# Fork Divergence Registry

This document tracks all functional differences from upstream.

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## D-0001: Authentication flow postnumber validation

Type: 
- Behavioral divergence

Upstream:
- MAS handles registration by allowing user to enter its own username

Fork:
- Added integration with an external postnumber microservice via HTTP RPC during account creation; utilizes Letro logic for data validation.

COMMIT_REFS:
- 12d0be9d7cbc837bfe1780e12d88f47e5bbd9fb6

Impact:
- Alters auth data validation pipelines
- Introduces external optional dependency (postnumber service)