Tools beside your agents.
The toolbox is a column next to a project's sessions in the Grenade Mac app. Open your dev server in a browser, or a canvas for the agent to design on, and work with the agent on what it makes, in one window.
One tab each, as many as you need.
How the toolbox works.
Beside the panes
The toolbox is a column right of a project's sessions. The toolbox button at the sessions' right end shows or hides it and keeps its tabs (so does Show / Hide Toolbox in the menu, with no key until you give it one in Settings › Keyboard); drag its edge to make it wider.
Tabs, in any number
Open a browser or a canvas from the window's + menu or the + on the tab strip. ⌃⇥ steps through them, ⌘W closes the one in front.
In the sidebar too
Each tab is a row under its project's sessions, so a page or a canvas is one click away from the agent working on it.
Move it to another project
Drag a tab's row onto another project in the sidebar, or right-click it for Move to Group. Hold ⌥ to copy a canvas.
Full screen
Give a tool the whole window. The selected session's field floats at the foot, so you can keep talking to the agent.
Mac app only
The toolbox is part of the Mac app. Your sessions run the same either way, and the phone apps still show them.