typicode/json-server

mock REST API with a simple JSON file

mock API servers for development and testing
mockoon/mockoon
API client with HTTP interception and mocking
requestly/requestly
cross-platform API client for testing, visualizing, and integrating APIs
foss42/apidash
HTTP endpoints for testing clients and APIs
sharat87/httpbun
type-safe API contracts for REST, no codegen
ts-rest/ts-rest
web-based API testing and collaboration tool
hoppscotch/hoppscotch
HTTP testing tool with HTTP/2 and HTTP/3 support
alexandrehtrb/Pororoca
generate Go interface mocks automatically
vektra/mockery
cross-platform API testing client for REST and GraphQL
httpie/desktop
Better fetch API that works everywhere with smart JSON parsing and auto retry
unjs/ofetch