SPTAG
MicrosoftSPTAG (Space Partition Tree And Graph) is a Microsoft Research and Bing library for large-scale approximate nearest neighbour search, combining kd-tree or balanced k-means tree partitioning with a relative neighbourhood graph. It supports online insertion and deletion and a distributed search mode across machines.
Distinct from diskann - a different Microsoft Research ANN algorithm family (tree-plus-graph rather than Vamana), maintained independently. sptag on PyPI is declared as the measurement identity because, unlike diskannpy, it is built from this repository's root `setup.py` against the current code by the Microsoft SPTAG team, and the library has no server for it to be a client of; installing it gives you SPTAG. Its count is small because most users build the C++ library directly, which the adoption note records.
Openness
5 high confidence- license
- MIT(OSI)
- source
- public
- core features withheld
- no
MIT license body confirmed. The repository is public and unarchived and builds the whole library, and the README describes no paid tier, enterprise edition or license-gated build beside it.
- https://api.github.com/repos/microsoft/SPTAG recorded 2026-09-02
Repo metadata - license spdx_id MIT, private false, archived false, default branch main - for microsoft/SPTAG.
- https://github.com/microsoft/SPTAG/blob/main/LICENSE recorded 2026-10-07
LICENSE file is the verbatim MIT text under a Microsoft Corporation copyright line.
- https://github.com/microsoft/SPTAG/blob/main/README.md recorded 2026-10-07
README describes an approximate nearest neighbour search library with no paid tier, enterprise edition or license-key-gated build beside the MIT-licensed code.
Adoption
1 medium confidenceSPTAG's adoption reading comes from PyPI downloads of the `sptag` package, since SPTAG is a C++ library with Python bindings and no separate server, so the package figure is a direct read of usage. Most users build the C++ library directly rather than installing it through PyPI, so this reading captures only a slice of overall use.
- https://pypistats.org/api/packages/sptag/recent recorded 2026-09-02
last_month downloads = 77 for sptag.
Capability
3 medium confidenceSPTAG combines two index families — kd-tree and balanced k-means tree, each paired with a relative neighbourhood graph — with online insertion, deletion and distributed search across machines. That puts it alongside Faiss: both are search toolkits rather than durable, transactional stores, so neither reaches the complete, distributed systems at the top of the category.
- https://github.com/microsoft/SPTAG/blob/main/README.md recorded 2026-10-07
README documents two index families, online insert/delete, and a distributed serving mode across multiple machines.
Verified 2026-09-23