diff --git a/docs/drone-ci.md b/docs/drone-ci.md
new file mode 100644
index 00000000..088a777f
--- /dev/null
+++ b/docs/drone-ci.md
@@ -0,0 +1,19 @@
+# Drone CI
+
+We currently use two CI systems, [drone CI](https://drone.io), reachable via
+https://ci.pub.solar and [Forgejo Actions](https://forgejo.org/docs/latest/user/actions/),
+which UI is integrated into https://git.pub.solar, for example
+https://git.pub.solar/pub-solar/infra/actions.
+
+### Signing the `.drone.yml` file
+
+Login to https://ci.pub.solar by clicking on the user icon in the bottom left.
+After logging in, you can view your personal API token by clicking on the same
+icon. If you're using the nix [development-shell](./development-shell.md), the
+`drone` command will already be installed.
+
+```
+export DRONE_TOKEN=<your-drone-api-token>
+
+drone --token $DRONE_TOKEN sign --save pub-solar/os
+```