diff --git a/Dockerfile b/Dockerfile
new file mode 100644
index 0000000..24dc8f5
--- /dev/null
+++ b/Dockerfile
@@ -0,0 +1,8 @@
+FROM node:20-bookworm
+
+RUN useradd --create-home --shell /bin/bash --groups sudo ci
+RUN apt-get update && apt-get install -y jq sudo zstd
+RUN echo '%sudo ALL=(ALL) NOPASSWD:ALL' >> /etc/sudoers
+
+USER ci
+WORKDIR /home/ci
diff --git a/README.md b/README.md
index d1856b8..e06bd51 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,14 @@
-# actions-base-image
+# Forgejo actions base image
 
+Docker image with all dependencies installed, configured to be as close to
+GitHub actions as possible.
+
+Built and tagged on flora-6 with:
+
+```
+docker build --tag node:20-bookworm .
+```
+
+Uses a `ci` user with passwordless sudo to enable nix single-user install.
+
+See this [GH issue](https://github.com/NixOS/nix/issues/1559) for additional context.