Capabilities
Panels
Mount your own UI next to the selected item: an inspector in the info panel, or a viewer in the media area.
Inspectors and viewers
inspectors[] attaches to the info panel; viewers[] attaches to the media area. Both take the same shape, both need view.mount, and both receive the current selection through window.atlas.
"inspectors": [{
"id": "my-inspector",
"label": "My Inspector",
"entry": "inspector.html",
"mediaKinds": ["text"],
"extensions": [".myext"]
}]idRequired. Your identifier for the surface.entryRequired. Package-relative path to the HTML that renders it.labelOptional. Shown to the user.mediaKindsOptional. Only mount for these media kinds. Omit to mount for all of them.extensionsOptional. Only mount for these extensions, normalised to lowercase with a leading dot.view.mount becomes required as soon as inspectors, viewers, or itemActions is present — install fails without it.
Panel or window?
Use a panel when your feature is about the item the user is already looking at: extra details, a related strip, a set of controls. Use a window when your feature is its own workspace.