MotherDuck's DuckDB MCP Server is an MCP server implementation that interacts with DuckDB and MotherDuck databases, providing SQL analytics capabilities to AI Assistants and IDEs. It supports hybrid execution by querying data from local DuckDB instances and cloud-based MotherDuck databases, and it can access data stored in cloud storage (e.g., Amazon S3) via MotherDuck's integrations. Data sharing is supported by creating and sharing databases. Queries use DuckDB's SQL dialect and can be issued from AI assistants or IDEs; all interactions are performed by writing SQL queries. The server operates in a serverless fashion, removing infrastructure management. It exposes one initialization prompt, 'duckdb-motherduck-initial-prompt', and one tool, 'query', to execute SQL on the active database. Query results are automatically limited to 1024 rows and 50,000 characters by default (configurable via --max-rows and --max-chars); responses may be truncated with a note. The MCP supports connecting to MotherDuck with tokens (including SaaS mode) or to local DuckDB (memory or file) or DuckDB on S3 with credentials loaded from environment variables. It also supports read-only operation and short-lived connections.