Can AI Agents Prove What They Did?

Sun, 09 Aug 2026 00:00:00 +0000

Today I am releasing Bellbook, an open-source Rust library for creating tamper-evident, replay-verifiable records of captured AI agent activity.

It started with a simple problem. As agents take real actions - calling tools, changing software, spending money, operating across company systems - we increasingly depend on their own account of what happened.

The agent says it followed the request. The runtime says the tool call succeeded. A dashboard shows green. A log contains a sequence of events. None of those, on their own, give another party a portable way to check the claim.

About

Mon, 01 Jan 0001 00:00:00 +0000

I’m Cristian Ducu. I work on open-source infrastructure for agent evaluation, verifiable execution, and autonomous software development.

My first OSS project is Bellbook, a tamper-evident, replay-verifiable record of captured agent activity.

You can also find me on LinkedIn, and X.