Hey everyone, Said here, the maker of CrewTower.
On October 1, Claude Code shipped mods. Hooks could already tell an outside app what Claude was doing and answer a permission prompt. They could never talk back. A mod can.
A mod is a small JavaScript or TypeScript file that Claude Code loads into its own process. It gets called on every event (a tool call, a prompt, a turn ending, part of the screen being drawn) and can watch it, rewrite it, or take it over. It can draw panes and buttons, add slash commands, read context numbers directly, and reach outside Claude Code.
That last part is what I needed. CrewTower lives in the MacBook notch and shows every agent session you run. With a small mod, each Claude card in the notch can now talk to its session: