Twitter/X

Author @ankrgyl and collaborators Alex Krentsel and Martin Casado have been…

2026-07-16 · 18:14 UTC ·@ankrgyl ·0 min read

Brief

Ankrgyl, Alex Krentsel, and Martin Casado have been prototyping a split architecture for agents that isolates semantic functions (like compaction and subagents) from systems concerns (event storage, sandboxes, and turn coordination). Their joint project, Exo, is described as an open-source self-modifying agent that learns environments, adapts policies, and optimizes costs, with development ongoing over the past few months (announced 2026-07-16).

Why it matters

Author @ankrgyl and collaborators Alex Krentsel and Martin Casado have been developing a design that separates the agent harness into a semantic layer (compaction, subagents) and a systems layer (event storage, sandboxes, turn coordination).

Key details

  • Alex Krentsel announced Exo, an open-source agent that can rewrite itself, learn new environments, adapt policies, optimize costs, and play games; the project is a joint effort between @AlexKrentsel, @martin_casado (a16z), and @ankrgyl (Braintrust).
Source evidence

I've been jamming on this funky idea with @AlexKrentsel and @martin_casado for the past few months. The basic idea was to separate the semantic part of the harness (eg compaction, subagents) from the systems part (event storage, sandboxes, and turn coordination).

(1/n)

Alex Krentsel (@AlexKrentsel)

Introducing Exo 🦋 – an open-source agent that can rewrite every part of itself. It learns new environments, adapts policies, even optimize costs (and play games!!)

We've been hacking away at this project with @martin_casado from @a16z and @ankrgyl from @braintrust and friends.

— https://nitter.net/AlexKrentsel/status/2077786601418322344#m