diff --git a/README.md b/README.md
index a7062ed..77e945e 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,50 @@
-# makepkg
+# `makepkg`-Action
+
+This action builds Arch packages. It is meant to be run inside an `archlinux`
+container, like the one we provide at
+[aur/runner-image](https://git.michaelsasser.org/aur/runner-image), which comes
+with all the necessary tools. Alternatively you could install the necessary
+tools yourself before running this action.
+
+## inputs
+
+| Name                      | Default  | Required | Description                                      |
+| ------------------------- | -------- | -------- | ------------------------------------------------ |
+| `update_package_database` | `'true'` | No       | Download fresh package databases before building |
+| `update_checksum`         | `'true'` | No       | Update the checksum before building the package  |
+| `lint_pkgbuild`           | `'true'` | No       | Run namecap on the PKGBUILD                      |
+| `install_package`         | `'true'` | No       | Install the package after it was built           |
+| `lint_package`            | `'true'` | No       | Run namecap on the resulting package             |
+
+## Example usage
+
+```yaml
+jobs:
+  build:
+    name: Build & Lint
+    runs-on: ubuntu-latest-amd64
+    container:
+      image: "git.michaelsasser.org/aur/runner-image:latest"
+      credentials:
+        username: ${{ vars.USERNAME_ACTIONS }}
+        password: ${{ secrets.PERSONAL_ACCESS_TOKEN_ACTIONS }}
+
+    steps:
+      - name: Checkout
+        uses: https://git.michaelsasser.org/actions/checkout@v4
+
+      - name: Build Package
+        uses: https://git.michaelsasser.org/actions/makepkg@main
+```
+
+## Semantic Versioning and Branching Model
+
+This action uses [SemVer](https://semver.org/) for its release cycle and
+follows the
+[GitHub Flow](https://docs.github.com/en/get-started/using-github/github-flow).
+
+## License
+
+Copyright &copy; 2020-2001 Michael Sasser <Info@MichaelSasser.org>. Released
+under the MIT license.
 
-Build Arch Packages
\ No newline at end of file
diff --git a/action.yml b/action.yml
new file mode 100644
index 0000000..f926d91
--- /dev/null
+++ b/action.yml
@@ -0,0 +1,77 @@
+---
+name: makepkg
+description: Build Arch Linux Packages.
+author: Michael Sasser <info@michaelsasser.org>
+
+branding:
+  icon: shield
+  color: blue
+
+inputs:
+  update_package_database:
+    description: Download fresh package databases before building.
+    required: false
+    default: "true"
+  update_checksum:
+    description: Update the checksum before building the package.
+    required: false
+    default: "true"
+  lint_pkgbuild:
+    description: Run namecap on the PKGBUILD.
+    required: false
+    default: "true"
+  install_package:
+    description: Install the package after it was built.
+    required: false
+    default: "true"
+  lint_package:
+    description: Run namecap on the resulting package.
+    required: false
+    default: "true"
+
+runs:
+  using: composite
+  steps:
+    - name: Update Package Database
+      if: inputs.update_package_database == 'true'
+      shell: bash
+      run: |
+        pacman --version
+        sudo pacman -Sy --noconfirm
+
+    - name: Update checksums
+      if: inputs.update_checksum == 'true'
+      shell: bash
+      run: |
+        updpkgsums --version
+        updpkgsums
+
+    - name: Download & Extract Packages
+      shell: bash
+      run: |
+        cat PKGBUILD
+        makepkg --version
+        makepkg -so --noconfirm --needed
+        ls -la src/
+
+    - name: Lint PKGBUILD
+      shell: bash
+      if: inputs.lint_pkgbuild == 'true'
+      run: |
+        namcap --version
+        namcap PKGBUILD
+
+    - name: Build
+      shell: bash
+      run: |
+        if [ ${{ inputs.install_package }} = 'true' ]; then
+          makepkg -si --skipchecksums --skippgpcheck --noconfirm --needed
+        else
+          makepkg -s --skipchecksums --skippgpcheck --noconfirm --needed
+        fi
+        ls -la
+
+    - name: Lint Package(s)
+      if: inputs.lint_package == 'true'
+      shell: bash
+      run: namcap *.pkg.tar.zst