Connect to MotherDuck

Source Of Truth

Prefer current MotherDuck connection, attach-mode, read-scaling, and multithreading docs.
If the MotherDuck MCP ask_docs_question tool is available, use it first for current connection behavior.
When it is unavailable, verify guidance against the public docs before making firm claims about connection strings, token types, or read-scaling behavior.

Start with the PG endpoint (MotherDuck's Postgres-compatible endpoint) for backend applications, BI tools, and serverless runtimes that want PostgreSQL wire compatibility.
For BI tools, treat the PG endpoint as the compatibility path for Power BI and Tableau Cloud when current docs list them as supported.
Use the native DuckDB API when you need local files, hybrid local/cloud execution, or direct DuckDB control.
Use md: workspace connections for multi-database exploration, bootstrap flows, and temporary validation environments.
Reuse an existing connection, connector, or environment-managed token when the user's context already provides one; do not ask for secrets that can be discovered from the active workspace.
Start with one connection. Add pooling or read scaling only when real concurrent-read pressure exists.
Use native DuckDB custom_user_agent where supported; for PG endpoint clients, prefer the client's application_name setting when available.