n8n MCP Client

Connect your Alation catalog to n8n using the Remote MCP server with OAuth authentication.

Prerequisites

• OAuth Client credentials from your Alation instance or a Server Admin role to create one.
• n8n instance with built-in MCP Client Tool node support

Add an MCP Client Node in n8n

1. Search for MCP Client Tool

   In the n8n editor, search for “MCP” in the node panel. Select MCP Client Tool under “Model Context Protocol” (the built-in node, not the community package).

   

2. Configure server transport

   Set the following parameters:

   Field	Value
   Server Transport	HTTP Streamable
   MCP Endpoint URL	https://<YOUR_INSTANCE>.alationcloud.com/ai/mcp

   

Connecting (Authentication)

Alation supports two authentication methods:

Method	Use Case
MCP OAuth2	Recommended for user-delegated access
Bearer Auth	Service account style access (requires manual token refresh)

MCP OAuth2 Setup

1. Select MCP OAuth2 authentication

   In the Authentication dropdown, select MCP OAuth2, then click the credential dropdown and select Create New Credential.

2. Disable Dynamic Client Registration

   Toggle Use Dynamic Client Registration to Off. This reveals the manual OAuth configuration fields.

   

3. Note the OAuth Redirect URL

   Copy the OAuth Redirect URL shown at the top of the form (e.g., http://localhost:5678/rest/oauth2-credential/callback). You’ll need this when creating your OAuth Client in Alation.

4. Create an OAuth Client in Alation

   Refer to the OAuth 2.0 User Initiated Authentication Guide to create an OAuth Client. Use these settings:

   Field	Value
   name	Any name (e.g., n8n-mcp-client)
   client_type	confidential
   redirect_uris	The OAuth Redirect URL from Step 3
   refresh_token_expiry	259200 (3 days in seconds)
   access_token_expiry	3600 (1 hour in seconds)
   pkce_required	true

   Save the client_id and client_secret securely.

5. Configure OAuth2 credentials

   Fill in the credential form:

   Field	Value
   Grant Type	PKCE
   Authorization URL	https://<YOUR_INSTANCE>.alationcloud.com/oauth/v1/authorize/
   Access Token URL	https://<YOUR_INSTANCE>.alationcloud.com/oauth/v1/token/
   Client ID	Your client ID from Alation
   Client Secret	Your client secret from Alation
   Scope	Leave blank
   Auth URI Query Parameters	Leave blank
   Authentication	Header

   

6. Connect your account

   Click Connect my account. A browser window opens for Alation login. Sign in with your credentials.

7. Verify connection

   After signing in, you’ll see “Account connected”. Click Save to close the credential dialog.

   

Bearer Auth setup

1. Obtain an access token

   Refer to the OAuth 2.0 M2M Authentication Guide to create an OAuth Client and obtain an access token.

2. Configure Bearer Auth

   Select Bearer Auth from the Authentication dropdown, then enter your access token.

   

3. Save credentials

   Click Save to close the credential dialog.

Troubleshooting

• n8n version compatibility? Ensure you’re running n8n version 1.93 or later, which includes built-in MCP Client Tool support with OAuth.

• Zscaler or VPN issues with localhost? When running n8n locally (localhost), disable Zscaler or other security proxies before attempting the OAuth flow, as they can interfere with the authentication redirect.

• OAuth flow fails or loops? Log out of any existing Alation sessions in your browser before attempting the OAuth login.

• Authentication errors? Verify the Authorization URL and Access Token URL include a trailing slash (e.g., .../authorize/ not .../authorize).

• Token expired with Bearer Auth? Bearer tokens need manual refresh when they expire. Consider using MCP OAuth2 for automatic token refresh.