Data shared with AI

Ed, the assistant in the model editor, and AI tools connected through the Weld MCP server can work with your data warehouse in two ways:

• Metadata only — the AI sees table and column names, column types and SQL, but never any values from your data.
• Metadata and data — the AI can also run read-only queries on your warehouse and read their results. Those results are sent to the language model behind the tool.

Which of the two applies is set per workspace with the Send metadata only setting.

What the AI can do with metadata only

With Send metadata only turned on, Ed and MCP clients can still:

• Search your tables and models, and read their column names and types
• Write and propose SQL for you to run
• Check that a query is valid and see which columns it would return, without returning any rows
• For MCP clients, manage syncs, transforms, orchestrations and the rest of your workspace, as your permissions allow

They cannot:

• Run queries on your warehouse or read query results (run_query, get_query_status and get_query_result in the MCP server)
• Read failed reverse ETL records (get_reverse_etl_sync_failed_record_errors)
• Read error messages from sync, transform and reverse ETL runs. A warehouse error can quote a value from your data, for example the cell that failed to convert, so these messages are replaced with a note that they were withheld. The status of the run is still shown.

When a question needs values from your data, Ed tells you so and suggests a query you can run yourself. Query results from earlier in a conversation are hidden from Ed too.

Change the setting

Only workspace admins can change this setting.

1. In the Weld app, open Settings → AI.
2. Under Data shared with AI, switch the Send metadata only toggle:
   • On — Ed and MCP clients get metadata only.
   • Off — Ed and MCP clients can run read-only queries and read their results.

The change applies straight away to Ed and to every connected MCP client, including conversations that are already open. Changes to the setting are recorded in the workspace's audit log.