oRPC combines RPC and OpenAPI to create APIs that are type-safe from client to server. It supports contract-first development and integrates with various frameworks and tools for enhanced observability and usability. The documentation provides clear examples for setting up servers, clients, and generating OpenAPI specifications.

Pulumi Cloud REST API has adopted OpenAPI 3.0, providing a machine-readable specification for the API. This allows for better tooling, client generation, and documentation, ensuring that the API is consistently represented and easier to use. You can access the OpenAPI spec directly via a GET request.

Scalar is a minimal and powerful open-source API reference tool that seamlessly integrates with various API frameworks and offers first-class OpenAPI support. It features a user-friendly interface, dynamic parameter handling, and the ability to save requests in organized collections while providing managed hosting options for API documentation. The platform is designed for developers, featuring a modern design and a range of plugins and integrations across multiple programming languages and frameworks.