Checkmate
Checkmate is a shopping intelligence and data company whose network powers three products: Checkmate for consumers (a browser extension and mobile app that automatically finds the best price and applies working discount codes across 284,000+ merchants for 5M+ monthly shoppers), Mate for brands (AI-powered revenue intelligence), and OpenStock for publishers and agents. OpenStock is a commerce API and Model Context Protocol (MCP) server that exposes the entire Checkmate network through a single endpoint — letting AI agents, shopping copilots, and applications discover merchants, pull live catalogues and offers, generate real merchant-backed discount codes, check availability, and attribute orders. Backed by GV (Google Ventures).
Real signal across most facets with visible, nameable gaps — the contract exists but is thin, or the portal is good while governance and commercial terms are absent.
API Evangelist profiles Checkmate the way a machine reads it — 11 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 — Checkmate scores 42.4/100 (developing), with a separate agent-readiness read of 25/100 (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
How this is scored →scored 2026-09-10 · rubric v0.20.0
Put this on your own site. The badge is drawn live from Checkmate'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/checkmate/"
title="Checkmate on API Evangelist — API profile and Kin Score">
<img src="https://apis.io/badge/checkmate.svg"
alt="Checkmate Kin Score — API readiness rating by API Evangelist" width="150" height="150" loading="lazy">
</a>[](https://providers.apievangelist.com/providers/checkmate/)<!-- Kin Score · API Evangelist -->
<a href="https://providers.apievangelist.com/providers/checkmate/"
title="Checkmate on API Evangelist — API profile and Kin Score">
<img src="https://apis.io/badge/checkmate/card.svg"
alt="Checkmate Kin Score — API readiness rating by API Evangelist" width="340" height="120" loading="lazy">
</a>More shapes, themes and sizes → · Score as JSON · How badges work
How we profile Checkmate
Each block below is one kind of artifact we hold for Checkmate. 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 3
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.
Checkmate Health API
The Health API from Checkmate — 1 operation(s) for health.
Checkmate Merchants API
The Merchants API from Checkmate — 2 operation(s) for merchants.
Checkmate Shoppers API
The Shoppers API from Checkmate — 1 operation(s) for shoppers.
Open Collections 4
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).
API Collection
OPEN COLLECTIONOpenStock Health API
OPEN COLLECTIONOpenStock Health Merchants API
OPEN COLLECTIONOpenStock Health Shoppers API
OPEN COLLECTIONMCP Servers 1
Model Context Protocol servers expose these APIs directly to AI agents. We profile them because agent-native access is the fastest-growing way this provider's capabilities actually get used.
Model Context Protocol servers that expose these APIs to AI agents.
Checkmate MCP Server
OpenStock by Checkmate — "the world's largest MCP for ecommerce." A single Model Context Protocol server that exposes catalogues, offers, and merchant-backed discount-code gener...
MCP SERVERSecurity Posture 3
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.
Resources
Every other property we hold for Checkmate — 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.
Get Started 2
Portal, sign-up, and the first successful call
Documentation 2
Reference material describing how the API behaves
Agent Surfaces 4
MCP servers, agent skills, and machine-readable catalogs
Design & Contract 6
Pagination, idempotency, versioning, errors, and events
Access & Security 5
Authentication, authorization, and security posture
Operate 1
Status, limits, changes, and where to get help
Commercial 2
Pricing, plans, and the legal terms of use
Company 2
The organization behind the API
Other 1
Properties that don't map to a standard resource type
← All providers · Data indexed from github.com/api-evangelist/checkmate · machine-readable index on apis.io
This is an independent, third-party profile of Checkmate, 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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