HarnessRouter is an open-source unified interface that lets product teams plug Codex, Claude Code, Hermes, and other supported agent harnesses into their products through one Agent API. It enables them to build and scale agent-powered products quickly without managing separate agent backends.
This is the 5th launch from HarnessRouter. View more
HarnessRouter Community Edition
Launched this week
Plug-and-play managed agent harnesses in your product: Codex, Claude Code and Hermes through one API on your infrastructure, now open sourced under Apache 2.0. Switch harnesses without rebuilding your backend. Sessions, streaming, files, artifacts, cancellation, failure recovery, all handled. Model provider keys, state, and deliveries under your control. Gateway, Runner, Console in one Docker container. Ready-to-use starter kit apps as inspiration of possibilities.
Free
Launch Team / Built With
Lancepilot
HarnessRouter
@priyankamandal That's a fair way to think about it, and honestly a good metaphor. What makes plugins work anywhere (browsers, editors, VS Code) is never the plugins themselves, it's a stable socket: a contract stable enough to build against, plus a way to ask "what can this one do." That's exactly what UHP is trying to be for harnesses. Integrate the socket once, and each harness plugs in with its own strengths declared upfront. The part the metaphor captures best is why it matters: nobody rewrites their editor when a new extension ships. A new harness should be a config change, not a backend rebuild. That's the whole bet.
Can a session started with one harness be continued with another, or does switching only happen between tasks?
HarnessRouter
@german_merlo1 Sessions are pinned to their harness by design: continuing a session with a different one fails loudly with a structured error (409 harness_mismatch) rather than silently starting a new conversation, because a session carries conversational context plus a working directory of files, and another harness can't genuinely inherit the first one's conversation state. Switching happens between tasks: download the artifacts (or the whole workspace as a zip), start a task on the other harness with those files as input, and continue from there. Files transfer cleanly; conversation memory intentionally doesn't. We'd rather make the boundary explicit than pretend continuity that isn't real.
AgentX - Multi-agent and eval framework
Awesome launch! Taming failure recovery, streaming, and session state across different harnesses into a single protocol is top-tier work. Rooting for you @renchu_song from the agent space!
HarnessRouter
@marcin_michalak Thank you so much for your support, Marcin! I see a huge synergy between the HarnessRouter being an intelligent unit layer, and AgentX's multi-agent orchestration as a mesh layer on top, together we will be form a complete solution for Level 5 of AI: AI Organizations, which is the ultimate step in OpenAI's 5 level AI roadmap
HarnessRouter
@renchu_song @marcin_michalak Thanks Marcin for supporting HarnessRouter team!
HarnessRouter
@renchu_song Love the idea of treating agent harnesses as infrastructure rather than rebuilding one for every product.
The “OpenRouter for agent harnesses” analogy makes a lot of sense. Codex, Claude Code, Hermes behind one API + a unified protocol could be a really powerful primitive for the next generation of agentic apps.
Excited to see this go beyond coding agents. 🚀
HarnessRouter
@eric_epsilla Thank you Eric! Yes, as we discussed internally at Epsilla, Harness-as-a-Service is the core infrastructure component and fastest way to bring intelligence into application layer. Thinking of a whole computer, harness is the CPU, data/knowledge is the Disk/Memory, horizontal agent platform is the OS, and domain vertical applications are softwares. Being able to leverage HarnessRouter as one of the core components is the competition advantage for Epsilla being an AI-native company.
HarnessRouter
@renchu_song Congratulations. And happy product launch.
HarnessRouter
@huisong_li Thank you for your support, Huisong! Your support means a lot to us :D
10xlaunch.ai
Really like that you’re building this in public and putting the infrastructure out there. Proper open source. Nice job!
HarnessRouter
@nir0b Thank you for your support, Nirob!