CopilotKit / aimock
Mock everything your AI app talks to — LLM APIs, MCP, A2A, AG-UI, vector DBs, search. One package, one port, zero dependencies.
CopilotKit / aimock
karatelabs / karate
Test Automation Made Simple
mockoon / mockoon
Mockoon is the easiest and quickest way to run mock APIs locally. No remote deployment, no account required, open source.
wiremock / wiremock
A tool for mocking HTTP services
AliSoftware / OHHTTPStubs
Stub your network requests easily! Test your apps with fake network data and custom response time, response code and headers!
stoplightio / prism
Turn any OpenAPI2/3 and Postman Collection file into an API server with mocking, transformations and validations.
mock-server / mockserver-monorepo
MockServer is an HTTP(S) mock server and proxy for testing that lets you mock APIs, inspect and modify live traffic, and inject failures. It supports HTTP/1.1, HTTP/2, gRPC, WebSockets, TCP and more on a single port, with additional support for HTTP/3, message brokers, and AI/LLM APIs.
fabric8io / kubernetes-client
Java client for Kubernetes & OpenShift
microcks / microcks
The open source, cloud native tool for API Mocking and Testing. Microcks is a Cloud Native Computing Foundation incubating project 🚀
unkn0wn-root / resterm
Terminal API client for HTTP, GraphQL, gRPC, WebSocket and SSE. Plain .http files you can diff and version, with scripted tests, workflows, mocks, recorder, and a CLI runner for CI.
wiremock / WireMock.Net
WireMock.Net is a flexible product for stubbing and mocking web HTTP responses using advanced request matching and response templating. Based on WireMock Java, but extended and different functionality. Full documentation can be found at https://wiremock.org/dotnet/.
smocker-dev / smocker
Smocker is a simple and efficient HTTP mock server and proxy
httptoolkit / mockttp
Powerful friendly HTTP mock server & proxy library
dotnet / dev-proxy
Simulate API failures, throttling, and chaos — all from your command line.
greenmail-mail-test / greenmail
Official master for the Greenmail project
httpmock / httpmock
HTTP mocking library for Rust
Pikopod / pikopod
A sandbox for the third-party APIs you depend on. Built from the provider's spec, it fails on purpose, and it replays the exact failure production hit.
sinyu1012 / proxypin-mcp-workbench
基于 ProxyPin 与 MCP 的自动化抓包、API 分析、Mock 场景和数据归档工作台，支持 移动端/Mac端 抓包并通过 MCP 让 AI 自动分析获取内容 / Mock 一系列接口。
weihubeats / RustFox
A high-performance, local-first API client & Postman alternative built with Rust, Tauri 2, and Vue 3.高性能、本地优先的 API 调试与测试客户端 (Postman/Insomnia/ApiFox 替代品)，基于 Rust + Tauri 2 + Vue 3 打造。
axium-lab / llm-mock
Self-hosted OpenAI-compatible mock server — test your LLM integrations without exposing your API key. By Axium.
shriramkv / mcp-mock-server
A zero-dependency, configurable mock MCP server for testing MCP clients and harnesses. Serves a correct MCP handshake over stdio (initialize, tools/list, tools/call). You describe tools and canned responses in a JSON file. Simulates errors and missing-argument handling. Perfect target for your existing conformance, audit, and load-test tools.