The Rust engine¶

duckOSM builds the road networks with an engine in Rust. It is the default since 2026-11-04. It gives the same tables and the same edge_id values as the old Python engine, and it is much faster.

Area	Rust engine	Python engine
Estonia, the network step	19 s, 1.5 GB of memory	1,545 s, 10 GB of memory

What runs in Rust¶

Step	Engine
The network: `edges`, `private_edges`, `nodes`, `edge_id_map`, `edge_graph`, turn restrictions	Rust
`raw.*` of a whole file in the program `duckosm-rust`: the table function `read_osm`, about 30% less CPU than `ST_READOSM` (design)	Rust
The osmium cut, `raw.` of `duckosm build`, the base-map layers (`features.`), the bus routes, the drawing levels	Python, for now

The Python steps move to Rust one at a time. Each move has a test that the tables stay equal.

Choose the engine¶

The engine is the option options.engine of the configuration:

options:
  engine: rust      # the default; python runs the old SQL steps

On the command line, duckosm build --engine python ... uses the Python engine. The Python engine stays as the reference for one release.

Install¶

The Rust engine is the module duckosm._rust, inside the duckosm wheel. You do not install it separately. There are wheels for Linux (x86_64 and aarch64), macOS (x86_64 and arm64) and Windows (x64). On another system, pip builds the package from the source, and that needs a Rust toolchain.

The program duckosm-rust¶

The folder rust/ also has a program with no Python: duckosm-rust. It builds an area from a config or from a cut .osm.pbf file.

cargo build --release --manifest-path rust/Cargo.toml -p duckosm-cli   # makes rust/target/release/duckosm-rust
rust/target/release/duckosm-rust --config my_area.yaml --allow-skipped
rust/target/release/duckosm-rust edit my_area.duckdb                   # the page of Edit OSM data

--allow-skipped lets the build go on when the config asks for a step that only Python has (for example the base-map layers). duckosm-rust --help lists all the options.

In the browser¶

duckOSM Studio runs the same engine as WebAssembly. It builds the same tables in a web page, with nothing to install.

For developers¶

The design and the measurements are on GitHub: the engine, the move into duckOSM and the Rust documents.