diff --git a/DEPLOY.md b/DEPLOY.md
index e1111e5..c372554 100644
--- a/DEPLOY.md
+++ b/DEPLOY.md
@@ -5,7 +5,15 @@ codes with amount entry, no catalog. Takings settle into the one platform
 UserWallet (5% fee), then withdraw via `account.ladill.com`.
 
 Public scans stay at `ladill.com/q/<code>` (blueprint decision — printed codes
-never migrate). During cutover, nginx can proxy payment-type codes to this app.
+never migrate). The platform host forwards payment codes to this app (see
+`MiniQrForwarder` on the monolith); grant the platform DB user read access:
+
+```bash
+sudo mysql -e "GRANT SELECT ON ladill_mini.qr_codes TO 'ladilldb'@'127.0.0.1'; FLUSH PRIVILEGES;"
+```
+
+Set `MINI_DB_*` on the platform `.env` if the lookup user differs from the
+main app DB user.
 
 ---