Kalshi
Kalshi is a CFTC-regulated US exchange for binary event contracts on real-world outcomes - elections, economics, weather, sports, and more. The platform exposes a public REST trading API and WebSocket streams for market data, orders, positions, and portfolio actions, with a published OpenAPI 3 specification and AsyncAPI definition for the streaming surface. A demo environment mirrors production for safe development. Official Python and community SDKs are provided.
Kalshi publishes 5 APIs on the APIs.io network, including Trade API (REST), Trade API (external-api host), WebSocket Streaming API, and 2 more. Tagged areas include Prediction Markets, Event Contracts, Exchange, CFTC, and Trading.
Kalshi’s developer surface includes documentation, API reference, GitHub presence, and 4 more developer resources.
APIs
Kalshi Trade API (REST)
Public REST API for trading on Kalshi - browse markets, events, and series, place and cancel orders, manage portfolio and positions, fund and withdraw, and pull historical trade...
Kalshi Trade API (external-api host)
Alternate production host for the Kalshi Trade API, used by external integrators. Same API surface and authentication as the primary host.
Kalshi Trade API (Demo)
Demo / sandbox environment for the Kalshi Trade API - mirrors production semantics with simulated balances and markets for safe development and automated testing.
Kalshi WebSocket Streaming API
Real-time streaming feed for market data, order book updates, fills, and portfolio events on Kalshi. Documented as an AsyncAPI spec alongside the OpenAPI REST surface.
Kalshi OpenAPI Specification
Machine-readable OpenAPI 3 description of the Kalshi Trade REST API. Suitable for generating clients, mocks, and contract tests.
Kalshi AsyncAPI Specification
Machine-readable AsyncAPI description of the Kalshi WebSocket streaming API. Suitable for generating async clients and documenting message schemas.
Kalshi Python Starter Kit
Official Python starter / SDK published by Kalshi for connecting to the Trade REST API and WebSocket streams. Includes request signing, authentication helpers, and example tradi...