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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.

agent aware

Limited machine-readable signal and partial portal coverage — documentation a human can read, but little a machine or agent can consume without scraping.

Kin Score

API Evangelist profiles Kalshi the way a machine reads it — 48 machine-readable artifacts across 1 API, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.

Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — Kalshi scores 37.6/100 (thin), with a separate agent-readiness read of 28/100 (agent aware). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.

Kin Score

This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance. Every facet and dimension name is a link: it opens that measurement's page on APIs.io, where the rating runs across the whole catalog — the exact checks that feed it, how every profiled provider distributes on it, and who is at the top of it.

Kin Score Kin Score How this is scored →
scored 2026-09-08 · rubric v0.20.0
Kalshi Kin Score — API readiness rating by API Evangelist

Put this on your own site. The badge is drawn live from Kalshi's current Kin Score — paste it once and it updates itself every time the score is recomputed. It follows your visitor's light or dark setting, and it links back here so anyone who sees it can read the full breakdown.

<!-- Kin Score · API Evangelist -->
<a href="https://providers.apievangelist.com/providers/kalshi/"
   title="Kalshi on API Evangelist — API profile and Kin Score">
  <img src="https://apis.io/badge/kalshi.svg"
       alt="Kalshi Kin Score — API readiness rating by API Evangelist" width="150" height="150" loading="lazy">
</a>

More shapes, themes and sizes → · Score as JSON · How badges work

How we profile Kalshi

Each block below is one kind of artifact we hold for Kalshi. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.

APIs 21

Each API is captured as its own OpenAPI definition — every operation, parameter, and response. This is the single most useful machine-readable description of what an API does, and it's what lets us score, lint, mock, and generate against it without asking the provider for anything.

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 within the panel for all 21 ·

Open Collections 19

Open, tool-agnostic collections carry the same runnable value as Postman without locking you to one client — the portable, forkable form of the same exercise.

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

Scroll within the panel for all 19 ·

Pricing Plans 1

Pricing is part of the interface. Machine-readable plans tell you what a tier costs and includes before you commit — one of the things the Kin Score reads for access clarity — renamed from commercial clarity in rubric 0.12, because a free statutory interface has access terms and no commercial ones.

Published pricing tiers and plan structures.

Kalshi Plans Pricing

1 plans

PLANS

Rate Limits 1

Rate limits are the difference between a demo that works and a production integration that doesn't fall over. Publishing them is an operational-transparency signal — and a hard requirement for any agent that plans its own throughput.

Documented rate limits and quota policies.

Kalshi Rate Limits

2 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals let a buyer model the financial operations of an API before it's live. We profile them for the same reason we profile pricing: the money is part of the contract.

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

Event Specifications 1

Not every API is request/response. AsyncAPI describes the event-driven and streaming side — the webhooks and channels — so the asynchronous half of the interface is documented the same way the synchronous half is.

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

Governance rulesets we run against this provider's specs — the automated checks behind parts of the score. Profiling them makes the quality bar explicit and re-runnable, not a matter of opinion.

Kalshi API Rules

7 rules · 1 errors · 6 warnings

SPECTRAL

Security Posture 2

Authentication, domain security, vulnerability disclosure, and trust-center signals — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.

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

An x-agentic-access contract marks which operations are safe for an agent to run on its own and which need a human in the loop. It is the difference between an API an agent can use and one it can use safely.

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

Every other property we hold for Kalshi — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.

Documentation 2

Reference material describing how the API behaves

Agent Surfaces 2

MCP servers, agent skills, and machine-readable catalogs

Build 1

SDKs, sample code, and the tooling you integrate with

Access & Security 2

Authentication, authorization, and security posture

Operate 1

Status, limits, changes, and where to get help

Commercial 1

Pricing, plans, and the legal terms of use

Company 2

The organization behind the API

← All providers · Data indexed from github.com/api-evangelist/kalshi · machine-readable index on apis.io

Where this information came from

This is an independent, third-party profile of Kalshi, published by API Evangelist. We do not operate, host, resell, or support these APIs, and we are not affiliated with or endorsed by the company unless stated above. Everything here is built from publicly available information — the company's own site, developer portal, documentation, public repositories, and the specifications it publishes for public use. Nothing is obtained by breaching a system, defeating an access control, or using credentials.

The Kin Score and Agent Readiness rating are independently calculated assessments of a company's public API artifacts, scored against a published rubric. They are not certifications, endorsements, security assessments, or audits.

Corrections, re-scores, and removal are free — no partnership or purchase required, and you do not need to justify the request. A removed company is recorded as unrated, never scored zero for having asked. Acknowledgement within one business day; removal within two.

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On a security or compliance team? Put security in the subject line and you will get a person, not a form — we will tell you exactly which public URLs this profile was built from.