Dependencies

Third-party libraries Arrow uses, organized by how they're consumed: bundled (built from source as part of the Arrow build), system (linked from the host), or vendored (source code copied into the Arrow tree).

Configuration

Each dependency has a *_SOURCE CMake variable that selects how to find or build it. Values are:

• BUNDLED — fetch and build from source via ExternalProject.
• SYSTEM — find via find_package / pkg_check_modules.
• AUTO — try system first, fall back to bundled.

Defaults vary; the canonical list is in cpp/cmake_modules/ThirdpartyToolchain.cmake.

Core C++ dependencies

These are needed for the basic libarrow.so:

Library	Purpose	*_SOURCE flag	Notes
Boost	Headers (parts of boost::process, boost::filesystem)	Boost_SOURCE	Declining footprint; many uses migrated to C++17
FlatBuffers	IPC schema (format/*.fbs)	FlatBuffers_SOURCE	Version pinned because Arrow vendors generated headers
jemalloc	Memory pool backend	jemalloc_SOURCE	Optional; falls back to system allocator
OpenSSL	TLS for Flight, S3, Parquet encryption	OpenSSL_SOURCE	System on most platforms
zlib	Compression	ZLIB_SOURCE	Used by gzip codec
Snappy	Compression	Snappy_SOURCE	Used by Parquet, IPC
ZSTD	Compression	zstd_SOURCE	Used by Parquet, IPC
LZ4	Compression	lz4_SOURCE	Used by Parquet, IPC
Brotli	Compression	Brotli_SOURCE	Optional
BZ2	Compression	BZip2_SOURCE	Optional
RapidJSON	JSON parsing	RapidJSON_SOURCE	Header-only; vendored
utf8proc	UTF-8 case folding/normalization	utf8proc_SOURCE	Optional but enabled by default
re2	Regex	re2_SOURCE	Used by Gandiva and string kernels
xsimd	Portable SIMD	xsimd_SOURCE	Header-only; recently introduced
google-double-conversion	Float ↔ string	double_conversion_SOURCE	Vendored

Optional component dependencies

Pulled in only when the matching ARROW_* toggle is on:

Component	Library	Purpose
ARROW_PARQUET	Apache Thrift	parquet.thrift schema
ARROW_FLIGHT	gRPC + Protobuf	RPC framework
ARROW_FLIGHT_SQL	gRPC + Protobuf	RPC framework + SQL extension
ARROW_GANDIVA	LLVM	JIT compiler
ARROW_S3	AWS C++ SDK	S3 filesystem
ARROW_GCS	google-cloud-cpp	GCS filesystem
ARROW_AZURE	Azure C++ SDK	Azure Blob Storage filesystem
ARROW_HDFS	libhdfs (loaded dynamically)	HDFS filesystem
ARROW_ORC	Apache ORC C++	ORC adapter
ARROW_CUDA	CUDA toolkit	GPU support
ARROW_OPENTELEMETRY	OpenTelemetry C++	Tracing
ARROW_WITH_UCX	UCX	Flight UCX transport
ARROW_WITH_BACKTRACE	libbacktrace / libdw	Stack traces in Status
ARROW_PYTHON	Python + NumPy	C++ helpers PyArrow links against

The full list of toggles is in cpp/CMakeLists.txt.

Vendored libraries

Lives in cpp/src/arrow/vendored/:

• xxhash/ — xxHash 0.8.x.
• datetime/ — Howard Hinnant's date library.
• fast_float/ — Daniel Lemire's fast_float parser.
• double-conversion/ — Google's double-conversion (re-vendored even though there's a dependency, for consistent behavior).
• pcg/ — PCG random number generators.
• base64/, random/, string_view/ — small headers.
• portable-snippets/, ProducerConsumerQueue/ — concurrency helpers.

Vendored code is built as part of libarrow. Each subdirectory has its own LICENSE file.

Conda environment files

Each language has a ci/conda_env_*.txt file listing the conda packages needed for the build:

• ci/conda_env_cpp.txt — C++ build deps.
• ci/conda_env_python.txt — PyArrow build deps.
• ci/conda_env_r.txt — R build deps.
• ci/conda_env_gandiva.txt (and _win.txt) — Gandiva build deps including clangdev and llvmdev.
• ci/conda_env_archery.txt — archery CLI deps.
• ci/conda_env_crossbow.txt — Crossbow dispatcher deps.
• ci/conda_env_sphinx.txt — Documentation build deps.
• ci/conda_env_unix.txt — Common Unix tooling.

These are the source of truth for what version of each tool is expected to work.

Python dependencies

python/pyproject.toml lists the build deps. Runtime deps are minimal:

• numpy (always required for some converters).
• pandas (optional; only for to_pandas() / from_pandas()).

Build-time:

• Cython, numpy, setuptools, setuptools-scm, cffi (for the CFFI module), meson/scikit-build for the extension build.

Test-time deps live in python/requirements-test.txt, requirements-wheel-test.txt.

R dependencies

r/DESCRIPTION declares CRAN deps. The Imports: section pulls in assertthat, bit64, methods, purrr, R6, rlang, stats, tidyselect, vctrs. The Suggests: section pulls in dplyr, dbplyr, duckdb, lubridate, pkgload, reticulate, rmarkdown, stringi, stringr, testthat, tibble, withr.

For the bundled libarrow build, r/tools/nixlibs.R fetches Arrow C++ source and builds it.

Ruby dependencies

ruby/Gemfiles pull in gobject-introspection, pkg-config, test-unit. The actual GLib bindings are loaded at runtime via introspection; ruby/red-arrow/red-arrow.gemspec declares the C-GLib version requirement.

C-GLib dependencies

c_glib/Brewfile and c_glib/vcpkg.json list the system deps. The build needs:

• glib2 (≥2.58)
• gobject-introspection
• meson
• vala (optional, for Vala bindings)
• gtk-doc (optional, for the reference manual)

License compatibility

Arrow is Apache 2.0. All bundled and vendored dependencies use compatible licenses (MIT, BSD-3-Clause, Apache 2.0). The LICENSE.txt and NOTICE.txt at the repo root list the licenses of bundled and vendored components. The cpp/build-support/release/rat_exclude_files.txt lists files that the Apache RAT (Release Audit Tool) is allowed to skip during release verification.