Observables in xBuild

xBuild uses observable subscriptions internally for reactive config updates.

Why it matters

When configuration changes at runtime, active variant services are notified automatically.

This enables:

• hot reconfiguration without restart
• variant-level updates while watch/build is running
• controlled service re-init when required (for example tsconfig change)

Internal behavior (high level)

• Variant services subscribe to configuration state.
• A config change event triggers variant re-initialization logic.
• Build/lifecycle settings are refreshed from merged config.

For most users

You usually do not need to interact with observables directly.

Use:

• overwriteConfig for full replacement
• patchConfig for incremental changes

and xBuild handles propagation through its observable layer.