Open source API Development & Testing tools
18 free, open source options sorted by GitHub stars.
HoppscotchSleek, intuitive API development and testing platformBrunoLightweight, fast, and open-source API client for developersInsomniaPowerful API development and testing made effortlessYaakFast, secure, offline API client with Git integrationApache APISIXHigh-performance API gateway with built-in LLM supportTykUniversal API management for REST, GraphQL, gRPC & asyncMockoonEffortless API mocking for seamless developmentRequestlyIntercept, modify, and debug HTTP(S) requests effortlesslyUnKeySecure, scalable API key management for developersHTTPieModern command-line HTTP client for the API eraKrakendBlazing-fast API gateway with linear scalabilityFirecampUnified API development ecosystem for modern teamsFusioAPI management platform for developers and AI agentsVoidenBuild APIs like code with Git-native workspaceTailcallThe modern GraphQL runtimeWunderGraphUnify APIs, databases, and services effortlesslyHiveOpen-source GraphQL federation platformGraviteeUnified API, event, and AI agent management platform