Your Agent Might Actually Lie to You
Three parts on the hackathon build: a Stop hook that will not let a coding agent say done until a real browser agrees.
I built GuardianKane for the TestMuAI Kane CLI hackathon, where it placed 2nd. This is the story of that first version: why the gate exists, the four paired experiments that tested it, and what I found when I re-read my own logs and had to ask who checks the checker.
Start with part 01 →
- 01
Sep 21, 2026 · 8 min readMy Agent Shipped a Broken Chart and Told Me It Was Done
Two builds, one PRD. One rendered a clean performance chart. The other drew the same line twice and reported the task complete. How that gap turned a planning tool into a Claude Code Stop hook that makes the agent prove its work in a real browser, and what the gate caught first.
- 02
Sep 21, 2026 · 8 min readThe Requirement Nobody Wrote
A four-line todo PRD said priority defaults to Medium and nothing else. One build asked how a task becomes High; the other never did. Then I built a trap for the gate and both builds walked straight past it. Four paired experiments, and the pattern they drew: the gap grows with the density of the spec.
- 03
Sep 21, 2026 · 9 min readWho Verifies the Verifier?
On the densest build, eight tasks failed a browser check and one of them was a real bug. The rest were the verifier, and then my own write-up turned them into findings. Notes on checking the thing that checks, and on a three-strike retry cap the agent could quietly reset.