sudorandom/fauxrpc

High-performance, multi-protocol mock server. HTTP, WebSocket, gRPC, MQTT, SSE, GraphQL, SOAP in one binary.

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.

mocker-api that creates mocks for REST APIs. It will be helpful when you try to test your application without the actual REST API server.

httpbin like for gRPC

Turn an OpenAPI spec into a local API in one command. Build and test your frontend with custom responses, shared state, and simulated failures, without waiting for the backend.

Fake JSON Server is a Fake REST API that can be used as a Back End for prototyping or as a template for a CRUD Back End.

Mockoon is the easiest and quickest way to run mock APIs locally. No remote deployment, no account required, open source.

Free, 10.5MB, containerized, self-hosted mock server.

Easy Setup Stub Server