C API GitHub Repositories (2026) · Open Source Tools

A collective list of free APIs

Typesafe APIs Made Simple 🪄

Rust bindings for the Python interpreter

A collaborative list of public APIs for developers

Engine-agnostic LLM gateway in Rust. Full OpenAI & Anthropic API compatibility across vLLM, TRT-LLM, TokenSpeed, SGLang, OpenAI, Gemini & more. Industry-first gRPC pipeline, KV cache-aware routing, chat history, tokenization caching, Responses API, embeddings, WASM plugins, MCP, and multi-tenant auth.

Self-hosted geospatial data catalog with semantic search (pgvector), OGC/STAC APIs, and map builder. Built on FastAPI, PostGIS, React, and MapLibre.

Pure Go implementation of the WebRTC API

ThunderAI is a Thunderbird Addon that uses the capabilities of ChatGPT, Gemini, Claude or Ollama to enhance email management.

AI suite powered by state-of-the-art models and providing advanced AI/AGI functions. Includes AI personas, AGI functions, world-class Beam multi-model chats, text-to-image, voice, response streaming, code highlighting and execution, PDF import, presets for developers, much more. Deploy on-prem or in the cloud.

Easily access public holidays for 200+ countries via .NET, REST API, Docker, or NuGet for online and offline use.

A collaborative list of resources for developers

The first open-source AI-driven tool for automatically generating system-level test cases (also known as fuzzing) for web/enterprise applications. Currently targeting whitebox and blackbox testing of Web APIs, like REST, GraphQL and RPC (e.g., gRPC and Thrift).

An intermediary api aimed at easing development of multiplatform mods.

API desarrollada en EsJS para las diferentes cotizaciones de Dólar en Argentina, Chile, Venezuela, Uruguay, México, Bolivia, Brasil y Colombia

API pública para diferentes datos de Argentina

Open-source C++17 engine for backtesting and forward execution, with a versioned C ABI and PineScript v6 through code generation. Against TradingView's own trade lists, all 7,989 graded probes (309 open-corpus strategies, 741 closed-test scripts, 18 market/timeframe lanes) grade excellent or strong: 7,905 excellent, 84 strong. Apache-2.0.

Fabric API implemented on top of NeoForge

XDAGJ is an implementation of XDAG in Java. https://xdag.io

A live Hong Kong smart-city dashboard on public APIs. Harbour crossing minutes, strategic-road speed, street cameras, works, incidents, eight land control points, and Observatory warnings, drawn as one map. Traditional Chinese and English. Made in 24 hours with Cursor and Grok 4.7, for Agentic Engineer classes and guest lectures.

Devin upstream → OpenAI Responses / Anthropic Messages compatible API proxy