Express
OpenJS Foundation · Web frameworks & UI
Minimal, unopinionated web framework for Node.js with routing and middleware, the long-standing default for HTTP servers in the Node ecosystem
MITOpen sourceFreeLocalSelf-hostedNov 2, 2026
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FastAPI
Sebastián Ramírez (tiangolo) and FastAPI contributors · API development & tooling
Python web framework for building HTTP APIs from type-annotated functions, with automatic validation through Pydantic and generated OpenAPI documentation
MITOpen sourceFreeLocalSelf-hostedNov 2, 2026
Hono
Hono project (Yusuke Wada and contributors) · Web frameworks & UI
Small TypeScript web framework built on Web Standard APIs that runs unchanged on Cloudflare Workers, Deno, Bun, Node.js and other JavaScript runtimes
MITOpen sourceFreeLocalSelf-hostedNov 2, 2026
Hoppscotch
Hoppscotch · API development & tooling
Open-source API client that runs in the browser or as a desktop app, supports REST, GraphQL and realtime protocols, and can be self-hosted for teams
MITOpen sourceFreeLocalSelf-hostedNov 2, 2026
Model Context Protocol
Model Context Protocol, a Series of LF Projects, LLC (originated by Anthropic) · Agent frameworks & orchestration
Open JSON-RPC standard for connecting AI applications to tools, data and prompts through servers, now stewarded under the Linux Foundation with SDKs in many languages
Open sourceOpen sourceFreeLocalSelf-hostedNov 2, 2026
Pydantic
Pydantic Services Inc. · Data quality & validation
Python data-validation library using type hints to parse, validate and serialize models, with a Rust core; the schema layer behind FastAPI and many LLM SDKs
MITOpen sourceFreeLocalBroken
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