HarnessRouter Community Edition

I came across HarnessRouter Community Edition (Apache-2.0) and it looks like a very engineer-facing piece of agent tooling: a self-hosted “unified interface” that lets me run different agent harnesses through one API.

The pitch is straightforward. Instead of wiring separate integrations per agent runner, HarnessRouter exposes one API surface with features you’d expect in production: sessions, streaming, file passing, cancellation, and failure handling. The key detail is that it implements an open standard (Unified Harness Protocol, UHP), which is the part that should reduce vendor/tool lock-in as you swap harnesses over time.

A concrete place I can see this paying off: I’m often juggling multiple workflows during development—e.g., one harness for repo-aware coding, another for structured planning, another for a “chat + tools” loop—while my app (FastAPI + Postgres + queue/background workers) needs a stable contract. A unified router lets me keep my app logic constant while changing the underlying harness.

What I’d look at first:

- The project entry page / README for the UHP overview and the supported harness list - The “unified API” docs to understand how sessions + streaming + cancellation are represented - The config flags / environment variables for self-hosting and auth - Example requests that demonstrate streaming responses and file inputs

If you’re building a small agent platform or an internal developer toolchain, this is the kind of infrastructure that makes the rest of your system simpler, not fancier.