Bifrost
Bifrost (Maxim AI) is an open-source AI gateway written in Go that exposes 20+ providers, including OpenAI, Anthropic, AWS Bedrock, and Google Vertex, through a single OpenAI-compatible API, with automatic fallbacks, load balancing, semantic caching, virtual keys and budgets, MCP tool access, and Prometheus metrics and tracing. Self-hosted via npx or Docker under Apache 2.0; clustering, adaptive load balancing, and guardrails are part of the enterprise edition.