This is the backend for the default Backstage software templates. This provides the API for the frontend scaffolder plugin, as well as the built-in template actions, tasks and stages.

This @backstage/plugin-scaffolder-backend package comes installed by default in any Backstage application created with npx @backstage/create-app, so installation is not usually required.

To check if you already have the package, look under packages/backend/package.json, in the dependencies block, for @backstage/plugin-scaffolder-backend. The instructions below walk through restoring the plugin, if you previously removed it.

# From your Backstage root directory
yarn --cwd packages/backend add @backstage/plugin-scaffolder-backend

Then add the plugin to your backend, typically in packages/backend/src/index.ts:

const backend = createBackend();
// ...
backend.add(import('@backstage/plugin-scaffolder-backend/alpha'));

In the old backend system there's a bit more wiring required. You'll need to create a file called packages/backend/src/plugins/scaffolder.ts with contents matching scaffolder.ts in the create-app template.

With the scaffolder.ts router setup in place, add the router to packages/backend/src/index.ts:

+import scaffolder from './plugins/scaffolder';

async function main() {
  ...
  const createEnv = makeCreateEnv(config);

  const catalogEnv = useHotMemoize(module, () => createEnv('catalog'));
+  const scaffolderEnv = useHotMemoize(module, () => createEnv('scaffolder'));

  const apiRouter = Router();
+  apiRouter.use('/scaffolder', await scaffolder(scaffolderEnv));
  ...
  apiRouter.use(notFoundHandler());

At this point the scaffolder backend is installed in your backend package, but you will not have any templates available to use. These need to be added to the software catalog.

To get up and running and try out some templates quickly, you can or copy the catalog locations from the create-app template.