Cairn Framework

Part 10 of the Cairn series. Dev log 6 was the OpenAI audit. This one covers what we built since, the two audits of it, and, because we were asked for it, the pains and mistakes of the project so far, not just the progress. What got built Cairn is a tamper-evident log of what AI agents were allowed to do and what they did. Until now the log could say who may delegate a capability (invariant I11: a grant handed down must be strictly narrower than the one it came from). It could not say whether an agent then stayed inside the grant it held. That gap was written into the roadmap as "I11 only as far as delegation", and it was the next thing to close. It is closed for agents that hold a grant. Replay now checks every action an agent logs against its grant: Tool. The action type must be in the grant's tool list. Host. The host the action declares must be in the grant's host list. Expiry. A grant past its not_after time permits nothing. Budget. Each action declar...

Part 9 of the Cairn series. Dev log 5 shipped a log server and a witness. This one is about the outside review that followed: what it found, what we fixed, and what we decided not to. Every earlier audit of Cairn used Gemini, with DeepSeek on a few passes. Models from one family share blind spots, so we ran a different one. We gave gpt-5.5 the code verbatim, pasted from git diff and cat rather than retyped, in four separate passes: A: ledger, governance and the verifier. B: review, gatekeeper and providers. C: log server, witness and CI. D: every phase in the roadmap, plus every public claim in the README and docs. Each pass was asked for ranked findings, trigger conditions, tests that would pass even if the code were wrong, and documentation that overclaims. Each ran three to four minutes. We then checked every finding against the repository before changing anything. A model reviewer is a lead generator, not an oracle. Here is how the leads came out. Where it was right and...