Best API Gateways & Backends GitHub Repositories

The agentic CLI for the entire Cloudflare API

Backend.AI is a streamlined, container-based computing cluster platform that hosts popular computing/ML frameworks and diverse programming languages, with pluggable heterogeneous accelerator support including CUDA GPU, ROCm GPU, Gaudi NPU, Google TPU, GraphCore IPU and other NPUs.

Local gateway for Claude Code, Codex and other AI clients on macOS, Windows and Linux: switch upstreams without touching clients, keep API keys from relays, cut off malicious tool calls, trace every request.

Build SMS applications with Python

The main component of AI DIAL, which provides unified API to different chat completion and embedding models, assistants, and applications

Open-source local AI SDK - run AI on-device with no cloud, no API keys. Supports GGUF, RAG, image, music, and video generation, speech-to-text, P2P inference, and more. Cross-platform: Linux, macOS, Windows, Android, iOS.

The Internet's first Poetry API

The Janssen Project is a home for open source IAM components, featuring Auth Server (OAuth/OpenID), Agama low-code identity orchestration, and the Cedarling policy decision point. The "Janssen Server" distributions bundle IAM components under one control plane.

API Gateway bridging modern and legacy APIs with WSDL-to-OpenAPI, SOAP-to-REST, XML, OAuth2, and GraphQL.

Open-source multi-provider AI gateway for Claude Code and other coding agents, with model routing, streaming, tools, reasoning, fallbacks, and local model support

See what every AI coding agent on your machine is doing, and whether the API behind it is the one you paid for. Claude Code, Codex, Cursor, Gemini CLI and more: one endpoint for 44 model vendors, A–F API authenticity grading, per-agent permissions, usage and prompt records.

Microservices library - scalecube-services is a high throughput, low latency reactive microservices library built to scale. It features: API-Gateways, service-discovery, service-load-balancing, the architecture supports plug-and-play service communication modules and features. built to provide performance and low-latency real-time stream-processing

Kuvasz (pronounce as [ˈkuvɒs]) is an open-source uptime and SSL monitoring service, with multiple notification channels, status pages, IAC support via YAML, Prometheus integration, a complete REST API and many more!

Database connectivity API standard and libraries for Apache Arrow

The open-source context layer for your AI. Catalog your tables, topics, queues and APIs then expose real metadata to your AI agents.

Can AI engines cite your site, and do they? Free 0–100 readiness score on an open GEO rubric, plus citation tracking via the OpenAI, Perplexity, Gemini and Claude APIs with your own keys. Zero dependencies, MCP server.

🔥 Next.js (React) headless eCommerce site with Typescript, WordPress (WooCommerce) backend and Algolia search

OpenTelemetry Ruby API & SDK, and related gems

Feather is a modern Swift-based Content Management System.

Reference implementation of an apiserver for a custom Kubernetes API.