KestKest
Open Source · Self-Hostable · AI-Native

The open-source
Postman alternative.

API documentation, testing, and end-to-end automation in one platform.Ship APIs with confidence — from design to production.

Kest Platform — API Workspace
Collections
User Auth Flow
Payment API
Notification Service
Search API
Environments
Development
Staging
Production
POST/api/v1/auth/login200 OK · 89ms
Request Body
{
"email": "admin@kest.dev",
"password": "••••••••"
}
Response
{
"token": "eyJhbGci...",
"user": {
"id": 42,
"role": "admin"
}
}
status == 200 body.token exists↳ Captured: token
Self-host or cloud Your data, your servers AI-powered testing CLI + Web in sync OpenAPI compatible

Design. Test. Automate. Ship.

Kest unifies the entire API lifecycle into one open platform — from writing your first endpoint doc to running E2E tests in CI/CD.

API Documentation

Design & Collaborate

  • Visual API editor with OpenAPI 3.0 support
  • Real-time team collaboration
  • Auto-generated, always up-to-date docs
  • Import from Swagger, Postman, cURL

API Testing

Test & Debug

  • Send requests with one click or one command
  • Variable chaining across requests
  • Assertions, captures, and validations
  • AI diagnoses failures automatically

E2E Automation

Automate & Ship

  • Markdown-based flow files (.flow.md)
  • Multi-step scenarios with dependencies
  • CI/CD integration out of the box
  • Replay, diff, snapshot, and mock

Web + CLI. One platform.

Design APIs in the browser. Test them from the terminal. Everything stays in sync.

Web Platform

For teams that collaborate

  • Visual API editor — no YAML wrangling
  • Multi-environment management (dev / staging / prod)
  • Team workspaces with role-based access
  • Version history and change tracking
  • One-click request testing in browser
  • Auto-generated shareable documentation

Kest CLI

For developers who ship fast

  • Replaces curl — readable, chainable, recordable
  • AI-powered: kest why / suggest / gen
  • Markdown flow files for E2E test automation
  • Auto-record to SQLite — replay, diff, mock
  • Watch mode for TDD-style API testing
  • Sync with platform: kest sync --project

From zero to tested in 4 steps

01

Define your APIs

Use the web editor or import from OpenAPI/Swagger. Set up environments, variables, and team permissions.

02

Sync to your machine

One command pulls your entire project — endpoints, environments, and configs — to your local workspace.

$ kest sync --project my-api
03

Write & run tests

Write .flow.md files or use the CLI directly. AI generates test flows from natural language descriptions.

$ kest run tests/*.flow.md
04

Automate in CI/CD

Drop Kest into your pipeline. Every push triggers API tests. Failures get AI-diagnosed automatically.

$ kest run --ci --report junit

Kest vs. the rest

See why teams are switching to Kest.

FeatureKestPostmanHoppscotchInsomnia
Open Source
Self-Hostable
CLI-First Testing
AI-Powered Debugging
Markdown Test Files
Auto-Record to SQLite
Mock Server from History
Snapshot Testing
E2E Flow Automation
Team Collaboration
Free for Teams

Why open source matters

Your API data is your business. It should never be locked in someone else's cloud.

Data Sovereignty

Self-host on your infrastructure. Your requests, your tokens, your servers.

Full Transparency

Audit every line of code. No telemetry surprises. No vendor lock-in.

Local-First

Works offline. SQLite storage. No cloud dependency for core features.

Community-Driven

Built by developers, for developers. Contribute, extend, customize.

Stop paying for API testing.

Kest is free, open-source, and built for teams that move fast.
Start in 30 seconds.

No credit card required · Self-host or use our cloud · MIT License