Language bindings (in-tree)

tools/juliapkg/ and tools/swift/ are small in-tree packages that wrap the C API. The Python, R, Node.js, JDBC, Go, Rust, ODBC, and Wasm clients live in separate repositories (https://github.com/duckdb/) and are not part of this codebase.

Julia

tools/juliapkg/ is a Julia package (DuckDB.jl) that ships in this repo because it is tightly coupled to the engine's release cadence.

tools/juliapkg/
├── Project.toml         Julia package manifest
├── src/                 Wrapper sources
├── test/                Tests
└── ...

It builds against the shared library produced by make plus the C header src/include/duckdb.h. The package exposes:

• DuckDB.DB(path) — open a database.
• DBInterface integration so it works with DBInterface.execute(...).
• DataFrames.jl integration via DBInterface.fetch.

For development, add tools/juliapkg/ as a Pkg dependency pointing at the local checkout. CI for the Julia package runs through .github/workflows/Main.yml together with the C++ build.

Swift

tools/swift/ is a Swift package that wraps the same C API. It is mostly used by macOS / iOS embedders.

tools/swift/
├── Package.swift        Swift package manifest
├── Sources/             Wrapper code
└── Tests/               XCTest cases

The Swift binding's release matrix is driven by .github/workflows/Swift.yml and SwiftRelease.yml.

utils

tools/utils/ is a small helper directory with development utilities used by the in-tree clients (e.g., shared test fixtures). It is not user-facing.

Out-of-tree clients

For everything else, see the per-client repositories:

Client	Repository	Notes
Python	duckdb/duckdb-python (or the tools/pythonpkg/ historical path; the modern source is in a separate repo)	The most heavily used binding. Includes pandas / pyarrow / Arrow integration.
R	duckdb/duckdb-r	Includes dplyr integration via duckplyr.
Node.js	duckdb/duckdb-node	Includes both the legacy duckdb and the newer duckdb-async packages.
JDBC / Java	duckdb/duckdb-java	JDBC driver.
ODBC	duckdb/duckdb-odbc	ODBC driver.
Wasm	duckdb/duckdb-wasm	The browser/Node Wasm build.
Go	marcboeker/go-duckdb	Community-maintained.
Rust	duckdb/duckdb-rs	Rust bindings.

These all use the C API exposed by systems/main and link against amalgamation builds produced by scripts/amalgamation.py.

See also

• tools/cli-shell — the CLI shipped in this repo.
• systems/main — the C API everyone wraps.
• how-to-contribute/tooling — scripts/amalgamation.py and related build scripts.