The Tools tab lets you connect **MCP** servers — external tools (a database, an online spreadsheet, a business service) that the AI assistant can use itself during your conversation in the Text tab.
### How does it work?
Imagine giving the AI access to a shared spreadsheet: instead of answering only with what it already "knows", it can look inside live, search for a specific piece of information, or even write data into it, before answering you. That is what this tab enables, through a technology called **MCP** (Model Context Protocol) — a shared language that lets the AI "talk" to external tools, a bit like a universal plug.

In practice: you click **Add a connector**, give it a title and the server address, and Celestory queries that server to discover the tools it exposes. Each tool then has its own **Allow** switch, so you can let through only what you want.

🔺 **Authentication is manual.** Three methods only: no authentication, **API token** (you paste a token) or **JSON headers** (you write the headers yourself). There is **no "Sign in with…" OAuth button**: a service that accepts OAuth only cannot be connected today.

🔺 A connector belongs to the **project**, not to your account: anyone who can edit the project sees the same connectors.

🔺 **At most 128 tools** are presented to the assistant for a given turn; beyond that, the rest are ignored.

⚠️ Not all models can use tools. If you pick a non-capable model while a connector is active, a warning banner appears: the model will answer normally but will use no connector at all.

👉 The full procedure (connector cards, Functions tab, disabling, troubleshooting): [Plugging an MCP Server into the AI Assistant](Connecteurs_MCP.md).
### Use Cases
- 🗄️ **Query a database live**: ask, in natural language, about the contents of a connected Airtable or Baserow base without leaving the chat.
- 🔄 **Update a record**: ask the AI to add or change a row in a connected external tool.
- 🧰 **Equip the graph assistant**: give it access to your business reference data so it builds the story from real content.
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