What is the Weld MCP?

The Weld MCP lets you manage your data warehouse and ELT pipelines using your favourite familiar tools - Claude Code, Claude Desktop, Cursor, GitHub Copilot, or Windsurf. List syncs, inspect connections, debug a pipeline, or create a new SQL transform and do it all converstionally without a worrying about syntax or hours of work.

The Model Context Protocol (MCP), is an open standard for connecting AI assistants to external tools. You connect once, and your assistant instantly knows how to work with your Weld workspace - no APIs to wire up, no custom integration to maintain.

Curious what you can actually do with it? Read more about what you can do with the Weld MCP →.

Before you start

You'll need a few things in place:

  • A Weld account on the Premium plan or above - Have a look at our plans on the pricing page.
  • Connection methods include:
    • OAuth (recommended) - nothing to set up; you log in with your Weld account in a browser.
    • API key - create one in the Weld app under Settings → API keys (workspace.weld.app).
  • The endpoint every client connects to: https://connect.weld.app/mcp (Streamable HTTP transport).

Setup guide

Pick the path that matches your tool. OAuth is the smoothest if you're on Claude, so we'll start there.

Option 1 (Recommended): Claude tools via OAuth

The easiest way to connect. There's no API key to create or store - you just log in.

Claude Desktop & claude.ai

In Claude Desktop or on claude.ai, you can connect Weld straight from the Connectors menu - no config file needed.

  1. Open Settings → Connectors.
  2. Click Add custom connector.
  3. Give it a name (for example, Weld) and paste in the endpoint: https://connect.weld.app/mcp
  4. Click Add. A browser window opens - log in with your Weld account to authorize the connection.
  5. That's it. Weld's tools are now available right in your chat.
Connecting Claude Desktop to Weld via OAuth

Claude Code

  1. Add the server (no API-key header needed for OAuth): 
    claude mcp add weld --transport streamable-http https://connect.weld.app/mcp
  2. Run /mcp inside Claude Code and complete the browser login when prompted.

Connecting with OAuth and have more than one workspace? If your Weld account can access several workspaces, tell the server which one to use by adding your account ID to the URL: https://connect.weld.app/mcp?account_id=<YOUR_ACCOUNT_ID>. Don't know your account ID? Connect without it first - the server gives you a list_accounts tool that lists your workspaces and their IDs.

Option 2: Config file using an API key

For tools that don't use OAuth - or if you'd rather use a static key. Create your key under Settings → API keys and pass it in the x-api-key header.

Security note: Keep your API key secret. Don't commit it to version control - use environment variables or a secrets manager wherever you can.

Claude Code

claude mcp add weld --transport streamable-http https://connect.weld.app/mcp \
  --header "x-api-key: <YOUR_WELD_API_KEY>"

Cursor

Add this to .cursor/mcp.json (project) or ~/.cursor/mcp.json (global):

1{
2  "mcpServers": {
3    "weld": {
4      "url": "https://connect.weld.app/mcp",
5      "headers": {
6        "x-api-key": "<YOUR_WELD_API_KEY>"
7      }
8    }
9  }
10}

VS Code (GitHub Copilot)

Add this to .vscode/mcp.json (project) or your user settings. Note the key is servers, not mcpServers:

1{
2  "servers": {
3    "weld": {
4      "url": "https://connect.weld.app/mcp",
5      "headers": {
6        "x-api-key": "<YOUR_WELD_API_KEY>"
7      }
8    }
9  }
10}

Windsurf

Add this to your Windsurf MCP configuration file. Note the key is serverUrl, not url:

1{
2  "mcpServers": {
3    "weld": {
4      "serverUrl": "https://connect.weld.app/mcp",
5      "headers": {
6        "x-api-key": "<YOUR_WELD_API_KEY>"
7      }
8    }
9  }
10}

Headless / programmatic (for developers)

Calling the MCP server directly from CI, a script, or a custom client? Connect to https://connect.weld.app/mcp over the Streamable HTTP transport and send your key in the x-api-key: <YOUR_WELD_API_KEY> header on every request. The server is stateless, so there's no session to open or expire.

Mind the rate limits: 60 requests per minute per account and 10 authentication attempts per minute per IP address. Exceed either and you'll get a 429 Too Many Requests response.

Test your connection

Once you're set up, confirm everything's working by asking your assistant:

List my Weld connections.

Your assistant calls the list_connections tool and returns your data sources. If you see them listed, your connection is live and ready to go.

Further resources