Guanlan Dai(@guanlan):Exo Harness now runs natively on Runta. In FrontierHarness Eval, Exo was cheapest per completed task at $1.05. On the hardest task it hit its 51-step cap and quit at $1.46 while others kept spending. That is the harness you let rewrite itself. Exo's Executor holds no durable state, so the agent can modify it. History, artifacts, secrets and sandbox lifecycle sit in the Harness, out of reach. Runta provides a resumable environment, so the Exo Harness can self-evolve freely. Exo never holds the model API key, only a stub. Our egress gateway injects the real one at the provider. Code the agent wrote can read whatever the Executor can, and all the Executor has is a stub.

2026.09.10 17:37

Exo Harness now runs natively on Runta. In FrontierHarness Eval, Exo was cheapest per completed task at $1.05. On the hardest task it hit its 51-step cap and quit at $1.46 while others kept spending. That is the harness you let rewrite itself. Exo's Executor holds no durable state, so the agent can modify it. History, artifacts, secrets and sandbox lifecycle sit in the Harness, out of reach. Runta provides a resumable environment, so the Exo Harness can self-evolve freely. Exo never holds the model API key, only a stub. Our egress gateway injects the real one at the provider. Code the agent wrote can read whatever the Executor can, and all the Executor has is a stub.