Hey API

Hey API builds open-source OpenAPI code generators and a hosted specification registry. @hey-api/openapi-ts turns an OpenAPI document into production-grade TypeScript — SDKs, types, Zod/Valibot/TypeBox validators, TanStack Query and SWR hooks, MSW and Playwright test doubles, and Fastify/NestJS/Hono/Express server handlers — across more than twenty plugins and eight HTTP client runtimes, with a sibling Python generator emitting Pydantic models. It draws over four million npm downloads a week and is used by Vercel, PayPal, AWS, Autodesk and OpenCode. The Hey API Platform (api.heyapi.dev) adds a build-attested registry: CI uploads each OpenAPI document with its repository, branch, commit and workflow provenance, and consumers resolve it back by branch, tag, version or exact commit for reproducible client generation.

Hey API publishes 7 APIs on the APIs.io network, including Get API, Hey API, Internal API, and 4 more. Tagged areas include Code Generation, Developer Tools, OpenAPI, SDK, and TypeScript.

The Hey API catalog on APIs.io includes 1 event-driven AsyncAPI specification.

Hey API’s developer surface includes documentation, API reference, getting-started guide, signup flow, support, changelog, CLI, and 26 more developer resources.

🌐 Visit website 📡 Source on GitHub

42.8/100 developing ▬ flat Agent 33/100 agent ready Front door AI 3/6 light open core · MIT Full breakdown ↓
scored 2026-10-04 · rubric v0.23.0

AccessFreemium

1 published contract

Code Generation Developer Tools OpenAPI SDK TypeScript Python API Design Specification Registry Open Source SDK Generation

Kin Score

Kin Score How this is scored →
scored 2026-10-04 · rubric v0.23.0

Composite quality — 42.8/100 · developing

Contract Quality 8.2 / 16

Developer Ergonomics 10.1 / 13

Access Clarity 2.1 / 13

Operational Transparency 3.6 / 8

Contract Governance 0.4 / 8

Discoverability 4.2 / 7

Regulatory Posture 2.5 / 15

Open Source Surface 4.0 / 10

Create-or-Update Ergonomics 0.0 / 10

Agent readiness — 33/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 7 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 6 / 6

Agent Skills 5 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 3 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 4 / 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 Horizontal (data, software, accessibility, platform) regime, 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.

Open Source Surface applies to this provider. This product is open source and we read its repository directly, so Open Source Surface carries 10 points of the composite. It is scored from what the repository actually publishes — a security policy, a contribution guide, a release history, a code of conduct — read live from the provider rather than inferred from our own catalog pointers. This facet adds; nothing was taken away to make room for it. An open-source project is not excused from the commercial facets, because exemption would strip it of the points it does earn. If we have the wrong repository, or this product is not open source, say so on your provider repo and we will drop the facet rather than have you publish against 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 65 points between them, because both conditional facets apply and carry 35 points together. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 65% 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/hey-api: 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 →

Hey API is an area vendor: providers adopt it to run part of their developer surface. This is the Kin Score checks its features can move for a provider that adopts it, what each one really earns, and what it earns nothing for.

sdk generationcapability map3 features checked 2026-09-25 · rubric v0.22.0

Hey API generates a TypeScript SDK, types, runtime validators and framework hooks from an OpenAPI. It is free, open source and self-run. On the Kin Score it can move only sdk_count_1, and only when the provider publishes the generated client as a package and declares it. One language cannot reach sdk_count_3 (Python is listed as coming soon). Zod and Valibot schemas are not JSON Schema, and the tool leaves the contract as it found it. Nothing identifies Hey API output on a provider’s surface.

Developer Ergonomics3.0 of 42 pts

Check	Earns	Through
At least one SDKconditional Developer ErgonomicsOnly when the provider publishes the generated client as a package it maintains. Hey API is mostly run by API consumers inside their own apps, and that never counts.	3.0 of 3	Typed TypeScript SDK and types

Across 8977 providers that publish a contract, adopting Hey API would move 0. Median lift: composite +0.0 (90th percentile +0.0), agent readiness +0.0 (+0.0). Conditional rows excluded.

What Hey API ships that earns nothing (3)

Zod and Valibot schemas — Zod and Valibot schemas are TypeScript code, not published JSON Schema.
Typed TypeScript SDK and types — One language (TypeScript) cannot make three SDKs. Python is listed as coming soon.
TanStack Query and 20+ plugins — Generated hooks are client code, not an example corpus.

A model, not a score. Adopting this vendor changes a provider's Kin Score only when the provider publishes the resulting artifacts on its own surface; nothing here writes a score, and no sponsorship or partnership can. The rating is not for sale → · Full vendor facets artifact

APIs 7

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

Hey API Openapi-Ts

@hey-api/openapi-ts is an OpenAPI to TypeScript code generator that emits production-grade SDKs, types, validators, query hooks, mocks and web framework handlers from any OpenAP...

Hey API Get API

The Get API from Hey API — 1 operation(s) for get.

Hey API Hey API

The Hey API API from Hey API — 1 operation(s) for hey api.

Hey API Internal API

The Internal API from Hey API — 3 operation(s) for internal.

Hey API Organizations API

The Organizations API from Hey API — 13 operation(s) for organizations.

Hey API Specifications API

The Specifications API from Hey API — 1 operation(s) for specifications.

Hey API Users API

The Users API from Hey API — 6 operation(s) for users.

Scroll for all 7

Open Collections 7

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

API Collection

OPEN COLLECTION

Hey Get API

OPEN COLLECTION

Hey Hey API API

OPEN COLLECTION

Hey Internal API

OPEN COLLECTION

Hey Organizations API

OPEN COLLECTION

Hey Specifications API

OPEN COLLECTION

Hey Users API

OPEN COLLECTION

Scroll for all 7

Pricing Plans 1

Published pricing tiers and plan structures.

Hey Api Plans Pricing

3 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Hey Api Rate Limits

5 limits

RATE LIMITS

FinOps 1

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

Hey Api Finops

FINOPS

Event Specifications 1

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

Hey Api Platform Webhooks

ASYNCAPI

Security Posture 2

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

Hey Api Authentication

http · 2 schemes

SECURITY

Hey Api Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Agentic Access 1

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

Hey Api Agentic Access

38 operations · 23 acting

AGENTIC

Resources

Get Started 4

Portal, sign-up, and the first successful call

DeveloperPortal

GettingStarted

SignUp

Sandbox

Documentation 2

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 3

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

LLMsTxt

LLMsTxt

AgentSkill

AgentSkill

Design & Contract 6

Pagination, idempotency, versioning, errors, and events

Lifecycle

Conventions

ErrorCatalog

DataModel

Webhooks

Conformance

Build 5

SDKs, sample code, and the tooling you integrate with

CodeOfConduct

CodeOfConduct

GitHubOrganization

Packages

SDKs

CLI

Access & Security 2

Authentication, authorization, and security posture

Authentication

Authentication

DomainSecurity

DomainSecurity

Operate 5

Status, limits, changes, and where to get help

IssueTracker

Releases

Support

ChangeLog

Deprecation

Commercial 1

Pricing, plans, and the legal terms of use

License

License

Company 2

The organization behind the API

Website

Website

LinkedIn

Other 3

Properties that don't map to a standard resource type

VendorFacets

VendorFacets

Overlay

Overlay

ContentSignal

ContentSignal

Source (apis.yml)

aid: hey-api
name: Hey API
description: 'Hey API builds open-source OpenAPI code generators and a hosted specification registry. @hey-api/openapi-ts
  turns an OpenAPI document into production-grade TypeScript — SDKs, types, Zod/Valibot/TypeBox validators, TanStack Query
  and SWR hooks, MSW and Playwright test doubles, and Fastify/NestJS/Hono/Express server handlers — across more than twenty
  plugins and eight HTTP client runtimes, with a sibling Python generator emitting Pydantic models. It draws over four million
  npm downloads a week and is used by Vercel, PayPal, AWS, Autodesk and OpenCode. The Hey API Platform (api.heyapi.dev) adds
  a build-attested registry: CI uploads each OpenAPI document with its repository, branch, commit and workflow provenance,
  and consumers resolve it back by branch, tag, version or exact commit for reproducible client generation.'
type: Index
deliveryModel:
  model: open-core
  license: MIT
  open_source: true
  commercial: true
  callable_host: true
  label: Open core · an OSS project plus a commercial hosted product
  confidence: high
  source:
  - license
  - openapi
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: freemium
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Freemium
  confidence: medium
  source:
  - plans
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/hey-api.png
tags:
- Code Generation
- Developer Tools
- OpenAPI
- SDK
- TypeScript
- Python
- API Design
- Specification
- Registry
- Open Source
- SDK Generation
tags_raw:
- Code Generation
- Developer Tools
- OpenAPI
- SDKs
- TypeScript
- Python
- API Design
- Specifications
- Registry
- Open Source
- Open-Source
- SDK Generation
url: https://raw.githubusercontent.com/api-evangelist/hey-api/refs/heads/main/apis.yml
created: '2025-05-02'
modified: '2026-09-16'
specificationVersion: '0.23'
apis:
- aid: hey-api:hey-api
  name: Hey API Openapi-Ts
  description: '@hey-api/openapi-ts is an OpenAPI to TypeScript code generator that emits production-grade SDKs, types, validators,
    query hooks, mocks and web framework handlers from any OpenAPI 2.0, 3.0 or 3.1 document. MIT licensed, over four million
    npm downloads a week, with a companion Python generator producing typed SDKs and Pydantic models. Consumed as a CLI, a
    Node API, a Vite plugin or a Nuxt module.'
  humanURL: https://heyapi.dev/docs/openapi/typescript/get-started
  tags:
  - Code Generation
  - OpenAPI
  - TypeScript
  - Python
  - SDK
  tags_raw:
  - Code Generation
  - OpenAPI
  - TypeScript
  - Python
  - SDKs
  properties:
  - type: Documentation
    url: https://heyapi.dev/openapi-ts/get-started
  - type: GettingStarted
    url: https://heyapi.dev/openapi-ts/get-started
  - type: CLI
    url: cli/hey-api-cli.yml
  - type: SDKs
    url: packages/hey-api-packages.yml
  - type: SourceCode
    url: https://github.com/hey-api/hey-api
- aid: hey-api:hey-api-get-api
  name: Hey API Get API
  description: The Get API from Hey API — 1 operation(s) for get.
  humanURL: https://heyapi.dev/docs/openapi/typescript/integrations
  baseURL: https://api.heyapi.dev
  tags: []
  tags_raw:
  - Get
  properties:
  - type: OpenAPI
    url: openapi/hey-api-get-api-openapi.yml
  - type: Documentation
    url: https://heyapi.dev/docs/openapi/typescript/integrations
  - type: APIReference
    url: https://heyapi.dev/docs/openapi/typescript/integrations
  - type: Authentication
    url: authentication/hey-api-authentication.yml
  - type: Conventions
    url: conventions/hey-api-conventions.yml
  - type: ErrorCatalog
    url: errors/hey-api-problem-types.yml
  - type: DataModel
    url: data-model/hey-api-data-model.yml
  - type: Webhooks
    url: asyncapi/hey-api-platform-webhooks.yml
  - type: Sandbox
    url: sandbox/hey-api-sandbox.yml
- aid: hey-api:hey-api-hey-api-api
  name: Hey API Hey API
  description: The Hey API API from Hey API — 1 operation(s) for hey api.
  humanURL: https://heyapi.dev/docs/openapi/typescript/integrations
  baseURL: https://api.heyapi.dev
  tags:
  - Hey API
  properties:
  - type: OpenAPI
    url: openapi/hey-api-hey-api-api-openapi.yml
  - type: Documentation
    url: https://heyapi.dev/docs/openapi/typescript/integrations
  - type: APIReference
    url: https://heyapi.dev/docs/openapi/typescript/integrations
  - type: Authentication
    url: authentication/hey-api-authentication.yml
  - type: Conventions
    url: conventions/hey-api-conventions.yml
  - type: ErrorCatalog
    url: errors/hey-api-problem-types.yml
  - type: DataModel
    url: data-model/hey-api-data-model.yml
  - type: Webhooks
    url: asyncapi/hey-api-platform-webhooks.yml
  - type: Sandbox
    url: sandbox/hey-api-sandbox.yml
- aid: hey-api:hey-api-internal-api
  name: Hey API Internal API
  description: The Internal API from Hey API — 3 operation(s) for internal.
  humanURL: https://heyapi.dev/docs/openapi/typescript/integrations
  baseURL: https://api.heyapi.dev
  tags:
  - Internal
  properties:
  - type: OpenAPI
    url: openapi/hey-api-internal-api-openapi.yml
  - type: Documentation
    url: https://heyapi.dev/docs/openapi/typescript/integrations
  - type: APIReference
    url: https://heyapi.dev/docs/openapi/typescript/integrations
  - type: Authentication
    url: authentication/hey-api-authentication.yml
  - type: Conventions
    url: conventions/hey-api-conventions.yml
  - type: ErrorCatalog
    url: errors/hey-api-problem-types.yml
  - type: DataModel
    url: data-model/hey-api-data-model.yml
  - type: Webhooks
    url: asyncapi/hey-api-platform-webhooks.yml
  - type: Sandbox
    url: sandbox/hey-api-sandbox.yml
- aid: hey-api:hey-api-organizations-api
  name: Hey API Organizations API
  description: The Organizations API from Hey API — 13 operation(s) for organizations.
  humanURL: https://heyapi.dev/docs/openapi/typescript/integrations
  baseURL: https://api.heyapi.dev
  tags:
  - Organization
  tags_raw:
  - Organizations
  properties:
  - type: OpenAPI
    url: openapi/hey-api-organizations-api-openapi.yml
  - type: Documentation
    url: https://heyapi.dev/docs/openapi/typescript/integrations
  - type: APIReference
    url: https://heyapi.dev/docs/openapi/typescript/integrations
  - type: Authentication
    url: authentication/hey-api-authentication.yml
  - type: Conventions
    url: conventions/hey-api-conventions.yml
  - type: ErrorCatalog
    url: errors/hey-api-problem-types.yml
  - type: DataModel
    url: data-model/hey-api-data-model.yml
  - type: Webhooks
    url: asyncapi/hey-api-platform-webhooks.yml
  - type: Sandbox
    url: sandbox/hey-api-sandbox.yml
- aid: hey-api:hey-api-specifications-api
  name: Hey API Specifications API
  description: The Specifications API from Hey API — 1 operation(s) for specifications.
  humanURL: https://heyapi.dev/docs/openapi/typescript/integrations
  baseURL: https://api.heyapi.dev
  tags:
  - Specification
  tags_raw:
  - Specifications
  properties:
  - type: OpenAPI
    url: openapi/hey-api-specifications-api-openapi.yml
  - type: Documentation
    url: https://heyapi.dev/docs/openapi/typescript/integrations
  - type: APIReference
    url: https://heyapi.dev/docs/openapi/typescript/integrations
  - type: Authentication
    url: authentication/hey-api-authentication.yml
  - type: Conventions
    url: conventions/hey-api-conventions.yml
  - type: ErrorCatalog
    url: errors/hey-api-problem-types.yml
  - type: DataModel
    url: data-model/hey-api-data-model.yml
  - type: Webhooks
    url: asyncapi/hey-api-platform-webhooks.yml
  - type: Sandbox
    url: sandbox/hey-api-sandbox.yml
- aid: hey-api:hey-api-users-api
  name: Hey API Users API
  description: The Users API from Hey API — 6 operation(s) for users.
  humanURL: https://heyapi.dev/docs/openapi/typescript/integrations
  baseURL: https://api.heyapi.dev
  tags:
  - User
  tags_raw:
  - Users
  properties:
  - type: OpenAPI
    url: openapi/hey-api-users-api-openapi.yml
  - type: Documentation
    url: https://heyapi.dev/docs/openapi/typescript/integrations
  - type: APIReference
    url: https://heyapi.dev/docs/openapi/typescript/integrations
  - type: Authentication
    url: authentication/hey-api-authentication.yml
  - type: Conventions
    url: conventions/hey-api-conventions.yml
  - type: ErrorCatalog
    url: errors/hey-api-problem-types.yml
  - type: DataModel
    url: data-model/hey-api-data-model.yml
  - type: Webhooks
    url: asyncapi/hey-api-platform-webhooks.yml
  - type: Sandbox
    url: sandbox/hey-api-sandbox.yml
common:
- type: VendorFacets
  url: vendor-facets/hey-api-vendor-facets.yml
- type: Overlay
  url: overlays/hey-api-platform-overlay.yaml
- type: IssueTracker
  url: https://github.com/hey-api/hey-api/issues
- type: Releases
  url: https://github.com/hey-api/hey-api/releases
- type: CodeOfConduct
  url: https://github.com/hey-api/hey-api/blob/main/CODE_OF_CONDUCT.md
- type: License
  name: MIT
  url: https://github.com/hey-api/hey-api/blob/main/LICENSE
- type: AgenticAccess
  url: agentic-access/hey-api-agentic-access.yml
- type: Website
  url: https://heyapi.dev/
- type: DeveloperPortal
  url: https://heyapi.dev/docs
- type: Documentation
  url: https://heyapi.dev/openapi-ts/get-started
- type: APIReference
  url: https://heyapi.dev/docs/openapi/typescript/integrations
- type: GettingStarted
  url: https://heyapi.dev/docs/openapi/typescript/get-started
- type: SignUp
  url: https://app.heyapi.dev
- type: Support
  url: https://github.com/orgs/hey-api/discussions
- type: GitHubOrganization
  url: https://github.com/hey-api
- type: LinkedIn
  url: https://www.linkedin.com/company/heyapi
- type: ChangeLog
  url: changelog/hey-api-changelog.yml
- type: Deprecation
  url: https://heyapi.dev/docs/openapi/typescript/migrating
- type: Lifecycle
  url: lifecycle/hey-api-lifecycle.yml
- type: Packages
  url: packages/hey-api-packages.yml
- type: SDKs
  url: packages/hey-api-packages.yml
- type: CLI
  url: cli/hey-api-cli.yml
- type: Sandbox
  url: sandbox/hey-api-sandbox.yml
- type: Authentication
  url: authentication/hey-api-authentication.yml
- type: Conventions
  url: conventions/hey-api-conventions.yml
- type: ErrorCatalog
  url: errors/hey-api-problem-types.yml
- type: DataModel
  url: data-model/hey-api-data-model.yml
- type: Webhooks
  url: asyncapi/hey-api-platform-webhooks.yml
- type: Conformance
  url: conformance/hey-api-conformance.yml
- type: DomainSecurity
  url: security/hey-api-domain-security.yml
- type: LLMsTxt
  url: llms/hey-api-llms.txt
- type: ContentSignal
  url: well-known/hey-api-robots.txt
- type: AgentSkill
  url: skills/_index.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
x-enrichment:
  date: '2026-08-06'
  status: enriched
  artifacts_added: 21
  pass: local-v1

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get_provider_operationsEvery operation across all of their OpenAPIs — one call instead of parsing every spec.
get_provider_toolsEvery MCP tool they ship, with the operation each wraps.
get_provider_evidenceHow each part of their score was established. Free — the basis for a claim should not sit behind it.
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apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
resolveTurn a domain, URL or GitHub org into the provider it belongs to.
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Hey API

What adopting Hey API moves on the Kin Score 1

APIs 7

Open Collections 7

Pricing Plans 1

Rate Limits 1

FinOps 1

Event Specifications 1

Security Posture 2

Agentic Access 1

Get Started 4

Documentation 2

Agent Surfaces 3

Design & Contract 6

Build 5

Access & Security 2

Operate 5

Commercial 1

Company 2

Other 3

Source (apis.yml)

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