API design & clients

Open-source tools for designing APIs and managing schemas in a registry.

Good for

Teams that need shared API definitions and schema governance.

An integrated workspace for API design, debugging, mocking, and documentation.

Good for

Keeping API contracts and test workflows in one application.

A specification and tool ecosystem for event-driven APIs.

Good for

Documenting message channels, payloads, and asynchronous integrations.

An API client for composing requests and organizing development workflows.

Good for

Exploring HTTP APIs and testing requests during development.

A generator that turns OpenAPI descriptions into typed clients and related tooling.

Good for

Keeping frontend API calls aligned with an API specification.

A workspace for sending requests, testing APIs, and sharing API collections.

Good for

Collaborating on request examples and repeatable API checks.

Tools for validating API descriptions and publishing API documentation.

Good for

Turning OpenAPI files into a navigable developer reference.

Tools for designing and documenting APIs around shared specifications.

Good for

Reviewing API contracts before implementing endpoints.

Tools for editing, documenting, and exploring OpenAPI-described APIs.

Good for

Publishing interactive API documentation and maintaining API definitions.

A language for describing APIs and generating specifications and clients.

Good for

Maintaining an API contract that feeds multiple code generators.