Memory
Durable facts about you and your work, read into every seat's brief. "We use pnpm, not npm." "The staging database is read-only." Add, edit and delete them in Settings; there is a ceiling so it stays a set of facts rather than a diary, and anything that looks like a secret or personal data is refused rather than stored.
The desktop app also keeps memories per workspace, because what is true of one repository is rarely true of the next, and it can import what you have already told Claude Code.
Skills
A reusable block of instructions you invoke with /name. Your review checklist, your commit-message format, the way your team likes a migration written. It visibly wraps your message, so you can always see what was actually sent.
On the web and the phone a skill is stored on the account and can be shared with your team. On the desktop it is a file in .letthemchat/skills, so it lives in the repository with the code it is about, and one can be imported from a URL.
House rules
Three standing instructions — one for the lead, one for reviewers, one for a directed answer — that outrank each seat's built-in brief. This is where you change the room's manners rather than its knowledge: "reviewers, always run the type check", "never write a comment that restates the line below it".