Open Source API Development & Testing Software
API Development & Testing tools provide environments for designing, debugging, and documenting application interfaces. These tools handle requests across protocols like REST, GraphQL, and WebSockets to verify that endpoints return the correct data. This type of software is for developers who need to manage traffic routing and test microservices. Self-hosting these apps ensures that sensitive request headers, authentication tokens, and internal endpoint schemas remain on private infrastructure. This approach allows teams to version control their API collections using local files instead of relying on external cloud storage.
This page lists 42 open source tools in the API Development & Testing category. The most popular are Hoppscotch, Caddy and Traefik. Most use the Apache-2.0 or MIT license, and 34 offer an official Docker image.
Ferron
A memory-safe web server written in Rust with automatic TLS certificate acquisition and renewal.
AntigravityManager
Manage multiple Google Gemini and Claude AI accounts with automated switching and real-time quota monitoring.
OpenRouteService
A customizable routing engine providing directions, isochrones, and distance matrices using OpenStreetMap geographic data.
Envoy AI Gateway
A gateway for routing application traffic to generative AI services with support for over sixteen LLM providers.
DreamFactory
A self-hosted data access platform that automatically generates governed REST APIs from various data sources.
Routr
A lightweight SIP proxy, location server, and registrar for scalable telephony and communication service infrastructure.
Voiden
An offline API workspace that uses plain text files to unify requests, documentation, and tests.
Open Trashmail
Self-hosted temporary email solution for receiving messages via web interface, JSON API, and RSS feeds.
Para
Multitenant backend server for object persistence and retrieval to accelerate web and mobile app development.
Graphweaver
Connect multiple data sources into a single GraphQL API with customizable resolvers and an admin panel.
WebHook Tester
Debug and test webhooks and HTTP requests using unique, randomly generated URLs and customizable responses.
Formance
A modular developer platform for building custom financial flows and managing internal transactions with provider agnostic infrastructure.
Join our newsletter to get shiny new open source software delivered to your inbox. Unsubscribe anytime.