diff --git a/README.md b/README.md
index 50199b4..07bdc2a 100644
--- a/README.md
+++ b/README.md
@@ -4,6 +4,10 @@
 
 **The package manager for AI agents.**
 
+> [!WARNING]
+> agr is no longer maintained. Use [skills.sh](https://skills.sh/) and its
+> [`skills` CLI](https://skills.sh/docs/cli) for skill management instead.
+
 For teams who want to manage agent skills like software packages — the way npm,
 PyPI, and uv manage code. Install skills from any Git repo into Claude Code,
 Cursor, Codex, and more, then share them across your team like real dependencies.
diff --git a/docs/diary/2026-07-12-mark-agr-unmaintained.md b/docs/diary/2026-07-12-mark-agr-unmaintained.md
new file mode 100644
index 0000000..0b5ded7
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+++ b/docs/diary/2026-07-12-mark-agr-unmaintained.md
@@ -0,0 +1,54 @@
+# Diary: Mark agr as unmaintained
+
+Make the project's maintenance status unmistakable and direct users to the
+replacement skill-management tool.
+
+## Step 1: Add the maintenance notice
+
+**Author:** main
+
+### Prompt Context
+
+**Verbatim prompt:** let's execute on TODO.md
+
+**Interpretation:** Mark agr as no longer maintained as part of adopting
+skills.sh.
+
+**Inferred intent:** Prevent new users from adopting agr and give existing
+users a clear replacement.
+
+### What I did
+
+I added a prominent warning near the top of `/README.md` stating that agr is no
+longer maintained and linking to skills.sh and its CLI documentation.
+
+### Why
+
+The README is the first place existing and prospective users look for project
+status and installation guidance.
+
+### What worked
+
+The notice fits the existing README structure and leaves historical usage
+documentation available to existing users.
+
+### What didn't work
+
+Nothing failed during this step.
+
+### What I learned
+
+The repository had no existing deprecation or maintenance-status notice.
+
+### What was tricky
+
+The notice needed to be prominent without rewriting the historical project
+documentation.
+
+### What warrants review
+
+Review the warning at the top of `/README.md` and verify both replacement links.
+
+### Future work
+
+No further development is planned for agr.