Schemathesis

Schemathesis is a property-based API testing tool that automatically generates test cases from OpenAPI and GraphQL schemas to find bugs and specification violations. It uses the Hypothesis property-based testing framework to generate diverse, edge-case-covering test inputs from schema constraints, detecting server crashes, response schema violations, validation bypasses, and stateful bugs in multi-step workflows. Used by Netflix, SAP, Red Hat, IBM, and JetBrains.

Schemathesis publishes 1 API on the APIs.io network. Tagged areas include API Testing, Contract Testing, Developer Tools, Fuzzing, and OpenAPI.

The Schemathesis catalog on APIs.io includes 1 JSON-LD context and 1 Spectral governance ruleset.

Schemathesis’ developer surface includes documentation, engineering blog, code examples, and 13 more developer resources.

🌐 Visit website 📡 Source on GitHub

33.0/100 thin ▬ flat Agent 4/100 human only self hosted · MIT Full breakdown ↓
scored 2026-09-14 · rubric v0.22.0

AccessFreemium

1 APIs

API Testing Contract Testing Developer Tools Fuzzing OpenAPIProperty-Based TestingSchemathesis

Kin Score

Kin Score How this is scored →
scored 2026-09-14 · rubric v0.22.0

Composite quality — 33.0/100 · thin

Contract Quality 5.7 / 23

Developer Ergonomics 2.1 / 18

Access Clarity 2.8 / 18

Operational Transparency 4.3 / 12

Contract Governance 2.7 / 11

Discoverability 5.3 / 9

Open Source Surface 10.0 / 10

Agent readiness — 4/100 · human only

Machine-Readable Contract 0 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 0 / 10

Idempotency 0 / 9

Stable Error Semantics 0 / 8

Request/Response Examples 7 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 0 / 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

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 could not be measured. We hold no machine-readable contract for this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero: never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and several others — scorable at all.

The six quality facets above are damped to 90 points between them, because the conditional facet above carries the other 10. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 90% 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/schemathesis: 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 1

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

Schemathesis

Schemathesis is a property-based API testing tool that automatically generates test cases from OpenAPI and GraphQL schemas to find bugs and spec violations. It detects server cr...

GraphQL 1

GraphQL schemas published by this provider.

Schemathesis GraphQL API

Schemathesis is a property-based API testing tool that automatically generates test cases from OpenAPI and GraphQL schemas to find bugs and spec violations. It detects server cr...

GRAPHQL

Pricing Plans 1

Published pricing tiers and plan structures.

Schemathesis Plans Pricing

3 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Schemathesis Rate Limits

5 limits

RATE LIMITS

FinOps 1

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

Schemathesis Finops

FINOPS

Semantic Vocabularies 1

JSON-LD contexts and semantic vocabularies used across these APIs.

Schemathesis Context

23 classes · 2 properties

JSON-LD

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

Schemathesis API Rules

5 rules · 4 warnings 1 info

SPECTRAL

JSON Schema 1

Standalone JSON Schema definitions for this provider's data models.

Schemathesis Configuration

14 properties

JSON SCHEMA

JSON Structure 1

JSON Structure definitions describing this provider's data shapes.

Schemathesis Config Structure

0 properties

JSON STRUCTURE

Examples 1

Example request and response payloads for these APIs.

Schemathesis Cli Test Example

7 fields

EXAMPLE

Security Posture 1

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

Schemathesis Domain Security

TLSv1.3 · DMARC

SECURITY

Resources

Documentation 2

Reference material describing how the API behaves

ContributionGuide

ContributionGuide

Documentation

Documentation

Design & Contract 1

Pagination, idempotency, versioning, errors, and events

Vocabulary

Vocabulary

Build 4

SDKs, sample code, and the tooling you integrate with

CodeOfConduct

CodeOfConduct

GitHubOrganization

GitHubOrganization

PyPI Package

PyPI Package

Examples

Examples

Access & Security 2

Authentication, authorization, and security posture

SecurityPolicy

SecurityPolicy

DomainSecurity

DomainSecurity

Operate 1

Status, limits, changes, and where to get help

IssueTracker

IssueTracker

Commercial 1

Pricing, plans, and the legal terms of use

License

License

Company 3

The organization behind the API

LinkedIn

Website

Website

Blog

Blog

Other 2

Properties that don't map to a standard resource type

Docker Image

Docker Image

Research

Research

Source (apis.yml)

aid: schemathesis
name: Schemathesis
description: Schemathesis is a property-based API testing tool that automatically generates test cases from OpenAPI and GraphQL
  schemas to find bugs and specification violations. It uses the Hypothesis property-based testing framework to generate diverse,
  edge-case-covering test inputs from schema constraints, detecting server crashes, response schema violations, validation
  bypasses, and stateful bugs in multi-step workflows. Used by Netflix, SAP, Red Hat, IBM, and JetBrains.
type: Index
deliveryModel:
  model: self-hosted
  license: MIT
  open_source: true
  commercial: false
  callable_host: false
  label: Self-hosted open source · you run it yourself
  confidence: high
  source:
  - license
  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/schemathesis.png
tags:
- API Testing
- Contract Testing
- Developer Tools
- Fuzzing
- OpenAPI
- Property-Based Testing
- Schemathesis
url: https://raw.githubusercontent.com/api-evangelist/schemathesis/refs/heads/main/apis.yml
created: '2026-03-25'
modified: '2026-05-02'
specificationVersion: '0.23'
apis:
- aid: schemathesis:schemathesis
  name: Schemathesis
  description: Schemathesis is a property-based API testing tool that automatically generates test cases from OpenAPI and
    GraphQL schemas to find bugs and spec violations. It detects server crashes, schema violations, validation bypasses, and
    integration failures with minimal maintenance overhead—tests adapt automatically as schemas evolve.
  humanURL: https://schemathesis.io
  tags:
  - API Testing
  - Contract Testing
  - Fuzzing
  - GraphQL
  - Hypothesis
  - OpenAPI
  - Property-Based Testing
  - Python
  properties:
  - type: Documentation
    url: https://schemathesis.readthedocs.io
  - type: GitHubRepository
    url: https://github.com/schemathesis/schemathesis
  - type: PyPI Package
    url: https://pypi.org/project/schemathesis/
  - type: GettingStarted
    url: https://schemathesis.readthedocs.io/en/stable/getting-started.html
  - type: Docker Image
    url: https://hub.docker.com/r/schemathesis/schemathesis
  - type: GitHub Action
    url: https://github.com/schemathesis/action
  - type: ChangeLog
    url: https://github.com/schemathesis/schemathesis/releases
  - type: JSONSchema
    url: https://raw.githubusercontent.com/api-evangelist/schemathesis/refs/heads/main/json-schema/schemathesis-config-schema.json
  - type: JSONStructure
    url: https://raw.githubusercontent.com/api-evangelist/schemathesis/refs/heads/main/json-structure/schemathesis-config-structure.json
  - type: JSONLD
    url: https://raw.githubusercontent.com/api-evangelist/schemathesis/refs/heads/main/json-ld/schemathesis-context.jsonld
  - url: graphql/schemathesis-graphql.md
    type: GraphQL
common:
- type: IssueTracker
  url: https://github.com/schemathesis/schemathesis/issues
- type: SecurityPolicy
  url: https://github.com/schemathesis/schemathesis/blob/master/SECURITY.md
- type: CodeOfConduct
  url: https://github.com/schemathesis/schemathesis/blob/master/CODE_OF_CONDUCT.md
- type: ContributionGuide
  url: https://github.com/schemathesis/schemathesis/blob/master/CONTRIBUTING.md
- type: License
  name: MIT
  url: https://github.com/schemathesis/schemathesis/blob/master/LICENSE
- type: DomainSecurity
  url: security/schemathesis-domain-security.yml
- type: LinkedIn
  url: https://www.linkedin.com/company/schemathesis-io
- type: Website
  url: https://schemathesis.io
- type: Documentation
  url: https://schemathesis.readthedocs.io
- type: GitHubOrganization
  url: https://github.com/schemathesis
- type: PyPI Package
  url: https://pypi.org/project/schemathesis/
- type: Docker Image
  url: https://hub.docker.com/r/schemathesis/schemathesis
- type: Blog
  url: https://schemathesis.io/blog
- type: Research
  url: https://dl.acm.org/doi/10.1145/3510003.3510097
- type: Vocabulary
  url: https://raw.githubusercontent.com/api-evangelist/schemathesis/refs/heads/main/vocabulary/schemathesis-vocabulary.yml
- type: Examples
  url: https://raw.githubusercontent.com/api-evangelist/schemathesis/refs/heads/main/examples/schemathesis-cli-test-example.json
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

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