Connect to Polymarket, Kalshi, and Hyperliquid through a single REST API and Rust SDK. Normalized markets, cross-exchange matching, real-time data.
Free tier
Unlimited
Latency
<80ms
Uptime
99.97%
event · matched 3/3
Will Bitcoin close above $120k on May 31, 2026?
[ // 01 · coverage ]
Polymarket and Kalshi are live today. Hyperliquid's HIP-4 outcome markets are landing — read paths and signing primitives are already shipping behind a flag.
Markets
12k+
WS streams
live
Trading
ready
Markets
8k+
WS streams
live
Trading
ready
Markets
HIP-4
WS streams
wired
Trading
Q3 ’26
[ // 03 · matching ]
Find the same sports event on Polymarket and Kalshi. We compute the match score with embeddings and serve the result with a 60-second cache.
# Match sports markets across exchanges
curl https://api.papi.market/matching-markets/sports \
-H "X-API-Key: <your-api-key>"[
{
"title": "Suns vs. Lakers",
"league": "NBA",
"polymarket_slug": "nba-phx-lal-2026-04-10",
"kalshi_ticker": "KXNBAGAME-26APR10PHXLAL-PHX",
"match_score": 0.9126
},
{
"title": "Lightning vs. Bruins",
"league": "NHL",
"polymarket_slug": "nhl-tb-bos-2026-04-11",
"kalshi_ticker": "KXNHLGAME-26APR11TBBOS-TB",
"match_score": 0.9285
}
][ // 02 · what you get ]
Polymarket and Kalshi today, Hyperliquid landing soon. Every market is normalized to the same schema — same field names, same Decimal-typed prices, same outcome shape.
Wallet keys are encrypted with per-user DEKs wrapped by Vault Transit. We derive what we need (CLOB API keys, agent wallets) and never expose secret material to the wire.
WebSocket fan-out hub with Redis pub/sub for cross-pod broadcast. Subscribe once, get every orderbook tick, last trade, and ticker update from every venue.
[ // 04 · workflow ]
From sign-up to a matched cross-exchange query is four CLI lines. No SDK install required for the first call.
Create your free account and get on the waitlist.
$ open dashboard.papi.market/signupOnce approved, generate an API key from the dashboard in seconds.
papi_sk_live_•••••Search and filter across every exchange with one request.
GET /markets?status=openCompare prices for the same event on Polymarket and Kalshi, side by side.
GET /matching-markets[ // 05 · sdk ]
The Rust SDK ships first because that's what we run in production. Python and TypeScript are on deck. cURL works today for everyone else.
use papi_sdk::{PapiClient, Exchange};
#[tokio::main]
async fn main() {
let client = PapiClient::builder()
.api_key("papi_sk_your_key")
.build();
// Markets across every venue, one shape
let markets = client
.markets(Exchange::Polymarket)
.status("open")
.limit(10)
.fetch().await?;
// Stream realtime ticks across exchanges
let mut stream = client
.stream()
.orderbooks(&[markets[0].id.clone()])
.subscribe().await?;
}Strict normalization keeps the unified types lean — every field is populated by every exchange with semantically equivalent data. No fabricated zeros, no copied values.
[ // 06 · operations ]
Manage keys, monitor rate limits, configure exchange credentials, and watch your spend land — all in the dashboard.
API Calls · 24h
12,847
+8.4%Active Keys
3
Exchanges
2/3
livep50 latency
62ms
−4msapi calls · last 18h
▲ 8.4%recent · live
[ // 07 · pricing ]
We're here to ship infrastructure, not lock you behind a paywall. Paid tiers may come later for very high-volume use, but the free tier isn't going anywhere.
/ forever · no card · no limits
For individuals, hackers, and trading desks alike. Same API, same data, same SDK.
what's included
For teams that outgrow the free-tier rate limits. Higher throughput, dedicated infra, white-glove support.
[ // 08 · faq ]
05 questions · ask another
Polymarket and Kalshi today, with Hyperliquid (HIP-4 outcome markets) landing soon. Read paths and signing primitives are already wired behind a feature flag. All exchanges are accessible through the same unified API and SDK.
Yes. The free tier is here to stay. It includes unlimited API calls across every supported exchange, the Rust SDK, and real-time WebSocket streaming. Paid tiers may show up later for very high-volume use, but the free tier isn’t going anywhere.
Rust today. Python and TypeScript are on deck. You can also use the REST API directly with any language via cURL or your preferred HTTP client.
Generous limits designed to stay out of your way for everyday use. Check the docs for current numbers — they apply per API key and reset on a sliding window.
Per-user data encryption keys (DEKs) wrapped by Vault Transit, with the underlying KEK held by AWS KMS. Wallet keys never leave our infrastructure unencrypted, and we use them only to derive what we need (CLOB API keys, Hyperliquid agent wallets).
[ ready · v0.4.2 ]
Free forever. Unlimited calls. One key for Polymarket, Kalshi, and everything we ship next.