Harness Router is a decision layer for AI coding agents that makes tool selection faster, cheaper, and more reliable before execution. Use it as a Codex hook to automatically route every tool call, or as a skill when the agent should invoke routing explicitly. Obvious decisions stay on the fast path, ambiguous choices are resolved with Jev, and complex multi-step decisions can escalate to MCTS.
I built Harness Router to solve a problem I kept seeing in agentic systems: models spending too much time, tokens, and money deciding which tool to call.
The idea is simple: obvious calls take the fast path, ambiguous calls can use Jev, and harder multi-step decisions can use bounded MCTS.
You can integrate it directly as a routing layer, expose it through MCP, or use Codex hooks so tool selection is checked automatically before execution. With SessionStart + PreToolUse, Codex can discover its available tools once and route or re-plan calls through Harness Router transparently.
It’s framework-agnostic and fully open source.
I’m especially interested in feedback from people building coding agents, MCP servers, Codex workflows, or other tool-heavy agent systems. If you try it, I’d love to hear where the routing works well—and where it breaks. 🚀
About Harness Router on Product Hunt
“Fast AI tool routing powered by Jev.”
Harness Router launched on Product Hunt on September 28th, 2026 and earned 79 upvotes and 2 comments, placing #17 on the daily leaderboard. Harness Router is a decision layer for AI coding agents that makes tool selection faster, cheaper, and more reliable before execution. Use it as a Codex hook to automatically route every tool call, or as a skill when the agent should invoke routing explicitly. Obvious decisions stay on the fast path, ambiguous choices are resolved with Jev, and complex multi-step decisions can escalate to MCTS.
On the analytics side, Harness Router competes within Open Source, Developer Tools and Artificial Intelligence — topics that collectively have 1.1M followers on Product Hunt. The dashboard above tracks how Harness Router performed against the three products that launched closest to it on the same day.
Who hunted Harness Router?
Harness Router was hunted by Kamil Mosciszko. A “hunter” on Product Hunt is the community member who submits a product to the platform — uploading the images, the link, and tagging the makers behind it. Hunters typically write the first comment explaining why a product is worth attention, and their followers are notified the moment they post. Around 79% of featured launches on Product Hunt are self-hunted by their makers, but a well-known hunter still acts as a signal of quality to the rest of the community. See the full all-time top hunters leaderboard to discover who is shaping the Product Hunt ecosystem.
For a complete overview of Harness Router including community comment highlights and product details, visit the product overview.
Kamil Mosciszko
Hey Product Hunt 👋
I built Harness Router to solve a problem I kept seeing in agentic systems: models spending too much time, tokens, and money deciding which tool to call.
The idea is simple: obvious calls take the fast path, ambiguous calls can use Jev, and harder multi-step decisions can use bounded MCTS.
You can integrate it directly as a routing layer, expose it through MCP, or use Codex hooks so tool selection is checked automatically before execution. With SessionStart + PreToolUse, Codex can discover its available tools once and route or re-plan calls through Harness Router transparently.
It’s framework-agnostic and fully open source.
I’m especially interested in feedback from people building coding agents, MCP servers, Codex workflows, or other tool-heavy agent systems. If you try it, I’d love to hear where the routing works well—and where it breaks. 🚀