Plugin Developer Mode (load unpacked plugins)

What it is

Developer Mode lets you build and run your own AMC plugins straight from a source folder on disk — the same "Load unpacked" model as Chrome extensions. No packaging, no checksums, no marketplace submission, no external CLI: pick the folder, and the plugin loads.

Where to find it

Settings → Plugins → Developer Mode — the Developer Mode section of that page, desktop only. It is a section inside the Plugins page rather than a page of its own, and none of its operations are reachable from a paired phone or from the CLI control server.

How it behaves

What you can do

• Turn on Developer Mode — a toggle with explicit trust wording: unpacked plugins skip the marketplace's distribution checks, and a plugin backend runs with full Node access, so only load folders whose code you trust. Turning the toggle OFF fully unloads every dev plugin (workers stopped) — it is the kill switch.
• Load unpacked plugin — a native folder picker. The folder must contain a valid manifest.json; if the manifest is invalid you see the exact validation error, verbatim. Loaded plugins appear with a DEV badge and outrank a marketplace or built-in copy of the same plugin id.
• Hot reload — AMC watches the folder. Saving a UI file reloads the plugin's webview instantly; changing manifest.json or the backend build output triggers a full disable→enable cycle automatically. node_modules and .git are ignored, and reload storms are debounced.
• Dev diagnostics — the plugin's Settings card shows its live backend status, the last error verbatim, and a recent log tail; the plugin's own panel gets a slim dev toolbar with Reload and Open DevTools.
• Reset storage — wipes the plugin's stored data (webview storage + its data folder) for a clean-slate test; your source folder is untouched.
• Remove — unregisters the folder. It NEVER deletes or modifies the folder on disk, and re-adding it later brings the plugin back.

Rules and safety (why some folders are refused)

• Folders inside AMC's own data directory, inside ~/.claude, your home folder itself, or a whole drive root cannot be registered; up to 20 folders.
• A registered folder that later breaks (deleted, or its manifest stops parsing) shows an error card with the verbatim reason instead of silently vanishing — Remove works on it by path.
• Developer Mode is desktop-only: none of its operations are reachable from a paired phone or the CLI control server (the existing POST /plugins/:id/reload route remains for the external amc-plugin CLI's own loop).
• The marketplace's distribution security (checksums, signatures, consent dialogs) is completely untouched — dev mode is a parallel path for your own code, not a relaxation of the store's checks.
• Uninstalling a marketplace plugin now also fully stops its background worker first, and if a shipped built-in baseline of the same plugin remains, the toast says so ("the built-in version remains").

For agents

• Origin precedence: dev > marketplace > builtin; the loader's dev scan pass runs only while pluginDevMode is on. Retired plugin ids stay barred from every source, including dev.
• The two backing settings (pluginDevMode, devPluginFolders) are INTERNAL_ONLY — writable only via the plugin:dev-* IPC handlers, never a generic settings PATCH.
• Channels: plugin:dev-set-mode / dev-add / dev-remove / dev-reload / dev-reset-storage / dev-get-logs (all WS-blocked), push plugin:dev-ui-reload.
• Contract: .claude/memory/contracts/plugin-dev-mode-contract.md (11 test-locked invariants — read it before changing any of this).

Related

Developer Mode is the parallel path to the Plugin Marketplace, which is where plugins are normally browsed, installed and removed — that is plugin-marketplace.md. Once a plugin of your own is loaded, the screen a user configures it on is plugin-settings-panel.md, and the wider set of capabilities a plugin's own screen may call is plugin-bridge-capabilities.md.