diff --git a/docs/agent-log.md b/docs/agent-log.md
index 3ca1649..80b1152 100644
--- a/docs/agent-log.md
+++ b/docs/agent-log.md
@@ -4,6 +4,27 @@ What agents have done, newest first. Add an entry for every piece of work: the d
 note or request it was for, what changed, the files touched, the tests run, and anything left
 open or not verified. Keep each entry short; the git history has the details.
 
+## 2026-10-27: t66 dev console (Claude Code + Codex)
+
+- Backtick opens a dev console in any build. The first time in a world it warns that the save
+  will be marked; accepting saves `dev: true` and a `devLog` (last 200 commands) in the world,
+  and the worlds list shows a "Dev console" badge. Commands: help, money, debt, give (display or
+  internal name, past the bag limit), bit, bag, unlock, tp (cursor or x y), free on|off, speed,
+  pause, step, weather clear|rain. Command logic is sim-side (`devCommand` in
+  `src/sim/devconsole.js`); the panel is `src/ui/devconsole.js`.
+- Not built: `time` (no clean way to set the time of day) and undo (commands are logged instead).
+  Free building also skips `payCost`, so ghosts built later are free too; removing a piece built
+  for free still refunds its normal cost.
+- Also fixed a flaky build-card check: the wall-material chip markup (`data-wall-picker=""`)
+  made the selection card rebuild its button every refresh.
+- Files: `src/sim/devconsole.js`, `src/ui/devconsole.js`, `src/styles/devconsole.css`,
+  `src/shell.html`, `src/manifest.json`, `src/sim/items.js`, `src/sim/save.js`, `src/sim/world.js`,
+  `src/ui/input.js`, `src/ui/loop.js`, `src/ui/saves.js`, `src/ui/session.js`,
+  `src/ui/selection.js`, `src/ui/notebook.js`, `src/ui/build-menu.js`, tests
+  `t_dev_console.js`, `t_dev_console.py`, `test/run_all.py`, `docs/PROJECT_MAP.md`.
+- Tests: `python3 test/run_all.py --browser` all passed. Built in a parallel worktree; Codex
+  hit its usage limit near the end and Claude finished it (the payCost fix).
+
 ## 2026-10-27: t67 belt drop drawn as two capped ends (Claude Code)
 
 - A flat belt feeding an uphill belt's low end on the same row (and two uphill slopes side by