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

37.6/100 thin ▬ flat Agent 28/100 agent aware Full breakdown ↓
scored 2026-09-08 · rubric v0.20.0

AccessFreeSelf serve⚡ Free to try

1 APIs

Prediction MarketsEvent ContractsExchange CFTC Trading Markets

Kin Score

Kin Score How this is scored →
scored 2026-09-08 · rubric v0.20.0

Composite quality — 37.6/100 · thin

Contract Quality 11.4 / 19

Developer Ergonomics 4.3 / 15

Access Clarity 4.3 / 15

Operational Transparency 2.6 / 10

Contract Governance 1.0 / 9

Discoverability 5.7 / 8

Regulatory Posture 4.5 / 15

Create-or-Update Ergonomics 0.0 / 10

Agent readiness — 28/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 6 / 6

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

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Regulatory Posture applies to this provider. Its tags matched the Securities & Market Data regime (on an ambiguous tag, where no other regime matched), so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

Create-or-Update Ergonomics applies to this provider. This API accepts writes, so it carries 10 points of the composite. It is scored from the published contracts themselves: whether a caller can create-or-update in one call, whether the write accepts a key the caller already holds, and whether the response says which branch ran. Without that, every write needs a search-and-branch in front of it, and the first time that check is skipped a duplicate record is created. Scored against the observed mean rather than raw — a provider at the catalog average is unchanged by this facet, not penalised by it.

The six quality facets above are damped to 75 points between them, because the conditional facet above carries the other 25. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 75% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. 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. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

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 19

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

API Collection

OPEN COLLECTION

Kalshi Trade API Manual Endpoints account API

OPEN COLLECTION

Kalshi Trade API Manual Endpoints account api-keys API

OPEN COLLECTION

Kalshi Trade API Manual Endpoints account communications API

OPEN COLLECTION

Kalshi Trade API Manual Endpoints account events API

OPEN COLLECTION

Kalshi Trade API Manual Endpoints account exchange API

OPEN COLLECTION

Kalshi Trade API Manual Endpoints account fcm API

OPEN COLLECTION

Kalshi Trade API Manual Endpoints account historical API

OPEN COLLECTION

Kalshi Trade API Manual Endpoints account incentive-programs API

OPEN COLLECTION

Kalshi Trade API Manual Endpoints account live-data API

OPEN COLLECTION

Kalshi Trade API Manual Endpoints account market API

OPEN COLLECTION

Kalshi Trade API Manual Endpoints account milestone API

OPEN COLLECTION

Kalshi Trade API Manual Endpoints account multivariate API

OPEN COLLECTION

Kalshi Trade API Manual Endpoints account order-groups API

OPEN COLLECTION

Kalshi Trade API Manual Endpoints account orders API

OPEN COLLECTION

Kalshi Trade API Manual Endpoints account portfolio API

OPEN COLLECTION

Kalshi Trade API Manual Endpoints account search API

OPEN COLLECTION

Kalshi Trade API Manual Endpoints account structured-targets API

OPEN COLLECTION

Kalshi Trade API Manual Endpoints

OPEN COLLECTION

Scroll for all 19

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

Source (apis.yml)

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.
deliveryModel:
  model: unknown
  open_source: false
  commercial: false
  callable_host: true
  label: Delivery model not determined — needs a product licence on record
  confidence: low
  source:
  - openapi
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: free
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  label: Free · Self-serve signup
  confidence: medium
  source:
  - plans
  - authentication
  - security
  generated: '2026-09-03'
  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: '0.23'
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
  tags_raw:
  - 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:
  - APIKeys
  tags_raw:
  - 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
  tags_raw:
  - 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:
  - Event
  tags_raw:
  - 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
  tags_raw:
  - 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
  tags_raw:
  - 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
  tags_raw:
  - 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
  tags_raw:
  - 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
  tags_raw:
  - 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
  tags_raw:
  - 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
  tags_raw:
  - 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
  tags_raw:
  - 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:
  - Order
  tags_raw:
  - 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
  tags_raw:
  - 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
  tags_raw:
  - 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

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