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# Plugging an MCP Server into the AI Assistant

# 🔌 Plugging an MCP Server into the AI Assistant

An MCP connector gives the AI assistant extra tools: reading your Notion pages, querying a business service, triggering an action somewhere else. Once plugged in, the assistant uses it on its own in the Text chat.

${frame}[Video: connecting an MCP server](https://celestory-docs-videos.netlify.app/en/geste-ui/connect-an-mcp-server.html)

## 🧭 Where This Happens

Open the **AI Generation** window (shortcut `Cmd+Shift+G`), then the **Tools** tab: your connectors are shown there as cards, with the **Add a connector** button.

## ➕ Creating a Connector

The button opens the **Custom MCP connector** dialog, with four fields:

-   **Title**: the name shown on the card. Required.
-   **Server**: the address of the MCP server. Required.
-   **Description**: optional.
-   **Authentication method**: see below.

The **Connect** button creates the connector, then Celestory queries the server to discover its tools. The connector sheet then opens, with two tabs: **Overview** and **Functions**.

## 🔐 The Four Authentication Methods

-   **No authentication**: nothing to fill in.
-   **API token**: you paste a token, presented to the server on every call.
-   **JSON headers**: your own headers, as a JSON object. Malformed JSON is flagged before saving.
-   **OAuth**: no secret to type in. Celestory queries the server, registers itself with it and takes you to its consent page.

When you pick OAuth, the dialog displays: "The authorization opens in a window right after the connector is created." You approve on the service's own site, the window closes, the sheet switches to **Connected** and two buttons appear: **Authorize again** and **Disconnect**.

🔺 If your browser blocks pop-up windows, nothing starts: allow pop-ups for the site, then try again.

🔺 An authorization left pending for more than ten minutes expires, and has to be started over from Celestory.

**Your secrets stay server-side.** A stored token is never sent back to the interface: the fields come back empty, and only the method used and the connection state are displayed. Typing a value again replaces the old one; typing nothing leaves it in place.

**Renewal is automatic.** Celestory renews access before it expires, and if the service still refuses a call, it retries once with fresh access. You only step in if the service granted no renewal at all: the connector stops answering, and **Authorize again** restores access.

## 🧰 The Functions Tab

It lists the tools exposed by the server, with their description and a counter. **Refresh tools** runs discovery again.

Each tool carries an **Allow** switch. Turning it off leaves the tool visible in the list, but it is never offered to the assistant again: handy for letting nothing but reads through.

## 🎚️ Switching Off Without Deleting

In the **Overview** tab, the **Enabled** switch turns off the whole connector: its card goes to **Disabled** and the assistant ignores it, without losing its configuration or its authorization. **Delete** asks for a confirmation.

## 👥 Connectors Belong to the Project

A connector is attached to the **project**, not to your account. Anyone who can edit the project sees the same connectors, and an authorization granted by one member serves the whole team. Conversely, a connector does not show up in your other projects.

## 🔺 Not Every Model Can Use Tools

Some models cannot call tools. If you select one while a connector is active, a banner appears in the Tools tab and in the Text chat. The model will answer normally, but will use **no** connector at all. Pick a tool-capable model.

## 📏 Limits Worth Knowing

-   The number of connectors is not capped.
-   At most 128 tools are presented to the assistant for a given turn; beyond that, the rest are ignored.
-   The assistant chains at most 8 rounds of tool calls for a single answer.

## 🛠️ When It Does Not Work

If the server is unreachable or refuses the connection, the card switches to **Connection error** and the exact message is shown in the sheet. During a conversation, a failing connector is simply set aside: the assistant carries on with the others.

→ Next step: in the **Functions** tab, switch off the tools you do not need, then ask the assistant for something in the Text chat to watch it use them.