# How to add a custom connector to Meta Muse > Muse adds custom connectors from its chat. How to add a remote MCP server to Muse, approve the sign-in, and check that its tools work. Updated 2026-10-10 · https://upsy.ai/guides/muse/custom-connector ## Short answer Muse has no settings form for custom connectors. You ask for one in a chat, give Muse the server's address, and approve the sign-in it shows you. For Upsy, that's one message to paste and one sign-in, and it takes a few minutes on any Muse plan. ## How custom connectors work in Muse Muse has two kinds of connectors: - **Built-in connectors**, like Gmail, Slack and Notion, added in **Settings › Connectors** or by asking ("Connect my Gmail"). See the [Muse hub](/guides/muse). - **Custom connectors**, for anything else. [Meta's help page](https://www.meta.com/help/artificial-intelligence/1687253048996149/) says you ask Muse in a chat to create one, and Muse guides you through it. Any keys go into Muse's Secure Credentials Store, not the chat. Meta's help doesn't name MCP, but a remote MCP server (a connector that lets the assistant use another app) works as a custom connector. Muse reaches it from Meta's cloud, so it needs a public HTTPS address, not one on your own computer. **Meta doesn't review custom connectors** or how they use your data. Check who runs one, what it can do, and whether you can see what it did. ### Why the sign-in can fail partway Muse's cloud computer sends its internet traffic through a gatekeeper that Meta calls Sentinel, described in [Meta's security post](https://research.meta.ai/blog/security-and-safety-for-ai-agents-our-approach-with-muse). Muse can add an MCP server in two ways: 1. **With its built-in connector feature.** Meta's servers run the sign-in. This works with OAuth servers like Upsy. 2. **By writing the connection itself**, on its own cloud computer. For an OAuth server, the last step of the sign-in, where your approval is traded for an access token, can be blocked. If it does get through, the token refreshes later can still fail. That's why Upsy's setup prompt asks Muse for its built-in feature first. ## What you need - **A Muse account,** on any plan: Meta lists no connector limits for Free, Power or Maximum. - **The Muse app or muse.ai** for the setup, so you can open the sign-in link. - **A free Upsy account**, with the apps you want Muse to use already connected. - **No API key.** Upsy signs in with OAuth. ## Add Upsy to Muse 1. Go to [upsy.ai](https://upsy.ai), click **Set up Upsy** and sign up free. 2. Under **Apps**, click **Connect an app** and connect your apps, such as Gmail, Google Calendar or Slack. Each one opens that app's own sign-in. 3. Under **Assistants**, click **Add assistant**. Under **Which assistant?**, pick **Muse**. Upsy shows "Paste this into Muse" and a **Copy prompt** button. 4. Open a new chat in Muse and paste the prompt. It gives Muse Upsy's address, says there's no API key, and asks Muse to use its built-in connector feature. 5. Muse adds Upsy and shows a sign-in link or button. Open it. 6. An Upsy page asks to let Muse in. Sign in. Every connected app is ticked, and next to each you choose full access or read-only. Untick what Muse shouldn't use and click **Allow**. 7. Back in Muse, it lists Upsy's tools. Upsy's page switches from "Waiting for Muse to connect…" to "Muse is in", with what Muse can use. 8. Let Muse save the memory line (Upsy also shows it under **Help Muse remember**). Later chats don't see the setup message, so without it Muse uses Upsy only when you name it. This is the prompt; copy the current one from Upsy's page: ``` Add Upsy as a remote MCP server so you can use my memory, files, browser and connected apps. - Name: Upsy - URL: https://upsy.ai/connect (Streamable HTTP) - Sign-in: OAuth 2.1 with PKCE, no API key. Dynamic client registration is supported; the server metadata is at https://upsy.ai/.well-known/oauth-authorization-server. Add it through your built-in connector feature if you have one, so the sign-in runs on your servers; otherwise add it yourself. Once it's added, start the OAuth sign-in right away and show me the link or button to approve it. If you can't start it yourself, tell me exactly where to click. If the sign-in fails partway, for example a blocked token exchange, try the other way of adding it before giving up. After I approve, list Upsy's tools to confirm it works. Then, if you have memory, save this, filled in from the tools you got: "Upsy has my . Use it for these even when I don't mention Upsy, and prefer it over other connectors for the same thing." ``` To add it by hand instead, ask Muse in a chat to add a custom connector named Upsy at `https://upsy.ai/connect`. ## Check that it works Send Muse this: > Use Upsy to tell me which apps you can reach and what you're allowed to do in each. Muse should list each connected account, like your Gmail address, and what it may do there. Then try "Use Upsy to find my last email from my bank" and open **History** in Upsy: the search is there, under Muse. ## What Muse can do through Upsy - **Gmail:** search, read, draft, send and organize email ([Gmail with Muse](/guides/muse/gmail)). - **Google Calendar:** events, invitations and free time. - **Google Drive, Docs and Sheets:** search, read and save files, suggest changes to Docs, and update Sheets. - **Slack:** read channels and threads, find people, and send messages as you. - **Apps through their own MCP servers**, like Jira, ClickUp, Airtable and Fireflies. - **Memory, files and the cloud browser.** For each app, Muse gets **Full access**, **Read-only**, **Pick actions** (only the actions you choose, on Muse's page in Upsy) or **No access**. ## Prompts to try - "Use Upsy to show what's on my calendar tomorrow and find a free hour for a call." - "Search my email for the Airbnb confirmation for next month and add the check-in time to my calendar." - "What did the team decide in #launch this week? Use Upsy." - "Using Upsy, list my open Jira issues and sort them by due date." ## Troubleshooting ### The sign-in fails after you approve Muse may say the token exchange was blocked, or the sign-in didn't finish. The prompt tells Muse to try the other way by itself. If it still fails, ask Muse to remove the Upsy connector it made and add it again with its built-in connector feature, or paste the prompt into a new chat. Muse showing up on Upsy's Assistants page only means you clicked Allow; the real test is whether Muse can list Upsy's tools. ### Upsy works, then stops after about 15 minutes Upsy's access tokens last 15 minutes before Muse refreshes them. If Muse added Upsy by itself, the refresh can be blocked like the sign-in. Remove the connector and add it again through Muse's built-in connector feature. ### Muse asks for an API key Upsy has none. Tell Muse that Upsy signs in with OAuth and supports dynamic client registration, as the prompt says. ### Muse asks to allow access to upsy.ai Depending on your **Settings › Permissions**, Muse asks before it reaches a site it doesn't know. Allow it, or Muse can't reach Upsy. ### Muse only uses Upsy when you name it Save the memory line from step 8. Until then, say "use Upsy" in your request. ### An app you just connected doesn't show up Muse keeps the tool list it got when the chat started. Start a new chat. In the same chat, Upsy also offers newly connected apps through its `app_tools` and `app_call` tools. ## Security and privacy - **Muse never gets your passwords or app tokens.** It calls Upsy's tools, and Upsy calls the app. Every tool, and whether it reads or writes, is public at [upsy.ai/docs](https://upsy.ai/docs). - **Upsy enforces your access.** A tool you didn't allow isn't listed to Muse and can't be called. - **History** shows every action Muse takes through Upsy. **Alerts** email you when Muse sends 20+ messages, deletes 50+ items or reads from your apps 100+ times within 10 minutes, and when a new assistant or app is connected. - **Upsy has no approval step of its own.** Muse's [Permissions settings](https://www.meta.com/help/artificial-intelligence/1385290430137537/) decide when Muse asks you first, and Meta doesn't say how they apply to custom connectors. For a hard limit, use Read-only or Pick actions in Upsy. - **To turn it off,** flip Muse's switch on Upsy's Assistants page; it takes effect right away. **Remove** on Muse's page takes its access away for good, and its history stays. ## FAQ ### Does Meta Muse support MCP? Yes, through custom connectors. Meta's help describes custom connectors without naming MCP, but Muse can add a remote MCP server at a public HTTPS address when you ask in a chat. ### How do I add MCP to Muse? Ask Muse in a chat to add a custom connector, with the server's name, address and sign-in method, then approve the sign-in it shows. For Upsy, paste the setup prompt from Upsy's Assistants page. ### Does Meta review custom connectors? No. Meta says it doesn't review custom connectors or how they use your information, so add only ones you trust and can audit. ### Do custom connectors cost extra in Muse? Meta lists no separate price or plan limit for custom connectors. Upsy is free for personal use. ### Where do I remove a custom connector in Muse? Meta's help points to Settings › Connectors for disconnecting; if Upsy isn't listed there, ask Muse in a chat to remove it. To cut Upsy off right away, turn Muse off on Upsy's Assistants page. --- Upsy connects personal AI assistants (Muse, Grok, ChatGPT, Claude, Cursor, Claude Code, Codex, Devin) to your Gmail, Google Calendar, Google Drive, Slack, Notion and other apps through one MCP server, with a shared memory, files and a cloud browser signed in to your sites. You choose what each assistant may do in each app, see everything it did, and turn it off in one click. Upsy is free. To add Upsy to an assistant, add a remote MCP server (Streamable HTTP) named Upsy at https://upsy.ai/connect. It signs in with OAuth; there is no API key.