Grok Bot plugins and MCP: install, authorize, and run custom servers

Plugins (the docs also call them connectors) give a Bot a structured line into Gmail, Slack, Notion, Linear and other services, so it calls tools instead of clicking around websites. Install one from Connect Apps in the sidebar, finish the sign-in in your browser, and every Bot on your account can use it. Custom MCP servers work too, but only if they are reachable over public HTTPS.

This guide reflects the docs, Cursor's help pages and the changelog through 0.78.1 (October 27), plus attributed Cursor staff forum replies we have not reproduced. We have not tested any connector.

At a glance#

Not sure whether a plugin or the browser fits? Our connectors vs browser guide walks through the decision.

Three renames in one week: Marketplace became Connect Apps#

If older tutorials send you hunting for Marketplace, here is the timeline from the changelog:

• 0.60.0 (September 26): the sidebar's Marketplace button became Connect apps.
• 0.63.0 (September 29): Marketplace stopped listing Bots and searched only plugins.
• 0.67.0 (October 2): Marketplace became Connect Apps, with category chips and "Recommended for you" on top.

Bot templates moved to the web; see our templates and marketplace guide. Open Connect Apps from the bottom of the sidebar or press Cmd+Shift+M; the docs' shortcut list also gives Cmd/Ctrl+Shift+W. Some docs.x.ai pages still said Marketplace as of October 11.

Since 0.75.2, Connect Apps shows each plugin's own logo, waits longer instead of showing "Couldn't refresh," and no longer offers a broken Uninstall on built-in plugins.

GitHub is built in now#

Staff said on September 28 that GitHub runs through your connected Cursor GitHub account, replacing the old marketplace plugin. Since 0.71.2, if GitHub cannot see a repository the Bot stops retrying and links the page where you grant access. Since 0.75.2, the connector can list repositories, compare commits, list a pull request's commits, and read branch and issue comments.

How to install and authorize a plugin#

On mobile, tap your avatar at the top left and choose Connect apps. On desktop:

1. Open Connect Apps in the sidebar, or tap a Connect card in chat.
2. Add the plugin. Since 0.63.0, plugins that need sign-in (Gmail, for one) start it immediately.
3. Finish the provider's sign-in within about 10 minutes. If it stalls, choose Reconnect on the plugin or Reopen on the chat card; if the card says it failed, choose Retry. Since 0.77.0 (October 26), sign-ins started from a card can finish up to an hour later.
4. Confirm it shows as authorized under Installed. If it says Needs auth or Disconnected, choose Authenticate (Authorize on phone).
5. Attach it to a task by typing @ in chat. To disable individual tools, open Your plugins → Manage plugins and skills.

Plugin-specific quirks#

• Glean asks for your Glean MCP URL first; get it from your Glean admin.
• Zoho CRM (0.75.2) makes you pick your regional data center before sign-in.
• Salesforce and other multi-server plugins show one row per server since 0.75.5. Sign in to every row.
• Your own OAuth client: since 0.75.2, setup lists the callback URLs. Register exactly those with the provider before signing in.
• QuickBooks Online became available to connect in the October 11 entry (0.69.0 to 0.70.2).
• Figma, Notion, Canva and other app-backed connectors can render interactive cards in chat.

Shortcuts worth knowing: handing a Bot a connector link installs the matching catalog plugin when one exists. Since 0.75.8 (October 24), a plugin a Bot installs mid-task is usable in that same task.

Where tokens live and who can use them#

The docs say OAuth tokens stay on Cursor's connector backend. Bots call tools without receiving tokens, and tokens never land on the Bot's computer. That makes a plugin sturdier than a browser login, which depends on cookies on the shared computer.

A plugin can do only what the connected account already can. The Slack plugin posts as the Slack user you connected, and only where that user can post. It cannot raise access or change sharing.

Every Bot on your account can use every connected account. On a Cursor team, the connector policy decides which plugins members get; blocked ones show "Disabled by team admin." The MCP allowlist is Enterprise only. Blocking a plugin does not block the service's website.

Other limits and exceptions:

• Skill ceiling: since 0.71.2 (October 14) a Bot can use up to 200 skills from installed plugins, up from 24.
• Public X content needs no plugin. Add the X plugin only for DMs, bookmarks, home timeline or who liked your posts. Since 0.75.5, asking about your X account connects X through your linked account even if you removed the plugin, and connecting X also connects X Money.
• Tool toggles since 0.75.2 apply the state you saw, so a stale list cannot re-enable a blocked tool.

Adding a custom MCP server#

There is no settings form. Per a Cursor staff reply on August 30, you ask the Bot in chat to add the server, and it must be a public HTTPS URL using streamable HTTP or SSE. OAuth discovery runs from Cursor's infrastructure, so anything behind a VPN or on localhost fails (staff, August 12). Connectors authenticate only through OAuth; there is no safe way to send a secret header (staff, September 17).

Servers on your own laptop are never attached, over stdio or localhost (staff, August 13). Command-style servers can run on the Bot's cloud computer instead: staff suggested registering them as npx or uvx commands or keeping wrapper scripts there (September 8). To re-point a custom stdio server, add it again under the same name (September 28).

The Shared Bots docs warn that teammates can read a command server's command and arguments. Never put a credential in either. Since 0.77.0, a custom server using a private certificate authority works once you approve that authority.

Copy-paste brief#

Add a custom MCP server named [name] at [https URL] using

[streamable HTTP | SSE].

Do not paste any key or token into this chat. If the server needs

credentials, start its OAuth sign-in or ask me for a secure secret.

Once connected, list every tool it exposes, then run ONE read-only

call on [harmless test input].

Do not call any tool that creates, changes or deletes data.

Troubleshooting: open and recently fixed issues#

Status as of October 28. Forum threads on custom MCP OAuth, MCP-Protocol-Version, outbound traffic and Vercel were rechecked October 25; other forum items date from October 11.

Still open#

• Custom MCP OAuth fails with redirect_uri not allowed → registration sends a cursor:// callback that https-only providers reject. For Cloudflare Access, staff confirmed on October 19 that adding cursor://anysphere.cursor-mcp/oauth/callback to allowed redirect URIs via the Access Applications API works. Home Assistant and other https/loopback-only providers still fail; no workaround as of October 21.
• Remote MCP server works, then returns empty HTTP 400 → Grok Bot omits the MCP-Protocol-Version header on reused sessions. Staff confirmed and flagged a fix (October 8). Reconnecting does not help.
• Stdio server or script cannot reach a database, mail or SSH port → since about October 1, some Bot computers allow outbound traffic only over HTTPS on port 443. Staff called it unintended and tracked (October 2); users still reported it October 22.
• Zoom error 4700 (Invalid redirect) → known issue, no workaround.
• SharePoint AADSTS50011 on Application-level permissions → connect with Delegated permissions from the dashboard's Integrations page.
• Vercel plugin "redirect URL is invalid" → cause identified September 21; no fix confirmed in the thread.

Fixed recently#

• Sign-in timed out after a few minutes → 0.77.0: up to an hour; a refused sign-in returns with the reason.
• Google apps asked to reconnect while merely throttled → 0.77.0: they stay connected and the Bot says try later.
• Background work kept calling a signed-out connector → 0.77.0: it stops and asks you to reconnect.
• Internal IDs instead of app names; "sign-in did not finish" while still signing in → 0.78.1: names shown; after 10 minutes the card asks "Still signing in?"
• Remove from Slack left Slack connected → 0.78.1 fixed it.
• New connector tools missing until reconnect; stale "Connected" state; garbled images → 0.75.8 fixed all three.
• Connector calls timed out after one minute → 0.71.2: two minutes, longer with progress.
• Plugin connected but "MCP server not found" → server-side fix rolled out September 28.
• Old GitHub plugin stuck with 0 tools → GitHub is built in; staff removed leftovers on request.

Plugins inside templates and Shared Bots#

Templates list their first-party plugins, but each new owner reinstalls and authenticates them. xAI's September 8 template guide says templates do not carry MCP servers, custom code or scripts.

On a Shared Bot, a sign-in plugin uses the account of whoever is chatting, a key-based plugin uses the Bot's own credential for everyone, and a custom remote HTTPS server can do either. Since 0.77.0, linked teammates use their own connectors and memory. Details live in our Shared Bots guide; Gmail specifics in the Gmail and Workspace guide; the security model in Is Grok Bot safe?.

Our take#

Reach for a catalog plugin first, and treat custom MCP as a power-user path that still has rough OAuth edges. Before any custom server touches real data, run the read-only brief above and confirm the tool list. Audit connected accounts regularly: every one of them is open to every Bot you own.

Frequently asked questions#

Where did Marketplace go in Grok Bot?#

It was renamed in stages. The sidebar button became Connect apps in 0.60.0 on September 26, Marketplace dropped Bots and listed only plugins in 0.63.0 on September 29, and it became Connect Apps in 0.67.0 on October 2. Bot templates moved to the web Marketplace. Open it from the bottom of the sidebar or press Cmd+Shift+M; the docs also list Cmd/Ctrl+Shift+W.

Can Grok Bot use an MCP server running on my laptop?#

No. A Cursor staff member said on August 13 that Grok Bot does not attach MCP servers running on your own machine, whether over stdio or on localhost, because Bots work on a cloud computer. Use a public HTTPS server, a catalog plugin, or the Bot's browser. Staff have since described running command-style servers on the Bot's cloud computer instead.

Does the Bot see my OAuth tokens?#

No, according to the official docs. OAuth tokens stay on Cursor's connector backend, Bots invoke tools without receiving them, and tokens are never stored on the Bot's computer. A plugin can only do what the connected account can already do in that service, so it cannot raise your access or change sharing settings.

Can I connect two accounts for the same service?#

For some plugins. Notion and some others support Add Another Account. Since 0.77.0 on October 26, adding a second Gmail or Google Drive account opens Google's account picker, and removing one leaves the others in place. Every Bot on your account can use every connected account, so disconnect any account a Bot should not touch.

Do Grok Bot templates include plugins and MCP servers?#

Templates list their first-party plugins, but each new owner must reinstall and authenticate them. xAI's September 8 template guide says templates do not carry MCP servers, custom code or scripts. For complex setups, it suggests having the Bot write setup instructions into the template so the next owner can repeat them.