Agent Router — formerly Envoy AI Gateway — is an open-source gateway that gives your AI agents a single, unified API for every generative AI provider. Built on Envoy and now an Agentic AI Foundation project, it centralises provider credentials, routing, failover and token limits, so your agent speaks one API while the gateway handles the traffic. It has 2,251 stars on GitHub.
As agents grow from demos into production systems, scattering provider API keys and bespoke failover logic through your code becomes a liability. Agent Router moves all of that into configuration: describe providers, credentials, tools and limits once, and it generates the Envoy configuration that enforces them. It routes OpenAI-compatible requests to Anthropic, Bedrock, Vertex AI, Azure or self-hosted vLLM, aggregates MCP tools behind one catalog, and emits OpenTelemetry-based observability for every request — all without requiring Envoy expertise.
Agent Router is free and open source under Apache-2.0. For teams that prefer not to self-host, commercial hosted and enterprise editions built on it — such as Tetrate’s Agent Router Service and enterprise offerings — are available from partners, which makes the overall model freemium.
Agent Router suits platform teams and agent builders who need governed, observable access to multiple model providers. If you are juggling several API keys, need failover between providers, or must cap token spend per team, it replaces a pile of glue code with one proven gateway.