#1717th of 22 in Vector databases

sptag

C++ library for approximate nearest neighbor search over large vector sets

Stars
5k
License
MIT
Last commit
Sep 2026
Language
C++
Stars, last 29 weeks+56
22 Apr 2026: 4,965 stars29 Apr 2026: 4,967 stars6 May 2026: 4,972 stars13 May 2026: 4,977 stars20 May 2026: 4,979 stars27 May 2026: 4,983 stars3 Jun 2026: 4,984 stars10 Jun 2026: 4,987 stars17 Jun 2026: 4,989 stars24 Jun 2026: 4,990 stars1 Jul 2026: 4,990 stars8 Jul 2026: 4,993 stars15 Jul 2026: 4,995 stars22 Jul 2026: 4,995 stars29 Jul 2026: 4,998 stars5 Aug 2026: 5,000 stars12 Aug 2026: 5,000 stars19 Aug 2026: 5,001 stars26 Aug 2026: 5,002 stars2 Sept 2026: 5,006 stars9 Sept 2026: 5,008 stars16 Sept 2026: 5,008 stars23 Sept 2026: 5,012 stars30 Sept 2026: 5,015 stars7 Oct 2026: 5,016 stars14 Oct 2026: 5,017 stars21 Oct 2026: 5,017 stars28 Oct 2026: 5,018 stars4 Nov 2026: 5,020 stars11 Nov 2026: 5,021 stars

4,965 on 22 Apr 20265,021 on 11 Nov 2026

From GitHub's daily star counts.

Checked on GitHub.

Overview

SPTAG is a Microsoft Research and Bing library for approximate nearest neighbor search over vectors using L2 or cosine distance. It offers two index types: SPTAG-KDT (kd-tree plus relative neighborhood graph) and SPTAG-BKT (balanced k-means tree plus graph). It supports online insertion and deletion, and search across multiple machines.

Who it is for: Engineers embedding large-scale vector search in C++ or Python systems

Strengths

  • Two index types: KDT for cheaper builds, BKT for accuracy on very high-dimensional data
  • Supports online vector insertion and deletion without a full rebuild
  • Distributed serving across multiple machines
  • Backed by published papers (SPANN, SPFresh, VBASE) and MIT licensed

Weaknesses

  • Source build needs swig, cmake and boost; optional SPDK and RocksDB builds are involved
  • Only L2 and cosine distances are documented
  • No tagged releases; build from source or the Dockerfile
  • Library, not a standalone server; an online service needs the Python wrapper

What it needs

  • Docker
  • Needs swig >= 4.0.2, cmake >= 3.12.0, boost >= 1.67.0, SPDK (optional), RocksDB (optional)

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