System Messages Collection

systemmessages holds the site-wide banners that an admin posts for all logged-in users. One document is one message. web owns it; the schema is services/web/app/src/models/SystemMessage.mjs and the code is services/web/app/src/Features/SystemMessages/SystemMessageManager.mjs.

Fields

Field	Type	Meaning	Source
_id	ObjectId	Message id. The browser remembers by this id which messages the user closed (services/web/frontend/js/shared/components/system-message.tsx:10).	SystemMessage.mjs:5
content	String	Message text, default ''.	SystemMessage.mjs:7
__v	Number	Mongoose version key, added by message.save().	SystemMessageManager.mjs:29-30

Who Writes It

Code	What it does
SystemMessageManager.mjs:28-33 (createMessage)	POST /admin/messages (services/web/app/src/router.mjs:1150-1152, services/web/app/src/Features/ServerAdmin/AdminController.mjs:151-159): adds one message.
SystemMessageManager.mjs:22-26 (clearMessages)	POST /admin/messages/clear (router.mjs:1155-1157, AdminController.mjs:161-168): deletes all messages. There is no way to delete a single one.

Who Reads It

Code	What it does
SystemMessageManager.mjs:50-65	Each web process keeps all messages in memory and reloads them every 20 to 30 seconds, and right after its own create or clear.
services/web/app/src/Features/SystemMessages/SystemMessageController.mjs:6-24	GET /system/messages (router.mjs:331): returns the cached messages to logged-in users. While the site is closed (siteIsOpen false) it returns a fixed notice instead, which is not stored in Mongo.
AdminController.mjs:83-84	The /admin page lists the messages straight from Mongo.

Indexes

No migration creates an index on systemmessages; only the default _id index exists.

Notes

• With notifyOnSystemMessageChanges set, a create or clear is also published on the Redis channel refresh-system-messages, so other web processes reload at once (SystemMessageManager.mjs:9, :35-48, :75-87). Without it they pick up the change on their next timed reload.