconds.

Python$ pip install synpath
TypeScript$ npx openapi-typescript https://api.synpath.dev/openapi.json
REST$ curl https://api.synpath.dev/search?q=fed