Every gateway ships with a set of built-in policies. Authentication. Rate limiting. Request routing. Prompt guards. These cover most use cases. But what about the ones they don’t cover?
What if you need to add a custom header based on a database lookup? What if you need to transform a request body in a way no existing filter supports? What if your business has unique logic that no off-the-shelf gateway can anticipate?
You build your own extension.
This article walks through exactly how to do that using agentgateway, Envoy, and Rust. In this tutorial, you’ll learn how to:
- Build a custom Envoy dynamic module in Rust
- Package it into a production-ready Docker image
- Deploy it to Kubernetes with kgateway and agentgateway
- Test the entire stack with a mock LLM endpoint
