diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
new file mode 100644
index 0000000..0f13f51
--- /dev/null
+++ b/CONTRIBUTING.md
@@ -0,0 +1,45 @@
+# Contributing
+
+## Propose changes
+
+Open a pull request against `develop`. Keep the default branch for releases and
+stable tips; land work on `develop` first.
+
+Point at an existing issue when one fits. Prefer a short issue that states the
+symptom or request before a large PR.
+
+## Commits
+
+Subject form:
+
+```
+area: Imperative summary
+```
+
+- **Area** is a real package, directory, or subsystem token (`ci:`, `docs:`,
+  Go package name). Not a lone filename.
+- **Imperative** mood: Fix, Add, Remove — not "Fixed" or "This patch…".
+- No trailing period. Aim ≤ ~70–75 characters for the whole subject.
+- Not conventional-commits (`feat:` / `fix:` / `chore:` as types).
+
+Body explains **why**. Establish the problem, then say what you are doing.
+One logical change per commit; split fix and cleanup.
+
+## Pull requests
+
+Title matches the primary commit subject.
+
+- **What** changed
+- **Why** (problem and impact)
+- **Test** (concrete steps; "CI green" alone is weak)
+
+## Issues and closing
+
+Cite leftover issues by **full URL**. Gitea closes issues when `#N` appears in
+merge text, so do not put `#N` in the merge message unless that issue is actually
+done. Use `Fixes #N` / `Closes #N` only when the leftover work is finished.
+
+## License
+
+License TBD by owner.
+