Custom Connectors are ideal when you need to connect to a service that isn’t listed in our pre-configured third-party Connectors directory.

Built on the Model Context Protocol (MCP), they give you the flexibility to quickly integrate with a wide variety of tools and services.

Let’s walk through how to create one.

🔑 This feature is reserved for users with Admin privileges. All le Chat Free / Pro / Student account owners are Admin by default.

Steps to create a Custom Connector

1. Navigate to the Connectors page

Within le Chat interface, if not already open, click the toggle panel button (1) then click Connectors (2).

Click Connectors

2. Click "Add Connector"

Locate the + Add Connector button on the right side of the page, then click it.

This opens the MCP Connectors directory.

Clicking the + Add Connector button

3. Configure the Connector

At the top of the MCP Connectors directory pop-up, click the Custom MCP Connector tab to switch to the Custom MCP Connector creation form.

You will be prompted to enter the following details:

Connector name: Enter a unique name for your Connector (no spaces or special characters). This name will be used to identify the Connector in your organization.
Connection server: Enter the full URL of the MCP-compatible server. (⚠️ Be sure to add only trusted servers, see below for more details).
Description (Optional): Provide a clear, human-readable description of what this Connector does.
Authentication method: Select the authentication method that is supported by your server (see below for more details).

Entering the server URL and description for the new Custom Connector.

Once you have entered the details, click the Connect button. The platform will attempt to connect to the server and if applicable, will guide you through the authentication process.

Example of OAuth 2 client authentication

4. Your Connector is created!

If the connection is successful, your new Custom Connector will appear in your organization’s list of connections, ready to be enabled and used by your team.

Next steps

🧑‍💼 I am a user and I want to use my new Connector within le Chat.

Additional Resources

Security warning

🚨 Custom Connectors let you hook Mistral le Chat up to services that have not been reviewed or verified by Mistral. Only connect to remote MCP servers you trust. Mistral won’t be responsible for any misuse of your data.

Some best practices to keep in mind:

Watch for unexpected changes from your MCP server. Server developers can update tools, which might lead to unintended behavior.
Be mindful of prompt injections. A malicious server could try to slip in hidden instructions. Mistral le Chat has protections, but you should still scrutinize tool inputs and outputs and stick to trusted servers.
Pay attention to the permissions you grant. Only allow what you need and avoid unnecessary access.

🥷 Stay safe! If you discover a malicious MCP server, please report it to our support team.

Supported authentication methods

The authentication type for a Custom Connector is automatically detected by our platform when you provide the server URL during the setup process. The currently supported methods are:

No Authentication: For servers that are publicly accessible or on a trusted internal network and do not require authentication.
HTTP Bearer Token / Basic Auth: For servers that require credentials or a token to be sent in the Authorization header of each request.
OAuth 2.1 (with Dynamic Client Registration): For servers that use the standard OAuth 2.1 protocol for secure, delegated access. If this is detected, the user connecting the service will be guided through the standard OAuth consent flow.

Once configured, our system handles the detection and subsequent authentication flow automatically. In case of OAuth 2.1, the user will be prompted to log in and grant permissions to the application.

MCP Connector function user-level permissions

Once configured, every user can control whether le Chat asks for permission every time it wants to use a function, or if it should always be allowed.

🔑 This is useful for preventing repetitive permission requests for functions that are frequently used but not sensitive.

To manage function permissions:

Navigate to the Connectors page and ensure you are on the My Connectors tab.
Click the Custom Connector card to open its details.
Go to the Functions tab.
For each function listed, you can toggle the Always Allow setting.