Protobuf provides first-class Bazel support. The protobuf repository itself is built with Bazel, and the provided rules integrate cleanly into any Bazel workspace.
Bzlmod (Bazel 8+)
WORKSPACE (legacy)
Add a dependency on protobuf in your MODULE.bazel file:bazel_dep(name = "protobuf", version = "VERSION")
VERSION with the desired release version (e.g., 29.0). Bzlmod resolves the highest compatible version across your module graph.If you need to keep the legacy com_google_protobuf repo name for compatibility with WORKSPACE-style references:bazel_dep(name = "protobuf", version = "VERSION", repo_name = "com_google_protobuf")
Add the following to your WORKSPACE file. Note that as of protobuf 30.x, additional load statements are required to properly set up rules_java and rules_python:http_archive(
name = "com_google_protobuf",
strip_prefix = "protobuf-VERSION",
sha256 = ...,
url = ...,
)
load("@com_google_protobuf//:protobuf_deps.bzl", "protobuf_deps")
protobuf_deps()
load("@rules_java//java:rules_java_deps.bzl", "rules_java_dependencies")
rules_java_dependencies()
load("@rules_java//java:repositories.bzl", "rules_java_toolchains")
rules_java_toolchains()
load("@rules_python//python:repositories.bzl", "py_repositories")
py_repositories()
proto_library
proto_library declares a group of .proto source files and their dependencies. It does not generate any language-specific code by itself; language rules depend on it.
load("@protobuf//bazel:proto_library.bzl", "proto_library")
proto_library(
name = "person_proto",
srcs = ["person.proto"],
deps = [
"@protobuf//:timestamp_proto",
],
)
| Attribute | Description |
|---|
srcs | List of .proto source files. |
deps | Other proto_library targets this library imports. |
strip_import_prefix | Strip this prefix from the import paths of the .proto files in this target. |
import_prefix | A prefix to add to the import paths of the .proto files in this target. |
visibility | Standard Bazel visibility. |
cc_proto_library
cc_proto_library generates C++ code from a proto_library target and compiles it into a C++ library.
load("@protobuf//bazel:cc_proto_library.bzl", "cc_proto_library")
load("@rules_cc//cc:defs.bzl", "cc_binary")
cc_proto_library(
name = "person_cc_proto",
deps = [":person_proto"],
)
cc_binary(
name = "main",
srcs = ["main.cc"],
deps = [":person_cc_proto"],
)
java_proto_library
java_proto_library generates Java code from a proto_library and compiles it into a Java library.
load("@protobuf//bazel:java_proto_library.bzl", "java_proto_library")
load("@rules_java//java:defs.bzl", "java_binary")
java_proto_library(
name = "person_java_proto",
deps = [":person_proto"],
)
java_binary(
name = "Main",
srcs = ["Main.java"],
main_class = "com.example.Main",
deps = [":person_java_proto"],
)
py_proto_library
py_proto_library generates Python code from a proto_library and exposes it as a Python library.
load("@protobuf//bazel:py_proto_library.bzl", "py_proto_library")
load("@rules_python//python:defs.bzl", "py_binary")
py_proto_library(
name = "person_py_proto",
deps = [":person_proto"],
)
py_binary(
name = "main",
srcs = ["main.py"],
deps = [":person_py_proto"],
)
Complete BUILD.bazel example
The following example shows a single BUILD.bazel file that defines proto targets for multiple languages:
load("@protobuf//bazel:proto_library.bzl", "proto_library")
load("@protobuf//bazel:cc_proto_library.bzl", "cc_proto_library")
load("@protobuf//bazel:java_proto_library.bzl", "java_proto_library")
load("@protobuf//bazel:py_proto_library.bzl", "py_proto_library")
load("@rules_cc//cc:defs.bzl", "cc_binary")
load("@rules_java//java:defs.bzl", "java_binary")
load("@rules_python//python:defs.bzl", "py_binary")
# The canonical proto definition.
proto_library(
name = "addressbook_proto",
srcs = ["addressbook.proto"],
deps = ["@protobuf//:timestamp_proto"],
)
# C++ target
cc_proto_library(
name = "addressbook_cc_proto",
deps = [":addressbook_proto"],
)
# Java target
java_proto_library(
name = "addressbook_java_proto",
deps = [":addressbook_proto"],
)
# Python target
py_proto_library(
name = "addressbook_py_proto",
deps = [":addressbook_proto"],
)
# An example binary that uses the C++ generated code.
cc_binary(
name = "add_person",
srcs = ["add_person.cc"],
deps = [
":addressbook_cc_proto",
"@abseil-cpp//absl/log",
],
)
Building from source
To build the protoc binary and the C++ runtime directly from the protobuf source tree:
git clone https://github.com/protocolbuffers/protobuf.git
cd protobuf
git submodule update --init --recursive
bazel build :protoc :protobuf
# Install protoc system-wide (Linux/macOS)
cp bazel-bin/protoc /usr/local/bin
Protobuf supports Bzlmod with Bazel 8 and newer. The legacy WORKSPACE system is still supported but will eventually be deprecated by Bazel.