Hey Product Hunt—I’m Tyler, the person building Arbiter. I wanted to own the agent harness I was using: the agents, their tools, their state, and the runtime connecting everything. I didn’t want those pieces hidden behind a hosted chat interface. So I've been building Arbiter. It’s one native binary with three ways to use the same agents: a multi-pane terminal, a one-shot CLI for scripts and CI, and an HTTP+SSE server. Agent behavior lives in editable constitutions that define the model, role, rules, and allowed tools. Everything is stored locally under ~/.arbiter/. You can use Ollama or bring a hosted provider. The network is optional. Arbiter is still pre-1.0, and I’m building it on my own. I’d really value feedback from people using agents for actual work—especially where the runtime feels useful, confusing, or incomplete.

Arbiter

The agent runtime that lives on your machine

The agent runtime that lives on your machine