diff --git a/AGENTS.md b/AGENTS.md
index 2d6d60d..6a9b856 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -246,6 +246,17 @@ learning_ai_notes/
 - **Sync:** `cd ../learning_ai/learning_ai_common_plat && bash scripts/sync-npmrc.sh`
 - **Key rule:** Never hardcode `gitea.bytelyst.com` — use `${GITEA_NPM_HOST:-localhost}:3300` (SSH tunnel on corp network)
 
+
+### docker-prep.sh — NEVER edit directly
+
+**`scripts/docker-prep.sh` and its `_docker-prep-*.js` helpers are managed by a canonical template in `learning_ai_common_plat`.** Never hand-edit — drift across 9 repos compounds linearly.
+
+- **Template:** `../learning_ai_common_plat/scripts/docker-prep.template.sh`
+- **Helpers:** `../learning_ai_common_plat/scripts/_docker-prep-{inject,strip}.js`
+- **Sync:** `cd ../learning_ai_common_plat && bash scripts/sync-docker-prep.sh`
+- **Drift check (CI):** `bash scripts/check-docker-prep-drift.sh`
+- **Lint:** `bash scripts/docker-doctor.sh` (or `make doctor` for both gitea-doctor + docker-doctor)
+
 ### Local package source toggle
 
 NoteLett defaults to local `@bytelyst/*` packages from `../learning_ai/learning_ai_common_plat` through `.pnpmfile.cjs`; do not use Gitea unless explicitly needed.