All writing

Product · 11 June 2026 · 3 min read

The ledger is the product

We spent longer on the record of what the agent did than on the agent.

The first version of Anvil had a chat interface and a spinner. It worked, and nobody trusted it, because nobody could see what it had done.

What we built instead

One append-only ledger. Every read, every decision, every write, with the rule version and the approver. It is the first screen, not a settings page, and it is the thing customers show their auditors.

The agent is replaceable. Models change every few months. The record of what happened in your systems is not.