Hey, have you heard about the latest update to Plano? It’s version 0.4.3, and it’s bringing some exciting changes to the table. As someone who’s interested in making workflows more efficient, I think you’ll find this pretty interesting.
So, what’s new in Plano 0.4.3? Two main things: Filter Chains and OpenRouter Integration. Let’s break them down.
Filter Chains are a way to capture reusable workflow steps in the data plane. Think of it like a series of mutations that a request flows through before reaching its final destination. Each filter is a network-addressable service that can inspect, mutate, or enrich the request. It’s like having a lightweight programming model over HTTP for building reusable steps in your agent architectures.
Here are some key things that Filter Chains can do:
* Inspect the incoming prompt, metadata, and conversation state
* Mutate or enrich the request (like rewriting queries or building context)
* Short-circuit the flow and return a response early (like blocking a request on a compliance failure)
* Emit structured logs and traces for debugging and improvement
The other major update is the introduction of Passthrough Client Bearer Auth. This allows Plano to forward the client’s original Authorization header to the upstream service, instead of using a static access key. It’s useful for deploying Plano in front of LLM proxy services that manage their own API key validation.
Some potential use cases for this include:
* OpenRouter: Forward requests to OpenRouter with per-user API keys
* Multi-tenant Deployments: Allow different clients to use their own credentials via Plano
Overall, these updates seem like a step in the right direction for making Plano more powerful and flexible. If you’re working with agent architectures or LLM proxy services, it’s definitely worth checking out.









