This document will help you to build the Knowhere repository from source code and to run unit tests. Please file an issue if there's a problem.

Knowhere is written in C++. It is an independent project that act as Milvus's internal core.

If you wish to only use Knowhere within Milvus without changing any of the Knowhere source code, we suggest that you move to the Milvus main project and build Milvus directly, where Knowhere is then built implicitly during Milvus build.

All Linux distributions are available for Knowhere development. However, a majority of our contributor worked with Ubuntu or CentOS systems, with a small portion of Mac (both x86_64 and Apple Silicon) contributors. If you would like Knowhere to build and run on other distributions, you are more than welcome to file an issue and contribute!

Here's a list of verified OS types where Knowhere can successfully build and run:

• Ubuntu 22.04 x86_64
• Ubuntu 22.04 Aarch64
• Ubuntu 20.04 x86_64 / Aarch64 (EOL by April 2025 and kept for legacy reasons; see scripts/install_deps.sh for details)
• MacOS (x86_64)
• MacOS (Apple Silicon)

scripts/install_deps.sh install all dependencies for building, testing, and shipping the knowhere library. If you don't need the full pipeline, please refer to the file and modify it for a more fine-grained dependency control.

$ bash scripts/install_deps.sh

A top-level Makefile provides a unified build interface. Run make help to see all targets and flags.

# CPU release (default)
$ make

# GPU release (cuVS)
$ make WITH_GPU=True

# CPU with unit tests
$ make WITH_UT=True

# CPU UT + AddressSanitizer
$ make WITH_UT=True WITH_ASAN=True

# GPU with unit tests
$ make WITH_GPU=True WITH_UT=True

# Debug build
$ make WITH_DEBUG=True

# Custom compiler via Conan profile (e.g. clang, gcc-15)
$ make CONAN_PROFILE=clang14

# requires a prior build with WITH_UT=True
$ make test

$ make clean

Building the Python wheel requires swig and Python development headers (python3-dev on Ubuntu). These are installed automatically by scripts/install_deps.sh.

After building Knowhere with a Release configuration:

# Build portable manylinux wheel
$ make wheel

# Install
$ pip3 install python/dist/pyknowhere-*-manylinux*.whl

For more options (clean build, verbose, custom Python binary), see python/build_portable_wheel.sh -h.

Before submitting a pull request, run pre-commit checks locally:

pip3 install pre-commit
pre-commit install --hook-type pre-commit --hook-type pre-push

# Run all pre-commit hooks
$ make pre-commit

# Or run individually:
$ make format   # clang-format
$ make lint     # clang-tidy (requires a prior build)

If clang-format and clang-tidy are not already installed:

# linux
apt install clang-format clang-tidy
# mac
brew install llvm
ln -s "$(brew --prefix llvm)/bin/clang-format" "/usr/local/bin/clang-format"
ln -s "$(brew --prefix llvm)/bin/clang-tidy" "/usr/local/bin/clang-tidy"