diff --git a/.env.example b/.env.example
index 61ff8ca..955f27c 100644
--- a/.env.example
+++ b/.env.example
@@ -55,6 +55,8 @@ CLOAK_KEY3=
 # (secret) IRC_SERVER_KEY: shared with obbyircd, openssl rand -hex 32
 JWT_SECRET=
 IRC_SERVER_KEY=
+# obbyircd sends web push through obby-api at https://${API_FQDN} with IRC_SERVER_KEY.
+# WEBPUSH_BACKEND_URL=
 
 # --- voice / TURN ---
 # Default: obby-api runs an embedded pion/turn on TURN_PORT, signed
diff --git a/compose.yaml b/compose.yaml
index 4377aff..b6f49a2 100644
--- a/compose.yaml
+++ b/compose.yaml
@@ -35,6 +35,8 @@ services:
       VOICE_TURN_TTL: ${VOICE_TURN_TTL:-}
       INVITE_PAGE_PORT: "${INVITE_PAGE_PORT:-8661}"
       INVITE_BASE_URL: ${INVITE_BASE_URL:-}
+      WEBPUSH_BACKEND_URL: ${WEBPUSH_BACKEND_URL:-https://${API_FQDN}}
+      WEBPUSH_BACKEND_KEY: ${IRC_SERVER_KEY}
     env_file:
       - path: .env
         required: false