MCP, plugins, skills, and hooks - Claude.ai Documentation

Claude Desktop on third-party (3P) supports the same extensibility model as standard Claude Desktop (MCP connectors, skills, and plugins), with the key difference that administrators provision them through managed configuration and the filesystem rather than the claude.ai admin console. There are three layers, in order of precedence:

Layer	Provisioned by	Delivered via
Managed MCP servers	Admin	`managedMcpServers` configuration key
Organization plugins	Admin	A plugin marketplace git repository (recommended) or a system-wide directory on each device
User extensions	End user	In-app Connectors and Plugins UI

Admins can disable the user layer entirely; see Controlling user extensions.

Managed MCP servers (admin)

Use the managedMcpServers configuration key to deploy MCP servers (remote HTTP/SSE or local stdio command) to every device. These appear in the user’s connector list automatically, can’t be removed by the user, and support per-tool policy locks (allow / ask / blocked). The Connectors & extensions section of the in-app configuration window provides a form for each server: name, per-tool policy, headers or a headers helper script, transport, and URL.

In-app configuration window showing a managed MCP server named sentry, with fields for name, tool policy, headers, headers helper script, Streamable HTTP transport, and URL. — A managed MCP server in the Connectors & extensions section of the in-app configuration window.

In the exported configuration, each server is one entry in the managedMcpServers array:

[
  {
    "name": "internal-search",
    "url": "https://mcp.example.corp",
    "oauth": true,
    "toolPolicy": { "search": "allow", "delete_document": "blocked" }
  },
  {
    "name": "ticketing",
    "url": "https://tickets.example.corp/mcp",
    "headersHelper": "/usr/local/bin/corp-sso-token",
    "headersHelperTtlSec": 900
  }
]

See the managedMcpServers schema in the configuration reference for every field, including static headers, OAuth, and the headers-helper executable for short-lived tokens. In the in-app configuration window, each server you add under Connectors & extensions has a Test this connection button that runs a live MCP initialize and tools/list against the server using the headers or OAuth settings you’ve entered, then shows the round-trip latency, the discovered tool list, or the error returned. Use it to validate reachability and credentials before exporting the configuration.

Short-lived credentials with a headers helper

For short-lived header credentials, configure the helper per server:

Key	Default	What it does
`headersHelper`	None	Executable that prints the request headers as a flat JSON object to stdout.
`headersHelperTtlSec`	300	Seconds the returned headers stay valid.
`headersHelperRefreshBufferSec`	60	Seconds before expiry that the helper re-runs. Set it above the helper’s typical runtime.

The helper follows the inferenceCredentialHelper execution model, with three differences: a 30-second time limit, no CLAUDE_HELPER_CONTEXT, and no prompting for input. The helper applies only to servers provisioned through managed configuration and never replaces the Authorization header on oauth entries. While the connection is open, only the TTL schedule triggers renewal; a failed request never re-runs the helper. A failed run does not interrupt the connection; Claude Desktop keeps the current headers and retries. A failure while the server is connecting shows the server as needing authentication.

Mid-session renewal requires Claude Desktop 1.21459.0 or later. Earlier versions run the helper only when the server connects.

Supported MCP servers

Any MCP server reachable from the user’s device over HTTPS works with Claude Desktop on 3P, including public servers from third parties and internal servers you build and host (including on internal gateways). The Claude connector directory is the canonical catalog of vetted servers. Every connector in the directory that is not labeled “Made by Anthropic” is accessible in Claude Desktop on 3P and can be deployed via managedMcpServers or installed by users. Connectors labeled “Made by Anthropic” are hosted on Anthropic infrastructure and are available only in standard Claude Desktop.

Productivity suites

Google Workspace and Microsoft 365 each have a dedicated setup path:

Google Workspace

Gmail, Calendar, Drive, Docs, and more via Google’s own Workspace MCP servers. See Google’s setup guide to get started.

Microsoft 365

Outlook, OneDrive, SharePoint, and Teams. Requires registering an app in your Entra tenant and an Anthropic allowlist step.

Plugin marketplaces (admin)

A plugin marketplace is a git repository that lists one or more Claude plugins. Claude Desktop clones the repository on each device, shows the plugins under Settings → Plugins → Organization, and keeps them in sync with the ref you pin. You control which plugins are available, which install automatically, and which are required. This is the recommended way to distribute organization plugins. Use the system-wide directory path instead when end-user devices cannot reach a git server.

Plugin marketplaces are in beta and require Claude Desktop 1.17377.1 or later.

The allowedPluginMarketplaces key configures the Cowork tab only. The Code tab reads Claude Code’s own plugin configuration on the host instead; to deploy a marketplace there, use Claude Code’s extraKnownMarketplaces and strictKnownMarketplaces settings. The same marketplace repository works for both tabs; only the configuration path differs.

Create the marketplace repository

A marketplace repository contains a .claude-plugin/marketplace.json file at its root that lists each plugin and its location. The format is shared with Claude Code; see Create and distribute a plugin marketplace for the full schema and walkthrough.

.claude-plugin/marketplace.json

{
  "name": "acme-internal",
  "owner": { "name": "Acme IT" },
  "plugins": [
    {
      "name": "expense-policy",
      "source": "./plugins/expense-policy",
      "description": "Answers questions about Acme travel and expense policy"
    }
  ]
}

Put plugin content directly in the marketplace repository with a relative source path. Plugins whose source points at a different repository are listed in the Organization tab but are not fetched or auto-installed. The marketplace name must match ^[A-Za-z0-9][A-Za-z0-9._-]{0,127}$ and must not be one of the reserved values unknown, org, or org-provisioned.

Configure the marketplace

You can add marketplaces directly in the in-app configuration window: in the Plugins & skills section, click Add marketplace and choose Blank, GitHub repo, or Git URL. The form validates the entry against the repository and exports the encoded JSON for you.

In-app configuration window Plugins & skills section showing the plugin marketplaces card with an open Add marketplace menu offering Blank, GitHub repo, and Git URL, above the organization plugins folder path with two loaded plugins. — The Plugins & skills section of the in-app configuration window, with the Add marketplace menu and the organization plugins folder.

To write the configuration by hand instead, add the repository to the allowedPluginMarketplaces configuration key. The key is read from an MDM profile, local configuration, or the bootstrap server response. In an MDM profile the value is a JSON array encoded as a string (see Value types); writing a native plist array instead of a string is the most common reason the Organization tab does not appear. In a local configuration file or the bootstrap response the value is a native JSON array.

.mobileconfig (macOS)

<key>allowedPluginMarketplaces</key>
<string>[{"source":"github","repo":"acme-corp/claude-plugins","ref":"a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0","credentialKind":"userGit","installationPreference":"auto_install"}]</string>

On Windows, write the same string to the allowedPluginMarketplaces value in the registry policy key your deployment already uses (HKLM\SOFTWARE\Policies\Claude for machine policy). Keep the value in the same hive as the rest of your configuration: when machine policy is present, the app ignores user policy entirely; see Deploy the configuration for the exact rule. For GitLab, Bitbucket, or a self-hosted git server, use "source": "git" with a full HTTPS url instead of repo.

Field	Description
`source`	Required. `"github"` (with `repo`) or `"git"` (with `url`).
`repo`	GitHub repository in `owner/name` format.
`url`	Full HTTPS clone URL. Use a bare URL with no embedded credentials; set `credentialKind` for authentication.
`ref`	Branch name, tag name, or full 40-character commit SHA. Required, and must be a full commit SHA, when `installationPreference` is `"auto_install"` or `"required"`.
`path`	Subdirectory containing `.claude-plugin/marketplace.json` when not at the repository root.
`expectedName`	If set, the clone is rejected unless the `name` in `marketplace.json` matches this value exactly, so a change to the manifest name cannot silently replace another configured marketplace.
`credentialKind`	`"anonymous"` (default), `"userGit"`, or `"credentialHelper"`. See Marketplace credentials.
`credentialHelper`	Path to an executable that prints an access token on stdout. Required, and only valid, when `credentialKind` is `"credentialHelper"`.
`installationPreference`	`"available"` (default), `"auto_install"`, or `"required"`. See Marketplace installation preferences.

You can configure multiple marketplaces; each appears as its own sub-tab under Settings → Plugins → Organization. If an admin-configured marketplace has the same repo, url, or manifest name as one the user added themselves, the admin entry replaces the user’s.

Marketplace installation preferences

`installationPreference`	Behavior
`"available"`	Plugins appear in the Organization tab for users to install manually. Nothing is installed automatically.
`"auto_install"`	Every plugin is installed automatically the first time the pinned `ref` is seen. Users can uninstall individual plugins; when you later change the `ref`, each plugin is installed again at the new revision.
`"required"`	Every plugin is installed automatically and re-asserted on every sync. Users cannot uninstall or disable required plugins.

"auto_install" and "required" marketplaces must pin ref to a full 40-character commit SHA. Claude Desktop refuses to auto-install from a branch or tag name so that the exact plugin content deployed to every device is deterministic and auditable.

Marketplace credentials

Claude Desktop clones marketplace repositories on the host operating system, outside the Cowork VM. The credential is used only for this clone and is never passed into the VM or exposed to the model.

`credentialKind`	How it authenticates
`"anonymous"`	No credential is sent. Use for public repositories.
`"userGit"`	Uses the git credential helpers already configured for the signed-in OS user (for example, `git-credential-manager`, macOS Keychain, or a GitHub CLI credential helper). Use when each user already has read access through their own account.
`"credentialHelper"`	Runs the executable at `credentialHelper` and uses its trimmed stdout as the HTTPS password with username `x-access-token`. Follows the same stdout contract as an inference credential helper.

Because the clone happens on the host, the repository does not need to be on the coworkEgressAllowedHosts allowlist. It does need to be reachable from end-user devices.

Roll out marketplace updates

To push a new plugin version to your fleet, commit the change to the marketplace repository, update the ref in allowedPluginMarketplaces to the new commit SHA, and distribute the updated managed configuration. Devices sync to the new revision on the next app launch or plugin settings refresh. To remove a marketplace, delete its entry; Claude Desktop unregisters it and uninstalls its plugins on the next sync.

Organization plugins (admin)

For most deployments, distribute organization plugins via a plugin marketplace instead. Marketplaces let you manage plugin content in git and roll out updates by changing a single configuration value, rather than pushing files to every device. Use the directory path below when end-user devices cannot reach a git server.

Plugins bundle MCP connectors, skills, slash commands, hooks, and sub-agents into a single directory. On this path, admins distribute plugins by placing them in a system-wide directory on each device, typically via the same MDM or software-distribution channel used for the app itself.

Plugin directory location

Platform	Path
macOS	`/Library/Application Support/Claude/org-plugins/`
Windows	`C:\Program Files\Claude\org-plugins\`

On Windows, the directory is under Program Files (not ProgramData) so that only administrators can create or modify it. Claude Desktop treats the presence of this directory as an admin-provisioned source.

Plugin structure

Each subdirectory of org-plugins/ is one plugin. The directory name is the plugin’s canonical name.

org-plugins/
└── code-reviewer/
    ├── .claude-plugin/
    │   └── plugin.json
    ├── version.json
    ├── .mcp.json
    ├── agents/
    │   └── code-reviewer.md
    ├── commands/
    │   └── find-all-bugs.md
    └── skills/
        └── security-review/
            └── SKILL.md

File	Purpose
`.claude-plugin/plugin.json`	Required. Plugin manifest (name, description, version). Directories without this file are ignored.
`version.json`	`{"version": "1.2.3"}`. When this string changes, Claude Desktop re-syncs the plugin on next launch. Any string change triggers re-sync (there’s no semver ordering, so a downgrade is just another version string). If absent, the directory’s modification time is used instead.
`.mcp.json`	MCP servers bundled with this plugin. A JSON object keyed by server name: `{"mcpServers": {"<name>": {"type": "http", "url": "...", "oauth": true}}}`. Each entry uses `type` (`http` or `sse`), not `transport`, and supports `url`, `headers`, and `oauth` only; `toolPolicy`, `headersHelper`, and `headersHelperTtlSec` are not read from this file.
`agents/`	Sub-agent definitions.
`commands/`	Slash-command definitions.
`skills/`	Skill directories.
`hooks/`	Hook definitions that run on agent lifecycle events.

See the plugins reference for the full file format of each component, including the hooks schema.

Symlinks inside a plugin are followed as long as the target resolves to a path inside the plugin directory. Symlinks that point outside the plugin (for example, skills/foo/SKILL.md → /etc/hosts) are skipped. A symlinked top-level plugin directory (for example, org-plugins/my-plugin → /opt/shared/my-plugin) is also followed.

MCP servers declared in a plugin’s .mcp.json don’t carry a toolPolicy field in the plugin file itself. To lock tools on a plugin-delivered server, set orgPluginSettings in managed configuration, keyed on the server’s name.

Auto-installing organization plugins

By default, organization plugins appear in the user’s plugin browser as available to install, and each user opts in. To install a plugin automatically for every user, set installationPreference in the plugin’s .claude-plugin/plugin.json:

{
  "name": "code-reviewer",
  "version": "1.0.0",
  "description": "Internal code review assistant",
  "installationPreference": "required"
}

Value	Behavior
`"required"`	Installs automatically when the user signs in. The Uninstall action is hidden. If the plugin is removed from disk, it reinstalls on the next sign-in.
`"auto_install"`	Installs automatically when the user signs in. Users can uninstall it, and it stays uninstalled for that user.
`"available"` (or omitted)	Default. Users install manually from the plugin browser.

This mirrors the installation preference behavior of remote-managed plugins on claude.ai. Changing a plugin’s installationPreference takes effect the next time each user signs in.

Updating organization plugins

To roll out a new version of a plugin:

Update the plugin contents in org-plugins/<name>/ via your software-distribution tool
Bump the version string in version.json
Users pick up the change on their next app launch

User extensions

Unless restricted by an admin, end users can add their own extensions through the in-app UI:

Plugins: install plugins (which can bundle skills, hooks, slash commands, and sub-agents) from the Plugins settings page
Connectors: install local desktop extensions (.mcpb) from the Connectors settings page
Local MCP servers: add local MCP server processes from Settings → Developer, when enabled by the admin

End users cannot add remote MCP servers; remote servers are available only via admin-provisioned managedMcpServers or organization plugins. User-added extensions are stored in the user’s local data directory and apply only to that device.

Controlling user extensions

Admins can restrict or disable each user-extension surface independently via managed configuration:

Key	Effect when `false`
`isLocalDevMcpEnabled`	Users cannot add their own local MCP servers from Settings → Developer.
`isDesktopExtensionEnabled`	Users cannot install local `.mcpb` desktop extensions.
`isDesktopExtensionSignatureRequired`	(When `true`) Unsigned `.mcpb` extensions are rejected.

Setting the first two to false restricts MCP servers and connectors to those delivered through managedMcpServers and org-plugins/. Users can still add their own skills and plugins regardless of these settings. See the Locked down profile for a complete example.

Code tab

How extensions and managed settings reach the embedded Claude Code engine.

MCP in Claude Code

Configure MCP servers for the standalone Claude Code CLI.

Claude Code plugins

Plugin structure, marketplaces, and management for Claude Code.

Managed MCP in Claude Code

Restrict which MCP servers Claude Code users can add.

​Managed MCP servers (admin)

​Short-lived credentials with a headers helper

​Supported MCP servers

​Productivity suites

Google Workspace

Microsoft 365

​Plugin marketplaces (admin)

​Create the marketplace repository

​Configure the marketplace

​Marketplace installation preferences

​Marketplace credentials

​Roll out marketplace updates

​Organization plugins (admin)

​Plugin directory location

​Plugin structure

​Auto-installing organization plugins

​Updating organization plugins

​User extensions

​Controlling user extensions

​Related topics

Code tab

MCP in Claude Code

Claude Code plugins

Managed MCP in Claude Code

Managed MCP servers (admin)

Short-lived credentials with a headers helper

Supported MCP servers

Productivity suites

Plugin marketplaces (admin)

Create the marketplace repository

Configure the marketplace

Marketplace installation preferences

Marketplace credentials

Roll out marketplace updates

Organization plugins (admin)

Plugin directory location

Plugin structure

Auto-installing organization plugins

Updating organization plugins

User extensions

Controlling user extensions

Related topics