How Federation Works
Federation separates the site lifecycle into three independent steps:
Build
Each parcel project generates a complete, standalone Reverb 2.0 site — chrome, navigation, search, and its own content groups. A parcel is fully testable on its own before it joins the shared site.
Deploy
Each project deploys only its role-appropriate slice into one shared output destination. Parcel projects deploy their content groups; the shell project deploys the site files (the chrome). The deploy scope you set on each target controls which slice is published. Each parcel's deployment also includes a small deployed record that identifies the parcel for the composition step.
Compose
An AutoMap composition job (.wacj) reads the deployed records already at the destination, assembles the combined site table of contents, splices it into the deployed shell, refreshes the site's sitemap.xml and url_maps.xml, and advances the browser cache key — without rebuilding any content. On an Amazon S3 destination it also uploads the recomposed files and issues a CloudFront invalidation.
Note: Federated parcel composition is a WebWorks Reverb 2.0 feature. Other output formats do not declare the capability, and their targets always deploy everything.