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# DF8105: Devframe Already Mounted

## Message

> Devframe "`{name}`" (id "`{id}`") is already mounted on this hub

## Cause

`mountDevframe(ctx, def)` was called with a devframe whose `id` already belongs to another devframe mounted on the same hub. Devframes are deduplicated by `id`, and the definition's `duplicationStrategy` is `'warn'` (the default) or `'throw'`.

## Fix

Set `duplicationStrategy` on the definition to choose how duplicates are handled:

- `'warn'` (default) — keep the first registration, drop the later one, and emit this warning.
- `'silent'` — drop the later one without warning.
- `'throw'` — surface duplicates as a thrown error.
- `'duplicate'` — let every instance coexist under a disambiguated dock id (`my-tool`, `my-tool-2`, …).

Otherwise, remove the redundant `mountDevframe` call so each devframe is mounted once.

## Source

- [`packages/hub/src/node/mount-devframe.ts`](https://github.com/devframes/devframe/blob/main/packages/hub/src/node/mount-devframe.ts) — `mountDevframe()` emits this when a devframe sharing an already-mounted `id` is mounted and the strategy is not `'duplicate'`.
