Antithesis

Antithesis is an autonomous software testing platform that finds deep bugs in mission-critical systems using deterministic simulation and continuous fuzzing. It runs your entire system inside a deterministic hypervisor, injects faults and network partitions, explores reachable states, and reproduces any bug perfectly for time-travel "multiverse" debugging and automated root-cause analysis. Teams integrate through language SDKs (Go, Java, C/C++, Python, JavaScript, Rust, .NET) that define always/sometimes properties and assertions, package their software with Docker Compose or Kubernetes, then launch tests through a webhook/REST API or the snouty CLI. It is used to harden databases, distributed systems, blockchains, and financial trading infrastructure.

Antithesis is listed with 1 API on the APIs.io network. Tagged areas include Company, Developer Tools, Testing, Software Testing, and Deterministic Simulation.

Antithesis’ developer surface includes documentation, API reference, getting-started guide, engineering blog, support, authentication, CLI, and 15 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

35.2/100 thin ▬ flat Agent 10/100 agent aware Front door AI 3/6 light saas Full breakdown ↓
scored 2026-10-31 · rubric v0.25.0 · Show this score on your site →

1 API

Company Developer Tools Testing Software TestingDeterministic SimulationFuzzingReliability Distributed Systems SDK

Kin Score

Kin Score How this is scored →
scored 2026-10-31 · rubric v0.25.0

Composite quality — 35.2/100 · thin

Contract Quality 0.0 / 21

Developer Ergonomics 13.4 / 17

Access Clarity 7.2 / 17

Operational Transparency 1.5 / 11

Contract Governance 0.5 / 10

Discoverability 5.6 / 9

Regulatory Posture 4.4 / 15

Agent readiness — 10/100 · agent aware

Machine-Readable Contract 0 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 0 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 0 / 7

Typed Event Surface 6 / 6

Agent Skills 5 / 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

Pagination 5 / 5

Distinct Operations 3 / 3

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.

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 85 points between them, because the conditional facet above carries the other 15. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 85% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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Agent readiness — checks not met, largest first (exact, from this profile):

Machine-Readable Contract +18 pts — api_specs includes an OpenAPI document
MCP Server +12 pts — deployment.mode + probe verdict on the mcp/ manifest, not the pointer; an unprobed slug falls back to authorship
Agentic Access Contract +10 pts — agentic_access artifact present (x-agentic-access), graded by author
Idempotency +9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented)
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
Stable Error Semantics +8 pts — OpenAPI $refs a shared error schema across 4xx/5xx responses (verified), else common[].type includes ErrorCatalog / ErrorCodes / DeclineCodes

10 more unmet checks in the Agent Readiness table above.

Kin Score — facets with the most composite points still available (weight × headroom):

Contract Quality scores 0.0 — up to +25.0 composite points
Access Clarity scores 42.1 — up to +11.6 composite points
Contract Governance scores 4.5 — up to +11.5 composite points

Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.

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 the provider profile at artifacts.apis.io/antithesis/apis.yml: open an issue on github.com/api-evangelist/antithesis to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Markets this provider is in provisional

The Kin Score Market layer reads a provider inside its market: its position, and how deep its integrations go. Depth is only comparable within a position. Provisional and unweighted: not part of the Kin Score or agent readiness.

Market	Position	Depth	Registered MCP server	Declares compatibility
Agent Skills (SKILL.md packages)	builds-on	33.4	-	1

Registered MCP server and declares compatibility are report only — not weighted. Undeclared means we found nothing we can read, so there is no number: we never infer integrations.

APIs 1

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

Antithesis Platform API (Webhooks)

Programmatic access to the Antithesis autonomous testing platform via tenant-scoped webhook endpoints. POST /basic_test launches a test run; POST /debugging starts a multiverse ...

Security Posture 2

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

Antithesis Authentication

http/openIdConnect · 4 schemes

SECURITY

Antithesis Domain Security

TLSv1.3 · HSTS · DNSSEC · DMARC

SECURITY

Resources

Get Started 3

Portal, sign-up, and the first successful call

DeveloperPortal

DeveloperPortal

GettingStarted

GettingStarted

Login

Documentation 2

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 2

MCP servers, agent skills, and machine-readable catalogs

AgentSkill

AgentSkill

LLMsTxt

LLMsTxt

Design & Contract 2

Pagination, idempotency, versioning, errors, and events

Conventions

Conventions

Conformance

Conformance

Build 4

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

Packages

SDKs

CLI

Access & Security 3

Authentication, authorization, and security posture

TrustCenter

TrustCenter

Authentication

Authentication

DomainSecurity

DomainSecurity

Operate 1

Status, limits, changes, and where to get help

Support

Support

Commercial 2

Pricing, plans, and the legal terms of use

TermsOfService

TermsOfService

PrivacyPolicy

PrivacyPolicy

Company 3

The organization behind the API

BlogRSS

BlogRSS

Website

Website

Blog

Blog

Source (apis.yml)

aid: antithesis
name: Antithesis
description: Antithesis is an autonomous software testing platform that finds deep bugs in mission-critical systems using
  deterministic simulation and continuous fuzzing. It runs your entire system inside a deterministic hypervisor, injects faults
  and network partitions, explores reachable states, and reproduces any bug perfectly for time-travel "multiverse" debugging
  and automated root-cause analysis. Teams integrate through language SDKs (Go, Java, C/C++, Python, JavaScript, Rust, .NET)
  that define always/sometimes properties and assertions, package their software with Docker Compose or Kubernetes, then launch
  tests through a webhook/REST API or the snouty CLI. It is used to harden databases, distributed systems, blockchains, and
  financial trading infrastructure.
url: https://raw.githubusercontent.com/api-evangelist/antithesis/refs/heads/main/apis.yml
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: false
  label: Hosted service · you call their endpoint
  confidence: medium
  source:
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: unknown
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Unknown
  confidence: low
  source:
  - authentication
  - security
  generated: '2026-09-03'
  method: derived
image: https://github.com/antithesishq.png
x-type: company
x-source: vc-portfolio
x-backed-by:
- amplify-partners
- spark-capital
x-tier: stub
x-tier-reason: portfolio-lead
specificationVersion: '0.23'
created: '2026-07-17'
modified: '2026-10-06'
tags:
- Company
- Developer Tools
- Testing
- Software Testing
- Deterministic Simulation
- Fuzzing
- Reliability
- Distributed Systems
- SDK
apis:
- name: Antithesis Platform API (Webhooks)
  description: Programmatic access to the Antithesis autonomous testing platform via tenant-scoped webhook endpoints. POST
    /basic_test launches a test run; POST /debugging starts a multiverse debugging session. Authenticated with HTTP Basic
    machine credentials.
  humanURL: https://antithesis.com/docs/reference/rest_api/
  baseURL: https://{tenant}.antithesis.com
  properties:
  - type: APIReference
    url: https://antithesis.com/docs/reference/rest_api/
  - type: Webhooks
    url: https://antithesis.com/docs/reference/webhook/overview/
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- url: https://antithesis.com/blog/rss.xml
  type: BlogRSS
- type: Website
  url: https://antithesis.com
- type: DeveloperPortal
  url: https://antithesis.com/docs/
- type: Documentation
  url: https://antithesis.com/docs/
- type: APIReference
  url: https://antithesis.com/docs/reference/rest_api/
- type: GettingStarted
  url: https://antithesis.com/docs/getting_started/setup_guide/
- type: Blog
  url: https://antithesis.com/learn/?category=Blog
- type: GitHubOrganization
  url: https://github.com/antithesishq
- type: Support
  url: https://discord.com/invite/antithesis
- type: Login
  url: https://antithesis.com/login/
- type: TermsOfService
  url: https://antithesis.com/legal/terms_of_use/
- type: PrivacyPolicy
  url: https://antithesis.com/legal/privacy_policy/
- type: TrustCenter
  url: https://trust.antithesis.com/
- type: Authentication
  url: authentication/antithesis-authentication.yml
- type: Packages
  url: packages/antithesis-packages.yml
- type: SDKs
  url: packages/antithesis-packages.yml
- type: CLI
  url: cli/antithesis-cli.yml
- type: AgentSkill
  url: skills/_index.yml
- type: LLMsTxt
  url: llms/antithesis-llms.txt
- type: Conventions
  url: conventions/antithesis-conventions.yml
- type: Conformance
  url: conformance/antithesis-conformance.yml
- type: DomainSecurity
  url: security/antithesis-domain-security.yml
x-enrichment:
  date: '2026-07-19'
  status: backfilled
  pass: local-v1
  note: backfilled from .gitignore signal + verified work evidence

Antithesis API — frequently asked questions

Does Antithesis have an API?

Yes. APIs.io lists 1 API from Antithesis, including Antithesis Platform API (Webhooks).

How do I authenticate with the Antithesis API?

Antithesis uses bearer-token authentication (http/openIdConnect · 4 schemes). The details are profiled on APIs.io as Antithesis Authentication.

Is the Antithesis API ready for AI agents?

Antithesis has a Kin Score of 35.2 out of 100 (thin) and an Agent Readiness score of 10.0 (agent-aware), scored by API Evangelist on 2026-10-31.

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