1 files changed, 8 insertions, 2 deletions
diff --git a/packages/meshbay-hub/src/meshbay_hub/api/users.py b/packages/meshbay-hub/src/meshbay_hub/api/users.py
index 05f58cd..9150909 100644
--- a/packages/meshbay-hub/src/meshbay_hub/api/users.py
+++ b/packages/meshbay-hub/src/meshbay_hub/api/users.py
@@ -78,6 +78,10 @@ async def _verify_captcha_or_raise(token: str | None, request: Request) -> None:
 
 # ── Models ────────────────────────────────────────────────────────────────────
 
+# Mirrored by USERNAME_MIN_LEN in static/auth-page.js; test_username_floor.py
+# holds the two equal.
+USERNAME_MIN_LEN = 8
+
 class RegisterRequest(BaseModel):
     username:        str
     email:           str
@@ -92,9 +96,11 @@ class RegisterRequest(BaseModel):
     @field_validator("username")
     @classmethod
     def username_valid(cls, v: str) -> str:
+        # Registration only. Login, reset and deletion take the name as stored,
+        # so accounts created under the older 3-character floor keep working.
         v = v.strip()
-        if len(v) < 3 or len(v) > 64:
-            raise ValueError("username must be 3-64 chars")
+        if len(v) < USERNAME_MIN_LEN or len(v) > 64:
+            raise ValueError(f"username must be {USERNAME_MIN_LEN}-64 chars")
         if not v.replace("_", "").replace("-", "").replace(".", "").isalnum():
             raise ValueError("username: only letters, digits, -, _, .")
         return v