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fast command-line extensions for sourmash

Project description



tl;dr Do faster and lower-memory sourmash search & gather via a plugin.


sourmash is a command-line tool and Python/Rust library for metagenome analysis and genome comparison using k-mers. While sourmash is fast and low memory, sourmash v4 and lower work in single-threaded mode with Python containers.

The branchwater plugin for sourmash (this plugin!) provides faster and lower-memory implementations of several important sourmash features - sketching, searching, and gather (metagenome decomposition). It does so by implementing higher-level functions in Rust on top of the core Rust library of sourmash. As a result it provides some of the same functionality as sourmash, but 10-100x faster and in 10x lower memory.

This code is still in prototype mode, and does not have all of the features of sourmash. As we add features we will move it back into the core sourmash code base; eventually, much of the code in this repository will be integrated into sourmash directly.

This repo originated as a PyO3-based Python wrapper around the core branchwater code. Branchwater is a fast, low-memory and multithreaded application for searching very large collections of FracMinHash sketches as generated by sourmash.

For details, see the Rust code in src/ and Python wrapper in src/python/.


There is a quickstart below, as well as more user documentation here. Nascent developer docs are also available!

Quickstart for manysearch.

This quickstart demonstrates multisearch using the 64 genomes from Awad et al., 2017.

1. Install the branchwater plugin

On Linux, you can install the branchwater plugin from conda-forge:

conda install sourmash_plugin_branchwater

On other platforms (such as Mac OS X) you'll need to install the branchwater plugin in a development environment; please see the developer docs for information.

2. Download sketches.

The following commands will download sourmash sketches for the podar genomes into the file

curl -L -o

3. Execute!

Now run multisearch to search all the sketches against each other:

sourmash scripts multisearch -o results.csv --cores 4

You will (hopefully ;)) see a set of results in results.csv. These are comparisons of each query against all matching genomes.

Debugging help

If your collections aren't loading properly, try running sourmash sig summarize on them, like so:

sourmash sig summarize

This will make sure everything can be loaded properly.

Code of Conduct

This project is under the sourmash Code of Conduct.


This software is under the AGPL license. Please see LICENSE.txt.


  • Luiz Irber
  • C. Titus Brown
  • Mohamed Abuelanin
  • N. Tessa Pierce-Ward

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sourmash_plugin_branchwater-0.8.5.tar.gz (22.1 MB view hashes)

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