Plugins package skills and optional MCP servers together to extend ChatGPT.app. Coskey owns the
local marketplace: it validates packages, tracks versions, checks the remote index and places the
selected version under ~/.coskey/plugins/marketplace. Installation, enabling and upgrades still
happen on the Plugins page in ChatGPT.app.
Choose your path
| Guide | Best for |
|---|---|
| Import a local plugin | You already have a .zip package and want to add it to the local marketplace |
| Remote plugins | A plugin is published to Coskey’s remote index and you want to check, download or update it |
| Coskey Tools | Using Coskey’s built-in status, model, session and diagnostics tools |
Shared workflow
- Prepare a local version under Coskey → Plugins. It may be built in, locally imported or downloaded from the remote index.
- Select Open ChatGPT.app, then open Plugins → Coskey plugin marketplace.
- Install or enable the plugin; reinstall the new version when upgrading.
- Return to Coskey, refresh, and verify the app cache version and enabled state.
Downloading or importing in Coskey does not make a plugin available yet. ChatGPT.app always performs the actual installation and enablement; Coskey never writes the app’s plugin cache directly.
Sources and status
| Source | Card tag | Meaning |
|---|---|---|
| Built in | — | Ships with Coskey; currently Coskey Tools |
| Remote | Remote | Comes from Coskey’s plugin index and enters the local marketplace after download |
| Local | Local | Imported from a local ZIP; refreshing the marketplace keeps it |
Plugin cards also show the version and app-side states such as Not installed, Installed but not enabled and Installed and enabled. These are status labels; installation still happens in ChatGPT.app.
Security boundary
- A package may contain only skills, or also a local MCP server that runs commands on this machine.
- Coskey validates the ZIP structure, paths, size and the remote manifest’s SHA-256, but that is not a code audit.
- Install only trusted sources and review the skills, MCP server and developer information in ChatGPT.app before enabling it.
- Write actions such as switching models or adopting sessions should explain their impact and wait for confirmation.