buildpack when the project follows the Cloud Native Buildpacks model. Pin both packImage and builder to digests, select a source context, and use project.toml only when project-specific buildpack settings are needed.
Example manifest
This is the validated example from the Towbarexamples/platform-modes project. Replace the documentation IP and project paths with values for your environment. builder must be one of Towbar’s reviewed Paketo or Heroku digests; an arbitrary digest-pinned builder will fail validation.
.towbar/apps/buildpack.app.yml
Configure it
The example uses an amd64 builder, a bounded context, and a workload cache. Keep the approvedbuilder digest or choose another from the app schema. packImage is a separate, digest-pinned pack CLI image. Validate the resulting image’s process and health behavior before adding public routing.
Buildpacks reject build secrets. If the build needs credentials, use a Dockerfile and a protected BuildKit secret mount instead.
Map the named environment to a branch, register and prepare its server, then sync the repository. Start with a manual deployment and verify the running service before opting into automation. See Application manifest for shared fields and Deployment modes to compare modes.