Reserve Matrix localparts and system names at identity creation #34
2026-11-10
Test the whole reserved set through both paths and pin case-insensitive matching
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Reserve Matrix localparts and system names at identity creation
The identity becomes the Matrix localpart at SSO, so a new account must not mint a name that a Matrix account already holds (the 13 Synapse localparts) or a system name. Native register refuses a reserved name; a derived identity takes the next free suffix. Lookups of existing accounts and existing rows are untouched; there is no exemption path. Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>