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Mosaic DuckDB Server

The Mosaic duckdb-server package provides a Python-based server that runs a local DuckDB instance and support queries over Web Sockets or HTTP, returning data in either Apache Arrow or JSON format.


This package provides a local DuckDB server. To instead use DuckDB-WASM in the browser, use the wasmConnector from the mosaic-core package.


DuckDB can also connect to and query other databases, such as PostgreSQL and MySQL. See the multi-database support page for examples.


The server package is available on PyPi.

We recommend running the server in an isolated environment with pipx. For example, to directly run the server, use:

pipx run duckdb-server

Alternatively, you can install the server with pip install duckdb-server. Then you can start the server with duckdb-server.

Developer Setup

To run the server from the Mosaic repository and to run the server in development mode, follow the instructions for the duckdb-server package.