Dependencies

ClickHouse is a self-contained C++ binary with everything statically linked. Third-party libraries live as submodules under contrib/. The repo currently has 256 contrib submodules (an entry per *-cmake directory or library directory).

This page is a guided tour, not an exhaustive list. Run ls contrib/ for the full listing.

Why vendor everything?

• Reproducibility. No surprise from system library updates. Every build at a given commit pulls the same dependency commits.
• Single static binary. clickhouse-server doesn't dynamically link against anything outside libc / libpthread / libstdc++.
• Patches. ClickHouse maintains internal patches over many libraries. Vendoring is the only way to keep them coherent.
• Cross-compilation. A bundled toolchain (LLVM/Clang) plus contrib/ builds on Linux x86_64, aarch64, RISC-V, PowerPC, s390x, FreeBSD, and macOS.

Categories

Storage / formats / lakehouse

• arrow, avro, protobuf, capnproto, simdjson, rapidjson, flatbuffers, msgpack-c, numpy-c-cmake, mongo-c-driver.
• aws*, azure, aws-crt-cpp, aws-c-* — S3 and Azure SDK split into many small libs.
• delta-kernel-rs — Delta Lake table-format reader.
• apache-iceberg-tools — Iceberg helpers.
• librdkafka (via cppkafka).
• nats.c.
• amqpcpp (AMQP-CPP).
• librocksdb (RocksDB) — backs EmbeddedRocksDB and Keeper's RocksDB log.
• unixodbc, nanodbc — ODBC bridge.
• bzip2, lz4, zstd, xz, zlib-ng, snappy — compression codecs.

Networking

• boost, boost-cmake.
• c-ares, libcurl-cmake, wolfssl-cmake, openssl (boringssl-cmake), s2n-tls, nuraft.
• pocoproject-poco — used pervasively for HTTP, XML, threading.
• grpc and protoc-gen-validate-cmake.

SQL parsing and query

• antlr4-cpp-runtime, antlr4-grammars — used by some adapters.
• re2, vectorscan (Hyperscan fork) — regex engines.
• usearch + SimSIMD — vector search.
• xxhash, wyhash, farmhash, cityhash102 (vendored) — hash families.
• hyperscan (the original).

Cryptography and hashing

• boringssl-cmake, cyrus-sasl-cmake, gostssl, nettle-cmake, s2n-tls.
• sha3iuf-cmake, morton-nd-cmake.

Date / time / locale

• cctz, cctz-cmake, unicode-data, unicode-c, icu, icu-cmake.

LLVM / JIT / fuzzing / tooling

• llvm-project — used both as the vendored compiler toolchain and for runtime JIT (src/Interpreters/JIT/).
• libcxx, libcxxabi, libunwind — vendored libc++.
• libfuzzer-cmake.

Database integrations

• mariadb-connector-c, libpqxx, libpq, mongo-c-driver, mongocxx-c, cassandra-cpp-driver, redis-plus-plus, aerospike-client-c, prometheus-cpp.

Geo / math

• s2geometry-cmake, h3-cmake, boost-geometry, liburing (Linux io_uring), eigen-cmake.
• fastfloat, dragonbox.

XML / YAML / TOML / JSON

• pocoproject-poco, rapidjson, simdjson, yaml-cpp-cmake, tomlplusplus.

Misc

• replxx — line editor for the client.
• skim — fuzzy finder used by some tools.
• duckdb-cmake (the duck) — used in some experimental paths and tests.
• ai-sdk-cpp — recent addition for AI integrations.
• bech32, morton-nd-cmake, idn2-cmake.

Maintenance

• Submodules are committed at exact SHAs. git submodule update --init --recursive brings them in.
• Each <lib>-cmake/ directory is the in-tree CMake recipe; the upstream sources are untouched.
• Renovation typically happens via PRs that bump submodule pointers and adapt the cmake files.

Runtime dependencies

clickhouse-server static binary needs:

• A modern Linux (kernel 3.10+, but glibc 2.17+ is the practical floor; musl works too).
• libc, libpthread, libdl, librt.
• libstdc++ (linked statically when built with bundled libcxx).

That's it. There are no required runtime services beyond what the operator configures (Keeper, S3, Postgres, …).

Build dependencies

• A C++20 compiler (the project uses Clang 16+, vendored).
• CMake 3.20+.
• Ninja or Make.
• Python 3 (test runner and build helpers).
• Rust toolchain — for rust/ crates wired into the binary (prql, corrosion, delta-kernel-rs, tantivy_search, chdig, …). The build pulls them into the C++ link stage.

See Getting started for the build walkthrough.

Related pages

• Tooling
• Getting started