diff --git a/AGENTS.md b/AGENTS.md
index a24b2615..be5e05da 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -2,6 +2,10 @@
 
 Preserve the independent Admin package build and access-controlled project knowledge surfaces.
 
+## Branch and deployment boundary
+
+`main` is the only production branch and maps only to the `production` deployment environment. `staging` is the only development-integration branch and maps only to the `staging` deployment environment. Short-lived pull-request branches may validate without deploying, but they must never define another deployment environment. Do not create or use `development`, `preview`, `stable`, or any other GitHub deployment environment; preview deployments are prohibited. Release tags may promote an exact reviewed `staging` commit to `production` without creating another branch or environment. Artifact channel names must never become GitHub deployment environments.
+
 ## Project library
 
 Use `trsd library show admin` and `status` before querying `treeseed-ai/admin-library`. Read root-level paths at an exact commit. Author only through governed library workspaces and reviews. Never recreate a library `src/content` tree or edit `.treeseed/data` directly.