diff --git a/rcl/include/rcl/init_options.h b/rcl/include/rcl/init_options.h
index 1d33a0739..c6ccb5938 100644
--- a/rcl/include/rcl/init_options.h
+++ b/rcl/include/rcl/init_options.h
@@ -127,6 +127,50 @@ RCL_WARN_UNUSED
rcl_ret_t
rcl_init_options_fini(rcl_init_options_t * init_options);
+/// Return the domain_id stored in the init options.
+/**
+ * Get the domain id from the specified rcl_init_options_t object.
+ *
+ *
+ * Attribute | Adherence
+ * ------------------ | -------------
+ * Allocates Memory | No
+ * Thread-Safe | Yes
+ * Uses Atomics | No
+ * Lock-Free | Yes
+ *
+ * \param[in] init_options object from which the domain id should be retrieved.
+ * \param[out] domain_id domain id to be set in init_options object.
+ * \return `RCL_RET_OK` if successful, or
+ * \return `RCL_RET_INVALID_ARGUMENT` if any arguments are invalid.
+ */
+RCL_PUBLIC
+RCL_WARN_UNUSED
+rcl_ret_t
+rcl_init_options_get_domain_id(rcl_init_options_t * init_options, size_t * domain_id);
+
+/// Set a domain id in the init options provided.
+/**
+ * Store the domain id in the specified init_options object.
+ *
+ *
+ * Attribute | Adherence
+ * ------------------ | -------------
+ * Allocates Memory | No
+ * Thread-Safe | Yes
+ * Uses Atomics | No
+ * Lock-Free | Yes
+ *
+ * \param[in] init_options objects in which to set the specified domain id.
+ * \param[in] domain_id domain id to be set in init_options object.
+ * \return `RCL_RET_OK` if successful, or
+ * \return `RCL_RET_INVALID_ARGUMENT` if any arguments are invalid.
+ */
+RCL_PUBLIC
+RCL_WARN_UNUSED
+rcl_ret_t
+rcl_init_options_set_domain_id(rcl_init_options_t * init_options, size_t domain_id);
+
/// Return the rmw init options which are stored internally.
/**
* This function can fail and return `NULL` if:
diff --git a/rcl/src/rcl/init_options.c b/rcl/src/rcl/init_options.c
index ebf5c7b77..272e69184 100644
--- a/rcl/src/rcl/init_options.c
+++ b/rcl/src/rcl/init_options.c
@@ -142,6 +142,25 @@ rcl_init_options_fini(rcl_init_options_t * init_options)
return RCL_RET_OK;
}
+rcl_ret_t
+rcl_init_options_get_domain_id(rcl_init_options_t * init_options, size_t * domain_id)
+{
+ RCL_CHECK_ARGUMENT_FOR_NULL(init_options, RCL_RET_INVALID_ARGUMENT);
+ RCL_CHECK_ARGUMENT_FOR_NULL(init_options->impl, RCL_RET_INVALID_ARGUMENT);
+ RCL_CHECK_ARGUMENT_FOR_NULL(domain_id, RCL_RET_INVALID_ARGUMENT);
+ *domain_id = init_options->impl->rmw_init_options.domain_id;
+ return RCL_RET_OK;
+}
+
+rcl_ret_t
+rcl_init_options_set_domain_id(rcl_init_options_t * init_options, size_t domain_id)
+{
+ RCL_CHECK_ARGUMENT_FOR_NULL(init_options, RCL_RET_INVALID_ARGUMENT);
+ RCL_CHECK_ARGUMENT_FOR_NULL(init_options->impl, RCL_RET_INVALID_ARGUMENT);
+ init_options->impl->rmw_init_options.domain_id = domain_id;
+ return RCL_RET_OK;
+}
+
rmw_init_options_t *
rcl_init_options_get_rmw_init_options(rcl_init_options_t * init_options)
{
diff --git a/rcl/test/rcl/test_init.cpp b/rcl/test/rcl/test_init.cpp
index 2abf6f748..acc7610ad 100644
--- a/rcl/test/rcl/test_init.cpp
+++ b/rcl/test/rcl/test_init.cpp
@@ -453,8 +453,34 @@ TEST_F(CLASSNAME(TestRCLFixture, RMW_IMPLEMENTATION), test_rcl_init_options_acce
const rcl_allocator_t * options_allocator = rcl_init_options_get_allocator(&init_options);
EXPECT_TRUE(rcutils_allocator_is_valid(options_allocator));
+ size_t domain_id;
+ ret = rcl_init_options_get_domain_id(NULL, &domain_id);
+ ASSERT_EQ(RCL_RET_INVALID_ARGUMENT, ret) << rcl_get_error_string().str;
+ rcl_reset_error();
+ ret = rcl_init_options_get_domain_id(&init_options, NULL);
+ ASSERT_EQ(RCL_RET_INVALID_ARGUMENT, ret) << rcl_get_error_string().str;
+ rcl_reset_error();
+ ret = rcl_init_options_get_domain_id(NULL, NULL);
+ ASSERT_EQ(RCL_RET_INVALID_ARGUMENT, ret) << rcl_get_error_string().str;
+ rcl_reset_error();
+ ret = rcl_init_options_set_domain_id(NULL, domain_id);
+ ASSERT_EQ(RCL_RET_INVALID_ARGUMENT, ret) << rcl_get_error_string().str;
+ rcl_reset_error();
+
+ ret = rcl_init_options_get_domain_id(&init_options, &domain_id);
+ ASSERT_EQ(RCL_RET_OK, ret) << rcl_get_error_string().str;
+ EXPECT_EQ(RCL_DEFAULT_DOMAIN_ID, domain_id);
+ ret = rcl_init_options_set_domain_id(&init_options, static_cast(0u));
+ ASSERT_EQ(RCL_RET_OK, ret) << rcl_get_error_string().str;
+ ret = rcl_init_options_get_domain_id(&init_options, &domain_id);
+ ASSERT_EQ(RCL_RET_OK, ret) << rcl_get_error_string().str;
+ EXPECT_EQ(0U, domain_id);
+
rcl_init_options_t init_options_dst = rcl_get_zero_initialized_init_options();
- EXPECT_EQ(RCL_RET_OK, rcl_init_options_copy(&init_options, &init_options_dst));
+ ASSERT_EQ(RCL_RET_OK, rcl_init_options_copy(&init_options, &init_options_dst));
+ ret = rcl_init_options_get_domain_id(&init_options_dst, &domain_id);
+ ASSERT_EQ(RCL_RET_OK, ret) << rcl_get_error_string().str;
+ EXPECT_EQ(0U, domain_id);
EXPECT_EQ(RCL_RET_ALREADY_INIT, rcl_init_options_copy(&init_options, &init_options_dst));
EXPECT_EQ(RCL_RET_OK, rcl_init_options_fini(&init_options_dst));
}