diff --git a/README.md b/README.md
index 6ce4000..c8e77c5 100644
--- a/README.md
+++ b/README.md
@@ -169,3 +169,24 @@ git log --oneline -n 5
 git reset --hard <commit_sha>
 sudo systemctl restart runewager
 ```
+
+### Startup flow (prod-run.sh)
+
+```mermaid
+sequenceDiagram
+    participant Operator
+    participant Runner as prod-run.sh
+    participant System as OS/Filesystem/Systemd
+    participant NodeApp as node index.js
+
+    Operator->>Runner: Run prod-run.sh
+    Runner->>System: Validate runtime, dirs, deps, and .env
+    Runner->>System: Validate logrotate, cron fallback, and systemd config
+    alt Running under systemd
+        Runner->>NodeApp: exec node index.js (foreground)
+    else Running from shell/SSH
+        Runner->>System: Check existing bot process
+        Runner->>NodeApp: Launch with nohup in background
+    end
+    Runner->>System: Re-check process status after 15s
+```