sourmash v2.0 release notes

We are pleased to announce release 2.0 of sourmash! This release is the first full release of sourmash since 1.0, and provides much expanded core functionality as well as many more utility functions.

The full documentation for this version is available at Documentation for the latest released version is at

This release breaks compatibility with sourmash 1.0: the sourmash Python API, command-line, and signature file formats have all changed substantially. Please post questions about migrating to sourmash 2.0 in the sourmash issue tracker.

Major new features since 1.0

This is a list of substantial new features and functionality in sourmash 2.0.

  • Added Sequence Bloom Tree search to enable similarity and containment queries on very large collections of signatures in low memory; see sourmash index, sourmash search, and sourmash gather in the command line documentation.

  • Added “LCA databases” for fast searching of large databases in not-so-low memory; see sourmash lca index in command-line docs.

  • Created precomputed databases for most of GenBank genomes.

  • Added taxonomic reporting functionality in the sourmash lca submodule - see command-line docs.

  • Added signature manipulation utilities in the sourmash signature submodule - see command-line docs

  • Introduced new modulo hash or “scaled” signatures for containment analysis; see Using sourmash: a practical guide and more details in the Python API examples.

  • Switched to using JSON instead of YAML for signatures.

  • Many performance optimizations!

  • Many more tests!

  • A much cleaner and more robust Python API.

  • Installation via bioconda is now recommended (and actively maintained :)

  • Support for building signatures from BAM files.

Other features of note

  • Renamed Python library to sourmash from sourmash_lib.

  • Signatures now default to a license of CC0.

  • Implemented sourmash watch for classifying streams of data (see blog post).

  • Implemented sourmash categorize for classifying many signatures (see blog post).

  • CSV output enabled from most commands.