diff --git a/circuits/cpp/cmake/msgpack.cmake b/circuits/cpp/cmake/msgpack.cmake
new file mode 100644
index 00000000000..8ce70891552
--- /dev/null
+++ b/circuits/cpp/cmake/msgpack.cmake
@@ -0,0 +1,16 @@
+include(ExternalProject)
+
+# External project: Download msgpack-c from GitHu
+set(MSGPACK_PREFIX "${CMAKE_BINARY_DIR}/_deps/msgpack-c")
+set(MSGPACK_INCLUDE "${MSGPACK_PREFIX}/src/msgpack-c/include")
+
+ExternalProject_Add(
+    msgpack-c
+    PREFIX ${MSGPACK_PREFIX}
+    GIT_REPOSITORY "https://github.com/AztecProtocol/msgpack-c.git"
+    GIT_TAG af447c28f0bafe761290a72754212436e530941b
+    CONFIGURE_COMMAND ""  # No configure step
+    BUILD_COMMAND ""      # No build step
+    INSTALL_COMMAND ""    # No install step
+    UPDATE_COMMAND ""     # No update step
+)
\ No newline at end of file