diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
new file mode 100644
index 0000000..aba199f
--- /dev/null
+++ b/CONTRIBUTING.md
@@ -0,0 +1,34 @@
+# Contributing to OpenSquawk
+
+Bug reports, documentation improvements, and code contributions are welcome.
+Please open an issue before starting a large change so that its scope can be
+agreed in advance.
+
+## Contribution terms
+
+By intentionally submitting a pull request, patch, or other contribution for
+inclusion in OpenSquawk, you agree to the contribution grant in section 6 of
+the [OpenSquawk Community Source License](./LICENSE). In summary, you retain
+ownership of your contribution and grant the OpenSquawk copyright holders the
+rights needed to use, modify, distribute, sublicense, and relicense it,
+including in commercial offerings.
+
+Only submit material that you have the legal right to contribute. If your
+employer or another organization may own the material, obtain its written
+permission before submitting it. Do not submit a contribution if you do not
+agree to the contribution terms.
+
+## Development
+
+OpenSquawk uses Node.js 22 and Yarn 4. Install dependencies and run the checks
+relevant to your change:
+
+```bash
+corepack enable
+yarn install
+yarn test
+yarn typecheck
+```
+
+Keep pull requests focused, explain user-visible behavior changes, and include
+tests when practical.
diff --git a/README.md b/README.md
index 295ff5b..2b0d75f 100644
--- a/README.md
+++ b/README.md
@@ -67,5 +67,14 @@ when `TELEMETRY_URL` is empty.
 
 ## License
 
-OpenSquawk is licensed under the
-[OpenSquawk Community Source License 1.0](./LICENSE).
+OpenSquawk is source-available for personal self-hosting. Individuals may use
+and modify it privately, and may share source code and public forks under the
+same license. A running instance may only be used by the individual who hosts
+it. Providing functionality to anyone else is prohibited, whether paid or
+free of charge; this includes SaaS, shared instances, and hosting for clubs or
+other organizations. Commercial and organizational use requires an express
+written exception or separate license from the applicable copyright holder.
+
+Contributions are welcome under the contribution grant in section 6 of the
+[OpenSquawk Community Source License](./LICENSE). OpenSquawk is not open-source
+software as defined by the Open Source Initiative.