Tweet by ankrgyl

April 5, 2026

The fundamental problem with this whole harness craze is that they are designed for a very specific single-player and your choice of insecure or expensive (full access to sandbox) environment. Beyond the cost, this constrains harnesses/agents to a very specific (slow chat or background work). We need to build harnesses that are both efficient and secure, and optimize those for model performance. Additional layers of power that require a sandbox can then be opt-in when needed, not default provisioned for every interaction. Maybe I'm wrong and the correct thing to do is just optimize the F out of the sandbox layer, but that seems unlikely to be efficient at scale. If an LLM's action does not need a sandbox, then managing a file descriptor to stream bytes over the network is outrageously cheaper and more secure than provisioning a virtual machine. I believe that until we build true multi-tenant harnesses, the use cases for agents will continue to be constrained to ~ coding. Which is a lot of stuff! But undersells what agents could do at scale.

Author
ankrgyl
Date
April 5, 2026
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