Kalshi website screenshot

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 19 APIs on the APIs.io network, including WebSocket Streaming API, AsyncAPI Specification, account API, and 16 more. Tagged areas include Prediction Markets, Event Contracts, Exchange, CFTC, and Trading.

The Kalshi catalog on APIs.io includes 1 event-driven AsyncAPI specification and 1 Spectral governance ruleset.

Kalshi’s developer surface includes authentication, documentation, API reference, GitHub presence, and 7 more developer resources.

🌐 Visit website 📡 Source on GitHub
41.1/100 thin ▬ flat Agent 43/100 agent ready Full breakdown ↓
scored 2026-07-28 · rubric v0.6
AccessFreeSelf serve⚡ Free to try
21 APIs
Prediction MarketsEvent ContractsExchangeCFTCTradingMarkets

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-07-28 · rubric v0.6
Composite quality — 41.1/100 · thin
Contract Quality 16.2 / 25
Developer Ergonomics 5.2 / 20
Commercial Clarity 5.8 / 20
Operational Transparency 3.4 / 13
Governance 5.0 / 12
Discoverability 7.4 / 10
Agent readiness — 43/100 · agent ready
Machine-Readable Contract 18 / 18
Agentic Access Contract 10 / 10
MCP Server 0 / 12
Machine-Readable Auth 10 / 10
Idempotency 0 / 9
Stable Error Semantics 8 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 7 / 7
Typed Event Surface 6 / 6
Agent Skills 0 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 0 / 3
A2A Agent Card 0 / 8
Dry-Run / Simulate Mode 0 / 4
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/kalshi: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 21

Individual APIs this provider publishes, each with its own machine-readable definition.

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 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...

Kalshi account API

The account API from Kalshi — 2 operation(s) for account.

Kalshi api-keys API

API key management endpoints

Kalshi communications API

Request-for-quote (RFQ) endpoints

Kalshi events API

Event endpoints

Kalshi exchange API

Exchange status and information endpoints

Kalshi fcm API

FCM member specific endpoints

Kalshi historical API

The historical API from Kalshi — 7 operation(s) for historical.

Kalshi incentive-programs API

Incentive program endpoints

Kalshi live-data API

Live data endpoints

Kalshi market API

The market API from Kalshi — 9 operation(s) for market.

Kalshi milestone API

Milestone endpoints

Kalshi multivariate API

Multivariate event collection endpoints

Kalshi order-groups API

Order group management endpoints

Kalshi orders API

Order management endpoints

Kalshi portfolio API

Portfolio and balance information endpoints

Kalshi search API

Search and filtering endpoints

Kalshi structured-targets API

Structured targets endpoints

Scroll for all 21

Open Collections 1

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

Kalshi Trade API Manual Endpoints

OPEN COLLECTION

Pricing Plans 1

Published pricing tiers and plan structures.

Kalshi Plans Pricing

1 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Kalshi Rate Limits

2 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

Kalshi Finops

FINOPS

Event Specifications 1

AsyncAPI definitions for this provider's event-driven and streaming APIs.

Kalshi WebSocket Streaming API

Real-time WebSocket streaming feed for the Kalshi CFTC-regulated event contracts exchange. Publishes orderbook updates, public trades, market tickers, user orders, user fills, m...

ASYNCAPI

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

Kalshi API Rules

7 rules · 1 errors 6 warnings

SPECTRAL

Security Posture 2

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Kalshi Authentication

apiKey · 3 schemes

SECURITY

Kalshi Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

Kalshi Agentic Access

98 operations · 31 acting · 1 human-in-the-loop

98 operations · 31 acting

AGENTIC

Resources

Documentation 2

Reference material describing how the API behaves

Documentation
Documentation
 APIReference
APIReference

Agent Surfaces 2

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess
AgenticAccess
 LlmsText
LlmsText

Build 1

SDKs, sample code, and the tooling you integrate with

GitHub
GitHub

Access & Security 2

Authentication, authorization, and security posture

DomainSecurity
DomainSecurity
 Authentication
Authentication

Operate 1

Status, limits, changes, and where to get help

Help
Help

Commercial 1

Pricing, plans, and the legal terms of use

Developer Agreement
Developer Agreement

Company 2

The organization behind the API

Website
Website
 LinkedIn
LinkedIn

Source (apis.yml)

apis.yml Raw ↑ 
aid: kalshi
url: https://raw.githubusercontent.com/api-evangelist/kalshi/refs/heads/main/apis.yml
name: Kalshi
kind: company
description: 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.
accessModel:
  pricing: free
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  label: Free · Self-serve signup
  confidence: high
  source:
  - plans
  - authentication
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/kalshi.png
tags:
- Prediction Markets
- Event Contracts
- Exchange
- CFTC
- Trading
- Markets
created: '2026-05-23'
modified: '2026-05-29'
specificationVersion: '0.19'
apis:
- aid: kalshi:trade-api-demo
  name: Kalshi Trade API (Demo)
  description: Demo / sandbox environment for the Kalshi Trade API - mirrors production semantics with simulated balances
    and markets for safe development and automated testing.
  humanURL: https://docs.kalshi.com/api-reference
  baseURL: https://demo-api.kalshi.co/trade-api/v2
  tags:
  - REST
  - Demo
  - Sandbox
  - Testing
  properties:
  - type: Documentation
    url: https://docs.kalshi.com/api-reference
- aid: kalshi:websocket
  name: Kalshi WebSocket Streaming API
  description: 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.
  humanURL: https://docs.kalshi.com/api-reference
  baseURL: wss://api.elections.kalshi.com/trade-api/ws/v2
  tags:
  - WebSocket
  - Streaming
  - Market Data
  properties:
  - type: Documentation
    url: https://docs.kalshi.com/api-reference
  - type: AsyncAPI
    url: https://docs.kalshi.com/asyncapi.yaml
  - type: AsyncAPI
    url: https://raw.githubusercontent.com/api-evangelist/kalshi/refs/heads/main/asyncapi/kalshi-asyncapi.yml
- aid: kalshi:asyncapi
  name: Kalshi AsyncAPI Specification
  description: Machine-readable AsyncAPI description of the Kalshi WebSocket streaming API. Suitable for generating async
    clients and documenting message schemas.
  humanURL: https://docs.kalshi.com/
  baseURL: https://docs.kalshi.com/asyncapi.yaml
  tags:
  - AsyncAPI
  - Specification
  - WebSocket
  properties:
  - type: AsyncAPI
    url: https://docs.kalshi.com/asyncapi.yaml
- aid: kalshi:python-starter
  name: Kalshi Python Starter Kit
  description: Official Python starter / SDK published by Kalshi for connecting to the Trade REST API and WebSocket streams.
    Includes request signing, authentication helpers, and example trading flows.
  humanURL: https://github.com/Kalshi/kalshi-starter-code-python
  baseURL: https://github.com/Kalshi/kalshi-starter-code-python
  tags:
  - SDK
  - Python
  - Starter
  properties:
  - type: Repository
    url: https://github.com/Kalshi/kalshi-starter-code-python
- aid: kalshi:kalshi-account-api
  name: Kalshi account API
  description: The account API from Kalshi — 2 operation(s) for account.
  humanURL: https://docs.kalshi.com/api-reference
  baseURL: https://api.elections.kalshi.com/trade-api/v2
  tags:
  - account
  properties:
  - type: OpenAPI
    url: openapi/kalshi-account-api-openapi.yml
  - type: Documentation
    url: https://docs.kalshi.com/api-reference
- aid: kalshi:kalshi-api-keys-api
  name: Kalshi api-keys API
  description: API key management endpoints
  humanURL: https://docs.kalshi.com/api-reference
  baseURL: https://api.elections.kalshi.com/trade-api/v2
  tags:
  - api-keys
  properties:
  - type: OpenAPI
    url: openapi/kalshi-api-keys-api-openapi.yml
  - type: Documentation
    url: https://docs.kalshi.com/api-reference
- aid: kalshi:kalshi-communications-api
  name: Kalshi communications API
  description: Request-for-quote (RFQ) endpoints
  humanURL: https://docs.kalshi.com/api-reference
  baseURL: https://api.elections.kalshi.com/trade-api/v2
  tags:
  - communications
  properties:
  - type: OpenAPI
    url: openapi/kalshi-communications-api-openapi.yml
  - type: Documentation
    url: https://docs.kalshi.com/api-reference
- aid: kalshi:kalshi-events-api
  name: Kalshi events API
  description: Event endpoints
  humanURL: https://docs.kalshi.com/api-reference
  baseURL: https://api.elections.kalshi.com/trade-api/v2
  tags:
  - events
  properties:
  - type: OpenAPI
    url: openapi/kalshi-events-api-openapi.yml
  - type: Documentation
    url: https://docs.kalshi.com/api-reference
- aid: kalshi:kalshi-exchange-api
  name: Kalshi exchange API
  description: Exchange status and information endpoints
  humanURL: https://docs.kalshi.com/api-reference
  baseURL: https://api.elections.kalshi.com/trade-api/v2
  tags:
  - exchange
  properties:
  - type: OpenAPI
    url: openapi/kalshi-exchange-api-openapi.yml
  - type: Documentation
    url: https://docs.kalshi.com/api-reference
- aid: kalshi:kalshi-fcm-api
  name: Kalshi fcm API
  description: FCM member specific endpoints
  humanURL: https://docs.kalshi.com/api-reference
  baseURL: https://api.elections.kalshi.com/trade-api/v2
  tags:
  - fcm
  properties:
  - type: OpenAPI
    url: openapi/kalshi-fcm-api-openapi.yml
  - type: Documentation
    url: https://docs.kalshi.com/api-reference
- aid: kalshi:kalshi-historical-api
  name: Kalshi historical API
  description: The historical API from Kalshi — 7 operation(s) for historical.
  humanURL: https://docs.kalshi.com/api-reference
  baseURL: https://api.elections.kalshi.com/trade-api/v2
  tags:
  - historical
  properties:
  - type: OpenAPI
    url: openapi/kalshi-historical-api-openapi.yml
  - type: Documentation
    url: https://docs.kalshi.com/api-reference
- aid: kalshi:kalshi-incentive-programs-api
  name: Kalshi incentive-programs API
  description: Incentive program endpoints
  humanURL: https://docs.kalshi.com/api-reference
  baseURL: https://api.elections.kalshi.com/trade-api/v2
  tags:
  - incentive-programs
  properties:
  - type: OpenAPI
    url: openapi/kalshi-incentive-programs-api-openapi.yml
  - type: Documentation
    url: https://docs.kalshi.com/api-reference
- aid: kalshi:kalshi-live-data-api
  name: Kalshi live-data API
  description: Live data endpoints
  humanURL: https://docs.kalshi.com/api-reference
  baseURL: https://api.elections.kalshi.com/trade-api/v2
  tags:
  - live-data
  properties:
  - type: OpenAPI
    url: openapi/kalshi-live-data-api-openapi.yml
  - type: Documentation
    url: https://docs.kalshi.com/api-reference
- aid: kalshi:kalshi-market-api
  name: Kalshi market API
  description: The market API from Kalshi — 9 operation(s) for market.
  humanURL: https://docs.kalshi.com/api-reference
  baseURL: https://api.elections.kalshi.com/trade-api/v2
  tags:
  - market
  properties:
  - type: OpenAPI
    url: openapi/kalshi-market-api-openapi.yml
  - type: Documentation
    url: https://docs.kalshi.com/api-reference
- aid: kalshi:kalshi-milestone-api
  name: Kalshi milestone API
  description: Milestone endpoints
  humanURL: https://docs.kalshi.com/api-reference
  baseURL: https://api.elections.kalshi.com/trade-api/v2
  tags:
  - milestone
  properties:
  - type: OpenAPI
    url: openapi/kalshi-milestone-api-openapi.yml
  - type: Documentation
    url: https://docs.kalshi.com/api-reference
- aid: kalshi:kalshi-multivariate-api
  name: Kalshi multivariate API
  description: Multivariate event collection endpoints
  humanURL: https://docs.kalshi.com/api-reference
  baseURL: https://api.elections.kalshi.com/trade-api/v2
  tags:
  - multivariate
  properties:
  - type: OpenAPI
    url: openapi/kalshi-multivariate-api-openapi.yml
  - type: Documentation
    url: https://docs.kalshi.com/api-reference
- aid: kalshi:kalshi-order-groups-api
  name: Kalshi order-groups API
  description: Order group management endpoints
  humanURL: https://docs.kalshi.com/api-reference
  baseURL: https://api.elections.kalshi.com/trade-api/v2
  tags:
  - order-groups
  properties:
  - type: OpenAPI
    url: openapi/kalshi-order-groups-api-openapi.yml
  - type: Documentation
    url: https://docs.kalshi.com/api-reference
- aid: kalshi:kalshi-orders-api
  name: Kalshi orders API
  description: Order management endpoints
  humanURL: https://docs.kalshi.com/api-reference
  baseURL: https://api.elections.kalshi.com/trade-api/v2
  tags:
  - orders
  properties:
  - type: OpenAPI
    url: openapi/kalshi-orders-api-openapi.yml
  - type: Documentation
    url: https://docs.kalshi.com/api-reference
- aid: kalshi:kalshi-portfolio-api
  name: Kalshi portfolio API
  description: Portfolio and balance information endpoints
  humanURL: https://docs.kalshi.com/api-reference
  baseURL: https://api.elections.kalshi.com/trade-api/v2
  tags:
  - portfolio
  properties:
  - type: OpenAPI
    url: openapi/kalshi-portfolio-api-openapi.yml
  - type: Documentation
    url: https://docs.kalshi.com/api-reference
- aid: kalshi:kalshi-search-api
  name: Kalshi search API
  description: Search and filtering endpoints
  humanURL: https://docs.kalshi.com/api-reference
  baseURL: https://api.elections.kalshi.com/trade-api/v2
  tags:
  - search
  properties:
  - type: OpenAPI
    url: openapi/kalshi-search-api-openapi.yml
  - type: Documentation
    url: https://docs.kalshi.com/api-reference
- aid: kalshi:kalshi-structured-targets-api
  name: Kalshi structured-targets API
  description: Structured targets endpoints
  humanURL: https://docs.kalshi.com/api-reference
  baseURL: https://api.elections.kalshi.com/trade-api/v2
  tags:
  - structured-targets
  properties:
  - type: OpenAPI
    url: openapi/kalshi-structured-targets-api-openapi.yml
  - type: Documentation
    url: https://docs.kalshi.com/api-reference
common:
- type: AgenticAccess
  url: agentic-access/kalshi-agentic-access.yml
- type: DomainSecurity
  url: security/kalshi-domain-security.yml
- type: Authentication
  url: authentication/kalshi-authentication.yml
- type: Website
  url: https://kalshi.com/
- type: Documentation
  url: https://docs.kalshi.com/
- type: APIReference
  url: https://docs.kalshi.com/api-reference
- type: Help
  url: https://help.kalshi.com/
- type: GitHub
  url: https://github.com/Kalshi
- type: Developer Agreement
  url: https://kalshi.com/developer-agreement
- type: LinkedIn
  url: https://www.linkedin.com/company/kalshi/
- type: LlmsText
  url: https://docs.kalshi.com/llms.txt
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com