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 publishes 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 14 more developer resources.

🌐 Visit website 📡 Source on GitHub
32.7/100 thin Agent 14/100 human only Full breakdown ↓
scored 2026-07-20 · rubric v0.4
1 APIs 0 Features
CompanyDeveloper ToolsTestingSoftware TestingDeterministic SimulationFuzzingReliabilityDistributed SystemsSDK

API Rating

API Evangelist API Evangelist Rating How this is scored →
scored 2026-07-20 · rubric v0.4
Composite quality — 32.7/100 · thin
Contract Quality 0.0 / 25
Developer Ergonomics 14.3 / 20
Commercial Clarity 8.4 / 20
Operational Transparency 0.7 / 13
Governance 0.0 / 12
Discoverability 9.3 / 10
Agent readiness — 14/100 · human only
Machine-Readable Contract 0 / 18
Agentic Access Contract 0 / 15
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 0 / 6
Agent Skills 5 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 0 / 3
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/antithesis: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs

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 ...

Resources

Get Started 3

Portal, sign-up, and the first successful call

DeveloperPortal
DeveloperPortal
 GettingStarted
GettingStarted
 Login
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
GitHubOrganization
 Packages
Packages
 SDKs
SDKs
 CLI
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 2

The organization behind the API

Website
Website
 Blog
Blog

Source (apis.yml)

apis.yml Raw ↑ 
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
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: '0.20'
created: '2026-07-17'
modified: '2026-07-17'
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:
- 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