Best Open Source LLM API Gateways

LiteLLM is the leading open source LLM gateway, supporting over 100 different LLM providers through a unified OpenAI-compatible API. Built with Python, it offers enterprise-grade features while remaining completely free and self-hostable. The project maintains active development with regular updates and strong community support.

Part of the LangChain ecosystem, this gateway provides seamless integration with LangChain applications while supporting multiple LLM providers. It offers advanced features like prompt management, conversation memory, and chain orchestration through a well-documented API interface.

Built on Envoy proxy technology, Gloo AI Gateway delivers exceptional performance for cloud-native deployments. It provides Kubernetes-native configuration, advanced traffic management, and seamless integration with service mesh architectures. Perfect for organizations heavily invested in container orchestration.

LocalAI is a self-hosted, OpenAI-compatible API gateway that runs entirely locally without requiring external API calls. It supports various open-source models including LLaMA, GPT-J, and others. Perfect for privacy-focused deployments and organizations requiring complete control over their AI infrastructure.

Ollama provides a simple yet powerful way to run large language models locally. Its gateway component exposes an OpenAI-compatible API, making it easy to integrate with existing applications. The project focuses on simplicity and ease of use while maintaining performance and flexibility.