Mock GitHub Repositories (2026) · Open Source Tools

Open-source platform for creating safe, isolated production sandboxes for API, integration, and E2E testing.

The industry standard for API mocking in JavaScript.

orval is able to generate client with appropriate type-signatures (TypeScript) from any valid OpenAPI v3 or Swagger v2 specification, either in yaml or json formats. 🍺

Angular testing library for mocking components, directives, pipes, services and facilitating TestBed setup

Mock OAuth2/OpenID Connect server for JVM tests and Docker Compose. No security workarounds needed.

The open source, cloud native tool for API Mocking and Testing. Microcks is a Cloud Native Computing Foundation incubating project 🚀

Mockery is a simple yet flexible PHP mock object framework for use in unit testing with PHPUnit, PHPSpec or any other testing framework. Its core goal is to offer a test double framework with a succinct API capable of clearly defining all possible object operations and interactions using a human readable Domain Specific Language (DSL).

Mockoon is the easiest and quickest way to run mock APIs locally. No remote deployment, no account required, open source.

mocking library for Kotlin

:wrench: Utility library for GraphQL to build, stitch and mock GraphQL schemas in the SDL-first approach

A mock implementation of the AWS S3 API startable as Docker image, TestContainer, JUnit Jupiter extension or TestNG listener

a socket mock framework - for all kinds of socket animals, web-clients included

HTTP mocking library for Rust

A unit testing framework for TypeScript backends working with inversion of control and dependency injection

A mocking library based on the Compiler APIs (Roslyn + Mocks)

A mock IDP and SP using the OpenSAML library

A powerful desktop companion for Android & kmp (desktop, iOS) apps — inspect, debug, mock and control your app in real time. Supports OkHttp, GraphQl, WebSockets, GRPC, databases, analytics

Mocking library for CoreBluetooth framework.

✅Simple and straightforward Vuex Store mock for vue-test-utils

ESM import and globals mocking for unit tests