diff --git a/rcl/include/rcl/node.h b/rcl/include/rcl/node.h
index 2c8a0a4..945f662 100644
--- a/rcl/include/rcl/node.h
+++ b/rcl/include/rcl/node.h
@@ -44,9 +44,12 @@ typedef struct rcl_node_t
 typedef struct rcl_node_options_t
 {
   // bool anonymous_name;
+
   // rmw_qos_profile_t parameter_qos;
+
   /// If true, no parameter infrastructure will be setup.
   // bool no_parameters;
+
   /// If set, then this value overrides the ROS_DOMAIN_ID environment variable.
   /**
    * It defaults to RCL_NODE_OPTIONS_DEFAULT_DOMAIN_ID, which will cause the
@@ -59,6 +62,7 @@ typedef struct rcl_node_options_t
    *   (currently max size_t)
    */
   size_t domain_id;
+
   /// Custom allocator used for internal allocations.
   rcl_allocator_t allocator;
 } rcl_node_options_t;
@@ -77,11 +81,27 @@ rcl_get_zero_initialized_node(void);
  * After calling, the ROS node object can be used to create other middleware
  * primitives like publishers, services, parameters, etc.
  *
+ * The name of the node must not be NULL and adhere to naming restrictions,
+ * see the rmw_validate_node_name() function for rules.
+ *
  * \todo TODO(wjwwood): node name uniqueness is no yet enforced
  *
  * The name of the node cannot coincide with another node of the same name.
  * If a node of the same name is already in the domain, it will be shutdown.
  *
+ * The namespace of the node should not be NULL and should also pass the
+ * rmw_validate_namespace() function's rules.
+ *
+ * Additionally this function allows namespaces which lack a leading forward
+ * slash.
+ * Because there is no notion of a relative namespace, there is no difference
+ * between a namespace which lacks a forward and the same namespace with a
+ * leasing forward slash.
+ * Therefore, a namespace like ``"foo/bar"`` is automatically changed to
+ * ``"/foo/bar"`` by this function.
+ * Similarly, the namespace ``""`` will implicitly become ``"/"`` which is a
+ * valid namespace.
+ *
  * \todo TODO(wjwwood):
  *   Parameter infrastructure is currently initialized in the language specific
  *   client library, e.g. rclcpp for C++, but will be initialized here in the
@@ -104,7 +124,7 @@ rcl_get_zero_initialized_node(void);
  * rcl_node_t node = rcl_get_zero_initialized_node();
  * rcl_node_options_t * node_ops = rcl_node_get_default_options();
  * // ... node options customization
- * rcl_ret_t ret = rcl_node_init(&node, "node_name", node_ops);
+ * rcl_ret_t ret = rcl_node_init(&node, "node_name", "/node_ns", node_ops);
  * // ... error handling and then use the node, but eventually deinitialize it:
  * ret = rcl_node_fini(&node);
  * // ... error handling for rcl_node_fini()
@@ -123,18 +143,25 @@ rcl_get_zero_initialized_node(void);
  * \post the node handle is valid and can be used in other `rcl_*` functions
  *
  * \param[inout] node a preallocated rcl_node_t
- * \param[in] name the name of the node
+ * \param[in] name the name of the node, must be a valid c-string
+ * \param[in] namespace_ the namespace of the node, must be a valid c-string
  * \param[in] options the node options
  * \return `RCL_RET_OK` if the node was initialized successfully, or
  * \return `RCL_RET_ALREADY_INIT` if the node has already be initialized, or
  * \return `RCL_RET_INVALID_ARGUMENT` if any arguments are invalid, or
  * \return `RCL_RET_BAD_ALLOC` if allocating memory failed, or
+ * \return `RCL_RET_NODE_INVALID_NAME` if the name is invalid, or
+ * \return `RCL_RET_NODE_INVALID_NAMESPACE` if the namespace_ is invalid, or
  * \return `RCL_RET_ERROR` if an unspecified error occurs.
  */
 RCL_PUBLIC
 RCL_WARN_UNUSED
 rcl_ret_t
-rcl_node_init(rcl_node_t * node, const char * name, const rcl_node_options_t * options);
+rcl_node_init(
+  rcl_node_t * node,
+  const char * name,
+  const char * namespace_,
+  const rcl_node_options_t * options);
 
 /// Finalized a rcl_node_t.
 /**
@@ -240,6 +267,33 @@ RCL_WARN_UNUSED
 const char *
 rcl_node_get_name(const rcl_node_t * node);
 
+/// Return the namespace of the node.
+/**
+ * This function returns the node's internal namespace string.
+ * This function can fail, and therefore return `NULL`, if:
+ *   - node is `NULL`
+ *   - node has not been initialized (the implementation is invalid)
+ *
+ * The returned string is only valid as long as the given rcl_node_t is valid.
+ * The value of the string may change if the value in the rcl_node_t changes,
+ * and therefore copying the string is recommended if this is a concern.
+ *
+ * <hr>
+ * Attribute          | Adherence
+ * ------------------ | -------------
+ * Allocates Memory   | No
+ * Thread-Safe        | No
+ * Uses Atomics       | No
+ * Lock-Free          | Yes
+ *
+ * \param[in] node pointer to the node
+ * \return name string if successful, otherwise `NULL`
+ */
+RCL_PUBLIC
+RCL_WARN_UNUSED
+const char *
+rcl_node_get_namespace(const rcl_node_t * node);
+
 /// Return the rcl node options.
 /**
  * This function returns the node's internal options struct.
diff --git a/rcl/include/rcl/types.h b/rcl/include/rcl/types.h
index bf6bdc4..9062c1b 100644
--- a/rcl/include/rcl/types.h
+++ b/rcl/include/rcl/types.h
@@ -24,22 +24,24 @@ typedef rmw_ret_t rcl_ret_t;
 #define RCL_RET_ERROR RMW_RET_ERROR
 /// Timeout occurred return code.
 #define RCL_RET_TIMEOUT RMW_RET_TIMEOUT
+/// Failed to allocate memory return code.
+#define RCL_RET_BAD_ALLOC RMW_RET_BAD_ALLOC
+/// Invalid argument return code.
+#define RCL_RET_INVALID_ARGUMENT RMW_RET_INVALID_ARGUMENT
 
 // rcl specific ret codes start at 100
 /// rcl_init() already called return code.
 #define RCL_RET_ALREADY_INIT 100
 /// rcl_init() not yet called return code.
 #define RCL_RET_NOT_INIT 101
-/// Failed to allocate memory return code.
-#define RCL_RET_BAD_ALLOC 102
-/// Invalid argument return code.
-#define RCL_RET_INVALID_ARGUMENT 103
 /// Mismatched rmw identifier return code.
-#define RCL_RET_MISMATCHED_RMW_ID 104
+#define RCL_RET_MISMATCHED_RMW_ID 102
 
 // rcl node specific ret codes in 2XX
 /// Invalid rcl_node_t given return code.
 #define RCL_RET_NODE_INVALID 200
+#define RCL_RET_NODE_INVALID_NAME 201
+#define RCL_RET_NODE_INVALID_NAMESPACE 202
 
 // rcl publisher specific ret codes in 3XX
 /// Invalid rcl_publisher_t given return code.
diff --git a/rcl/src/rcl/node.c b/rcl/src/rcl/node.c
index e987f0c..aa3d5e2 100644
--- a/rcl/src/rcl/node.c
+++ b/rcl/src/rcl/node.c
@@ -26,9 +26,19 @@ extern "C"
 
 #include "rcl/rcl.h"
 #include "rmw/rmw.h"
+#include "rmw/validate_namespace.h"
+#include "rmw/validate_node_name.h"
+#include "rmw/validate_topic_name.h"
 
 #include "./common.h"
 
+#ifndef _WIN32
+  #define LOCAL_SNPRINTF snprintf
+#else
+  #define LOCAL_SNPRINTF(buffer, buffer_size, format, ...) \
+  _snprintf_s(buffer, buffer_size, _TRUNCATE, format, __VA_ARGS__)
+#endif
+
 typedef struct rcl_node_impl_t
 {
   rcl_node_options_t options;
@@ -46,7 +56,11 @@ rcl_get_zero_initialized_node()
 }
 
 rcl_ret_t
-rcl_node_init(rcl_node_t * node, const char * name, const rcl_node_options_t * options)
+rcl_node_init(
+  rcl_node_t * node,
+  const char * name,
+  const char * namespace_,
+  const rcl_node_options_t * options)
 {
   size_t domain_id = 0;
   const char * ros_domain_id;
@@ -56,6 +70,7 @@ rcl_node_init(rcl_node_t * node, const char * name, const rcl_node_options_t * o
   rcl_ret_t ret;
   rcl_ret_t fail_ret = RCL_RET_ERROR;
   RCL_CHECK_ARGUMENT_FOR_NULL(name, RCL_RET_INVALID_ARGUMENT);
+  RCL_CHECK_ARGUMENT_FOR_NULL(namespace_, RCL_RET_INVALID_ARGUMENT);
   RCL_CHECK_ARGUMENT_FOR_NULL(options, RCL_RET_INVALID_ARGUMENT);
   RCL_CHECK_ARGUMENT_FOR_NULL(node, RCL_RET_INVALID_ARGUMENT);
   if (node->impl) {
@@ -72,18 +87,69 @@ rcl_node_init(rcl_node_t * node, const char * name, const rcl_node_options_t * o
     allocator->allocate, "allocate not set", return RCL_RET_INVALID_ARGUMENT);
   RCL_CHECK_FOR_NULL_WITH_MSG(
     allocator->deallocate, "deallocate not set", return RCL_RET_INVALID_ARGUMENT);
+  // Make sure the node name is valid before allocating memory.
+  int validation_result = 0;
+  ret = rmw_validate_node_name(name, &validation_result, NULL);
+  if (ret != RMW_RET_OK) {
+    RCL_SET_ERROR_MSG(rmw_get_error_string_safe());
+    return ret;
+  }
+  if (validation_result != RMW_NODE_NAME_VALID) {
+    const char * msg = rmw_node_name_validation_result_string(validation_result);
+    if (!msg) {
+      msg = "unknown validation_result, this should not happen";
+    }
+    RCL_SET_ERROR_MSG(msg);
+    return RCL_RET_NODE_INVALID_NAME;
+  }
+
+  // Process the namespace.
+  size_t namespace_length = strlen(namespace_);
+  const char * local_namespace_ = namespace_;
+  bool should_free_local_namespace_ = false;
+  // If the namespace is just an empty string, replace with "/"
+  if (namespace_length == 0) {
+    // Have this special case to avoid a memory allocation when "" is passed.
+    local_namespace_ = "/";
+  }
+  // If the namespace does not start with a /, add one.
+  if (namespace_length > 0 && namespace_[0] != '/') {
+    // TODO(wjwwood): replace with generic strcat that takes an allocator once available
+    // length + 2, because new leading / and terminating \0
+    char * temp = (char *)allocator->allocate(namespace_length + 2, allocator->state);
+    RCL_CHECK_FOR_NULL_WITH_MSG(temp, "allocating memory failed", return RCL_RET_BAD_ALLOC);
+    temp[0] = '/';
+    memcpy(temp + 1, namespace_, strlen(namespace_) + 1);
+    local_namespace_ = temp;
+    should_free_local_namespace_ = true;
+  }
+  // Make sure the node namespace is valid.
+  validation_result = 0;
+  ret = rmw_validate_namespace(local_namespace_, &validation_result, NULL);
+  if (ret != RMW_RET_OK) {
+    RCL_SET_ERROR_MSG(rmw_get_error_string_safe());
+    return ret;
+  }
+  if (validation_result != RMW_NAMESPACE_VALID) {
+    const char * msg = rmw_namespace_validation_result_string(validation_result);
+    if (!msg) {
+      char fixed_msg[256];
+      LOCAL_SNPRINTF(
+        fixed_msg, sizeof(fixed_msg),
+        "unknown validation_result '%d', this should not happen", validation_result);
+      RCL_SET_ERROR_MSG(fixed_msg);
+    } else {
+      RCL_SET_ERROR_MSG(msg);
+    }
+    return RCL_RET_NODE_INVALID_NAMESPACE;
+  }
+
   // Allocate space for the implementation struct.
   node->impl = (rcl_node_impl_t *)allocator->allocate(sizeof(rcl_node_impl_t), allocator->state);
   RCL_CHECK_FOR_NULL_WITH_MSG(node->impl, "allocating memory failed", return RCL_RET_BAD_ALLOC);
   node->impl->rmw_node_handle = NULL;
   node->impl->graph_guard_condition = NULL;
   // Initialize node impl.
-  // node name
-  size_t name_len = strlen(name);
-  if (name_len == 0) {
-    RCL_SET_ERROR_MSG("node name cannot be empty string");
-    goto fail;
-  }
   // node options (assume it is trivially copyable)
   node->impl->options = *options;
   // node rmw_node_handle
@@ -106,9 +172,13 @@ rcl_node_init(rcl_node_t * node, const char * name, const rcl_node_options_t * o
   }
   // actual domain id
   node->impl->actual_domain_id = domain_id;
-  node->impl->rmw_node_handle = rmw_create_node(name, domain_id);
+  node->impl->rmw_node_handle = rmw_create_node(name, local_namespace_, domain_id);
   RCL_CHECK_FOR_NULL_WITH_MSG(
     node->impl->rmw_node_handle, rmw_get_error_string_safe(), goto fail);
+  // free local_namespace_ if necessary
+  if (should_free_local_namespace_) {
+    allocator->deallocate((char *)local_namespace_, allocator->state);
+  }
   // instance id
   node->impl->rcl_instance_id = rcl_get_instance_id();
   // graph guard condition
@@ -215,6 +285,15 @@ rcl_node_get_name(const rcl_node_t * node)
   return node->impl->rmw_node_handle->name;
 }
 
+const char *
+rcl_node_get_namespace(const rcl_node_t * node)
+{
+  if (!rcl_node_is_valid(node)) {
+    return NULL;
+  }
+  return node->impl->rmw_node_handle->namespace_;
+}
+
 const rcl_node_options_t *
 rcl_node_get_options(const rcl_node_t * node)
 {
diff --git a/rcl/test/rcl/client_fixture.cpp b/rcl/test/rcl/client_fixture.cpp
index d718565..f43dcad 100644
--- a/rcl/test/rcl/client_fixture.cpp
+++ b/rcl/test/rcl/client_fixture.cpp
@@ -109,7 +109,7 @@ int main(int argc, char ** argv)
     rcl_node_t node = rcl_get_zero_initialized_node();
     const char * name = "node_name";
     rcl_node_options_t node_options = rcl_node_get_default_options();
-    if (rcl_node_init(&node, name, &node_options) != RCL_RET_OK) {
+    if (rcl_node_init(&node, name, "", &node_options) != RCL_RET_OK) {
       fprintf(stderr, "Error in node init: %s\n", rcl_get_error_string_safe());
       return -1;
     }
diff --git a/rcl/test/rcl/service_fixture.cpp b/rcl/test/rcl/service_fixture.cpp
index 3fe2baf..0d01fdd 100644
--- a/rcl/test/rcl/service_fixture.cpp
+++ b/rcl/test/rcl/service_fixture.cpp
@@ -83,7 +83,7 @@ int main(int argc, char ** argv)
     rcl_node_t node = rcl_get_zero_initialized_node();
     const char * name = "node_name";
     rcl_node_options_t node_options = rcl_node_get_default_options();
-    if (rcl_node_init(&node, name, &node_options) != RCL_RET_OK) {
+    if (rcl_node_init(&node, name, "", &node_options) != RCL_RET_OK) {
       fprintf(stderr, "Error in node init: %s\n", rcl_get_error_string_safe());
       return -1;
     }
diff --git a/rcl/test/rcl/test_client.cpp b/rcl/test/rcl/test_client.cpp
index 643dd93..087d44a 100644
--- a/rcl/test/rcl/test_client.cpp
+++ b/rcl/test/rcl/test_client.cpp
@@ -39,7 +39,7 @@ public:
     *this->node_ptr = rcl_get_zero_initialized_node();
     const char * name = "node_name";
     rcl_node_options_t node_options = rcl_node_get_default_options();
-    ret = rcl_node_init(this->node_ptr, name, &node_options);
+    ret = rcl_node_init(this->node_ptr, name, "", &node_options);
     ASSERT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
     set_on_unexpected_malloc_callback([]() {ASSERT_FALSE(true) << "UNEXPECTED MALLOC";});
     set_on_unexpected_realloc_callback([]() {ASSERT_FALSE(true) << "UNEXPECTED REALLOC";});
diff --git a/rcl/test/rcl/test_get_node_names.cpp b/rcl/test/rcl/test_get_node_names.cpp
index 536e14c..463b31f 100644
--- a/rcl/test/rcl/test_get_node_names.cpp
+++ b/rcl/test/rcl/test_get_node_names.cpp
@@ -63,14 +63,14 @@ TEST_F(CLASSNAME(TestGetNodeNames, RMW_IMPLEMENTATION), test_rcl_get_node_names)
   *node1_ptr = rcl_get_zero_initialized_node();
   const char * node1_name = "node1";
   rcl_node_options_t node1_options = rcl_node_get_default_options();
-  ret = rcl_node_init(node1_ptr, node1_name, &node1_options);
+  ret = rcl_node_init(node1_ptr, node1_name, "", &node1_options);
   ASSERT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
 
   auto node2_ptr = new rcl_node_t;
   *node2_ptr = rcl_get_zero_initialized_node();
   const char * node2_name = "node2";
   rcl_node_options_t node2_options = rcl_node_get_default_options();
-  ret = rcl_node_init(node2_ptr, node2_name, &node2_options);
+  ret = rcl_node_init(node2_ptr, node2_name, "", &node2_options);
   ASSERT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
 
   std::this_thread::sleep_for(1s);
diff --git a/rcl/test/rcl/test_graph.cpp b/rcl/test/rcl/test_graph.cpp
index fe14817..97777da 100644
--- a/rcl/test/rcl/test_graph.cpp
+++ b/rcl/test/rcl/test_graph.cpp
@@ -63,7 +63,7 @@ public:
     *this->old_node_ptr = rcl_get_zero_initialized_node();
     const char * old_name = "old_node_name";
     rcl_node_options_t node_options = rcl_node_get_default_options();
-    ret = rcl_node_init(this->old_node_ptr, old_name, &node_options);
+    ret = rcl_node_init(this->old_node_ptr, old_name, "", &node_options);
     ASSERT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
     ret = rcl_shutdown();  // after this, the old_node_ptr should be invalid
     EXPECT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
@@ -73,7 +73,7 @@ public:
     this->node_ptr = new rcl_node_t;
     *this->node_ptr = rcl_get_zero_initialized_node();
     const char * name = "node_name";
-    ret = rcl_node_init(this->node_ptr, name, &node_options);
+    ret = rcl_node_init(this->node_ptr, name, "", &node_options);
     ASSERT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
 
     this->wait_set_ptr = new rcl_wait_set_t;
diff --git a/rcl/test/rcl/test_node.cpp b/rcl/test/rcl/test_node.cpp
index de7909d..27ed3cd 100644
--- a/rcl/test/rcl/test_node.cpp
+++ b/rcl/test/rcl/test_node.cpp
@@ -73,15 +73,16 @@ TEST_F(CLASSNAME(TestNodeFixture, RMW_IMPLEMENTATION), test_rcl_node_accessors)
   // Create an invalid node (rcl_shutdown).
   rcl_node_t invalid_node = rcl_get_zero_initialized_node();
   const char * name = "node_name";
+  const char * namespace_ = "/ns";
   rcl_node_options_t default_options = rcl_node_get_default_options();
   default_options.domain_id = 42;  // Set the domain id to something explicit.
-  ret = rcl_node_init(&invalid_node, name, &default_options);
+  ret = rcl_node_init(&invalid_node, name, namespace_, &default_options);
   if (is_windows && is_opensplice) {
     // On Windows with OpenSplice, setting the domain id is not expected to work.
     ASSERT_NE(RCL_RET_OK, ret);
     // So retry with the default domain id setting (uses the environment as is).
     default_options.domain_id = rcl_node_get_default_options().domain_id;
-    ret = rcl_node_init(&invalid_node, name, &default_options);
+    ret = rcl_node_init(&invalid_node, name, namespace_, &default_options);
     ASSERT_EQ(RCL_RET_OK, ret);
   } else {
     // This is the normal check (not windows and windows if not opensplice)
@@ -105,7 +106,7 @@ TEST_F(CLASSNAME(TestNodeFixture, RMW_IMPLEMENTATION), test_rcl_node_accessors)
   rcl_node_t zero_node = rcl_get_zero_initialized_node();
   // Create a normal node.
   rcl_node_t node = rcl_get_zero_initialized_node();
-  ret = rcl_node_init(&node, name, &default_options);
+  ret = rcl_node_init(&node, name, namespace_, &default_options);
   ASSERT_EQ(RCL_RET_OK, ret);
   auto rcl_node_exit = make_scope_exit([&node]() {
     stop_memory_checking();
@@ -150,6 +151,30 @@ TEST_F(CLASSNAME(TestNodeFixture, RMW_IMPLEMENTATION), test_rcl_node_accessors)
   if (actual_node_name) {
     EXPECT_EQ(std::string(name), std::string(actual_node_name));
   }
+  // Test rcl_node_get_namespace().
+  const char * actual_node_namespace;
+  actual_node_namespace = rcl_node_get_namespace(nullptr);
+  EXPECT_EQ(nullptr, actual_node_namespace);
+  rcl_reset_error();
+  actual_node_namespace = rcl_node_get_namespace(&zero_node);
+  EXPECT_EQ(nullptr, actual_node_namespace);
+  rcl_reset_error();
+  actual_node_namespace = rcl_node_get_namespace(&invalid_node);
+  EXPECT_EQ(nullptr, actual_node_namespace);
+  rcl_reset_error();
+  start_memory_checking();
+  assert_no_malloc_begin();
+  assert_no_realloc_begin();
+  assert_no_free_begin();
+  actual_node_namespace = rcl_node_get_namespace(&node);
+  assert_no_malloc_end();
+  assert_no_realloc_end();
+  assert_no_free_end();
+  stop_memory_checking();
+  EXPECT_TRUE(actual_node_namespace ? true : false);
+  if (actual_node_namespace) {
+    EXPECT_EQ(std::string(namespace_), std::string(actual_node_namespace));
+  }
   // Test rcl_node_get_options().
   const rcl_node_options_t * actual_options;
   actual_options = rcl_node_get_options(nullptr);
@@ -179,12 +204,15 @@ TEST_F(CLASSNAME(TestNodeFixture, RMW_IMPLEMENTATION), test_rcl_node_accessors)
   size_t actual_domain_id;
   ret = rcl_node_get_domain_id(nullptr, &actual_domain_id);
   EXPECT_EQ(RCL_RET_INVALID_ARGUMENT, ret);
+  ASSERT_TRUE(rcl_error_is_set());
   rcl_reset_error();
   ret = rcl_node_get_domain_id(&zero_node, &actual_domain_id);
   EXPECT_EQ(RCL_RET_NODE_INVALID, ret);
+  ASSERT_TRUE(rcl_error_is_set());
   rcl_reset_error();
   ret = rcl_node_get_domain_id(&invalid_node, &actual_domain_id);
   EXPECT_EQ(RCL_RET_NODE_INVALID, ret);
+  ASSERT_TRUE(rcl_error_is_set());
   rcl_reset_error();
   start_memory_checking();
   assert_no_malloc_begin();
@@ -278,10 +306,12 @@ TEST_F(CLASSNAME(TestNodeFixture, RMW_IMPLEMENTATION), test_rcl_node_life_cycle)
   rcl_ret_t ret;
   rcl_node_t node = rcl_get_zero_initialized_node();
   const char * name = "node_name";
+  const char * namespace_ = "/ns";
   rcl_node_options_t default_options = rcl_node_get_default_options();
   // Trying to init before rcl_init() should fail.
-  ret = rcl_node_init(&node, name, &default_options);
+  ret = rcl_node_init(&node, name, "", &default_options);
   ASSERT_EQ(RCL_RET_NOT_INIT, ret) << "Expected RCL_RET_NOT_INIT";
+  ASSERT_TRUE(rcl_error_is_set());
   rcl_reset_error();
   // Initialize rcl with rcl_init().
   ret = rcl_init(0, nullptr, rcl_get_default_allocator());
@@ -291,48 +321,60 @@ TEST_F(CLASSNAME(TestNodeFixture, RMW_IMPLEMENTATION), test_rcl_node_life_cycle)
     ASSERT_EQ(RCL_RET_OK, ret);
   });
   // Try invalid arguments.
-  ret = rcl_node_init(nullptr, name, &default_options);
+  ret = rcl_node_init(nullptr, name, namespace_, &default_options);
   EXPECT_EQ(RCL_RET_INVALID_ARGUMENT, ret);
+  ASSERT_TRUE(rcl_error_is_set());
   rcl_reset_error();
-  ret = rcl_node_init(&node, nullptr, &default_options);
+  ret = rcl_node_init(&node, nullptr, namespace_, &default_options);
   EXPECT_EQ(RCL_RET_INVALID_ARGUMENT, ret);
+  ASSERT_TRUE(rcl_error_is_set());
   rcl_reset_error();
-  ret = rcl_node_init(&node, name, nullptr);
+  ret = rcl_node_init(&node, name, nullptr, &default_options);
   EXPECT_EQ(RCL_RET_INVALID_ARGUMENT, ret);
+  ASSERT_TRUE(rcl_error_is_set());
+  rcl_reset_error();
+  ret = rcl_node_init(&node, name, namespace_, nullptr);
+  EXPECT_EQ(RCL_RET_INVALID_ARGUMENT, ret);
+  ASSERT_TRUE(rcl_error_is_set());
   rcl_reset_error();
   // Try with invalid allocator.
   rcl_node_options_t options_with_invalid_allocator = rcl_node_get_default_options();
   options_with_invalid_allocator.allocator.allocate = nullptr;
   options_with_invalid_allocator.allocator.deallocate = nullptr;
   options_with_invalid_allocator.allocator.reallocate = nullptr;
-  ret = rcl_node_init(&node, name, &options_with_invalid_allocator);
+  ret = rcl_node_init(&node, name, namespace_, &options_with_invalid_allocator);
   EXPECT_EQ(RCL_RET_INVALID_ARGUMENT, ret) << "Expected RCL_RET_INVALID_ARGUMENT";
+  ASSERT_TRUE(rcl_error_is_set());
   rcl_reset_error();
   // Try with failing allocator.
   rcl_node_options_t options_with_failing_allocator = rcl_node_get_default_options();
   options_with_failing_allocator.allocator.allocate = failing_malloc;
   options_with_failing_allocator.allocator.deallocate = failing_free;
   options_with_failing_allocator.allocator.reallocate = failing_realloc;
-  ret = rcl_node_init(&node, name, &options_with_failing_allocator);
+  ret = rcl_node_init(&node, name, namespace_, &options_with_failing_allocator);
   EXPECT_EQ(RCL_RET_BAD_ALLOC, ret) << "Expected RCL_RET_BAD_ALLOC";
+  ASSERT_TRUE(rcl_error_is_set());
   rcl_reset_error();
   // Try fini with invalid arguments.
   ret = rcl_node_fini(nullptr);
   EXPECT_EQ(RCL_RET_INVALID_ARGUMENT, ret) << "Expected RCL_RET_INVALID_ARGUMENT";
+  ASSERT_TRUE(rcl_error_is_set());
   rcl_reset_error();
   // Try fini with an uninitialized node.
   ret = rcl_node_fini(&node);
   EXPECT_EQ(RCL_RET_OK, ret);
   // Try a normal init and fini.
-  ret = rcl_node_init(&node, name, &default_options);
+  ret = rcl_node_init(&node, name, namespace_, &default_options);
   EXPECT_EQ(RCL_RET_OK, ret);
   ret = rcl_node_fini(&node);
   EXPECT_EQ(RCL_RET_OK, ret);
   // Try repeated init and fini calls.
-  ret = rcl_node_init(&node, name, &default_options);
+  ret = rcl_node_init(&node, name, namespace_, &default_options);
   EXPECT_EQ(RCL_RET_OK, ret);
-  ret = rcl_node_init(&node, name, &default_options);
+  ret = rcl_node_init(&node, name, namespace_, &default_options);
   EXPECT_EQ(RCL_RET_ALREADY_INIT, ret) << "Expected RCL_RET_ALREADY_INIT";
+  ASSERT_TRUE(rcl_error_is_set());
+  rcl_reset_error();
   ret = rcl_node_fini(&node);
   EXPECT_EQ(RCL_RET_OK, ret);
   ret = rcl_node_fini(&node);
@@ -340,7 +382,7 @@ TEST_F(CLASSNAME(TestNodeFixture, RMW_IMPLEMENTATION), test_rcl_node_life_cycle)
   // Try with a specific domain id.
   rcl_node_options_t options_with_custom_domain_id = rcl_node_get_default_options();
   options_with_custom_domain_id.domain_id = 42;
-  ret = rcl_node_init(&node, name, &options_with_custom_domain_id);
+  ret = rcl_node_init(&node, name, namespace_, &options_with_custom_domain_id);
   if (is_windows && is_opensplice) {
     // A custom domain id is not expected to work on Windows with Opensplice.
     EXPECT_NE(RCL_RET_OK, ret);
@@ -351,3 +393,161 @@ TEST_F(CLASSNAME(TestNodeFixture, RMW_IMPLEMENTATION), test_rcl_node_life_cycle)
     EXPECT_EQ(RCL_RET_OK, ret);
   }
 }
+
+/* Tests the node name restrictions enforcement.
+ */
+TEST_F(CLASSNAME(TestNodeFixture, RMW_IMPLEMENTATION), test_rcl_node_name_restrictions) {
+  stop_memory_checking();
+  rcl_ret_t ret;
+
+  // Initialize rcl with rcl_init().
+  ret = rcl_init(0, nullptr, rcl_get_default_allocator());
+  ASSERT_EQ(RCL_RET_OK, ret);
+  auto rcl_shutdown_exit = make_scope_exit([]() {
+    rcl_ret_t ret = rcl_shutdown();
+    ASSERT_EQ(RCL_RET_OK, ret);
+  });
+
+  const char * namespace_ = "/ns";
+  rcl_node_options_t default_options = rcl_node_get_default_options();
+
+  // First do a normal node name.
+  {
+    rcl_node_t node = rcl_get_zero_initialized_node();
+    ret = rcl_node_init(&node, "my_node_42", namespace_, &default_options);
+    ASSERT_EQ(RCL_RET_OK, ret);
+    rcl_ret_t ret = rcl_node_fini(&node);
+    EXPECT_EQ(RCL_RET_OK, ret);
+  }
+
+  // Node name with invalid characters.
+  {
+    rcl_node_t node = rcl_get_zero_initialized_node();
+    ret = rcl_node_init(&node, "my_node_42$", namespace_, &default_options);
+    ASSERT_EQ(RCL_RET_NODE_INVALID_NAME, ret);
+    ASSERT_TRUE(rcl_error_is_set());
+    rcl_reset_error();
+    rcl_ret_t ret = rcl_node_fini(&node);
+    EXPECT_EQ(RCL_RET_OK, ret);
+  }
+
+  // Node name with /, which is valid in a topic, but not a node name.
+  {
+    rcl_node_t node = rcl_get_zero_initialized_node();
+    ret = rcl_node_init(&node, "my/node_42", namespace_, &default_options);
+    ASSERT_EQ(RCL_RET_NODE_INVALID_NAME, ret);
+    ASSERT_TRUE(rcl_error_is_set());
+    rcl_reset_error();
+    rcl_ret_t ret = rcl_node_fini(&node);
+    EXPECT_EQ(RCL_RET_OK, ret);
+  }
+
+  // Node name with {}, which is valid in a topic, but not a node name.
+  {
+    rcl_node_t node = rcl_get_zero_initialized_node();
+    ret = rcl_node_init(&node, "my_{node}_42", namespace_, &default_options);
+    ASSERT_EQ(RCL_RET_NODE_INVALID_NAME, ret);
+    ASSERT_TRUE(rcl_error_is_set());
+    rcl_reset_error();
+    rcl_ret_t ret = rcl_node_fini(&node);
+    EXPECT_EQ(RCL_RET_OK, ret);
+  }
+}
+
+/* Tests the node namespace restrictions enforcement.
+ */
+TEST_F(CLASSNAME(TestNodeFixture, RMW_IMPLEMENTATION), test_rcl_node_namespace_restrictions) {
+  stop_memory_checking();
+  rcl_ret_t ret;
+
+  // Initialize rcl with rcl_init().
+  ret = rcl_init(0, nullptr, rcl_get_default_allocator());
+  ASSERT_EQ(RCL_RET_OK, ret);
+  auto rcl_shutdown_exit = make_scope_exit([]() {
+    rcl_ret_t ret = rcl_shutdown();
+    ASSERT_EQ(RCL_RET_OK, ret);
+  });
+
+  const char * name = "node";
+  rcl_node_options_t default_options = rcl_node_get_default_options();
+
+  // First do a normal node namespace.
+  {
+    rcl_node_t node = rcl_get_zero_initialized_node();
+    ret = rcl_node_init(&node, name, "/ns", &default_options);
+    ASSERT_EQ(RCL_RET_OK, ret);
+    rcl_ret_t ret = rcl_node_fini(&node);
+    EXPECT_EQ(RCL_RET_OK, ret);
+  }
+
+  // Node namespace which is an empty string, which is also valid.
+  {
+    rcl_node_t node = rcl_get_zero_initialized_node();
+    ret = rcl_node_init(&node, name, "", &default_options);
+    ASSERT_EQ(RCL_RET_OK, ret);
+    ASSERT_STREQ("/", rcl_node_get_namespace(&node));
+    rcl_ret_t ret = rcl_node_fini(&node);
+    EXPECT_EQ(RCL_RET_OK, ret);
+  }
+
+  // Node namespace which is just a forward slash, which is valid.
+  {
+    rcl_node_t node = rcl_get_zero_initialized_node();
+    ret = rcl_node_init(&node, name, "/", &default_options);
+    ASSERT_EQ(RCL_RET_OK, ret);
+    rcl_ret_t ret = rcl_node_fini(&node);
+    EXPECT_EQ(RCL_RET_OK, ret);
+  }
+
+  // Node namespaces with invalid characters.
+  {
+    rcl_node_t node = rcl_get_zero_initialized_node();
+    ret = rcl_node_init(&node, name, "/ns/{name}", &default_options);
+    ASSERT_EQ(RCL_RET_NODE_INVALID_NAMESPACE, ret);
+    ASSERT_TRUE(rcl_error_is_set());
+    rcl_reset_error();
+    rcl_ret_t ret = rcl_node_fini(&node);
+    EXPECT_EQ(RCL_RET_OK, ret);
+  }
+  {
+    rcl_node_t node = rcl_get_zero_initialized_node();
+    ret = rcl_node_init(&node, name, "/~/", &default_options);
+    ASSERT_EQ(RCL_RET_NODE_INVALID_NAMESPACE, ret);
+    ASSERT_TRUE(rcl_error_is_set());
+    rcl_reset_error();
+    rcl_ret_t ret = rcl_node_fini(&node);
+    EXPECT_EQ(RCL_RET_OK, ret);
+  }
+
+  // Node namespace with a trailing / which is not allowed.
+  {
+    rcl_node_t node = rcl_get_zero_initialized_node();
+    ret = rcl_node_init(&node, name, "/ns/foo/", &default_options);
+    ASSERT_EQ(RCL_RET_NODE_INVALID_NAMESPACE, ret);
+    ASSERT_TRUE(rcl_error_is_set());
+    rcl_reset_error();
+    rcl_ret_t ret = rcl_node_fini(&node);
+    EXPECT_EQ(RCL_RET_OK, ret);
+  }
+
+  // Node namespace which is not absolute, it should get / added automatically.
+  {
+    rcl_node_t node = rcl_get_zero_initialized_node();
+    ret = rcl_node_init(&node, name, "ns", &default_options);
+    ASSERT_EQ(RCL_RET_OK, ret);
+    ASSERT_STREQ("/ns", rcl_node_get_namespace(&node));
+    rcl_ret_t ret = rcl_node_fini(&node);
+    EXPECT_EQ(RCL_RET_OK, ret);
+  }
+
+  // Other reasons for being invalid, which are related to being part of a topic.
+  {
+    rcl_node_t node = rcl_get_zero_initialized_node();
+    ret = rcl_node_init(&node, name, "/starts/with/42number", &default_options);
+    ASSERT_EQ(RCL_RET_NODE_INVALID_NAMESPACE, ret);
+    ASSERT_TRUE(rcl_error_is_set());
+    rcl_reset_error();
+    rcl_ret_t ret = rcl_node_fini(&node);
+    EXPECT_EQ(RCL_RET_OK, ret);
+  }
+}
diff --git a/rcl/test/rcl/test_publisher.cpp b/rcl/test/rcl/test_publisher.cpp
index d296330..788c1e1 100644
--- a/rcl/test/rcl/test_publisher.cpp
+++ b/rcl/test/rcl/test_publisher.cpp
@@ -46,7 +46,7 @@ public:
     *this->node_ptr = rcl_get_zero_initialized_node();
     const char * name = "node_name";
     rcl_node_options_t node_options = rcl_node_get_default_options();
-    ret = rcl_node_init(this->node_ptr, name, &node_options);
+    ret = rcl_node_init(this->node_ptr, name, "", &node_options);
     ASSERT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
     set_on_unexpected_malloc_callback([]() {ASSERT_FALSE(true) << "UNEXPECTED MALLOC";});
     set_on_unexpected_realloc_callback([]() {ASSERT_FALSE(true) << "UNEXPECTED REALLOC";});
diff --git a/rcl/test/rcl/test_service.cpp b/rcl/test/rcl/test_service.cpp
index 4e63019..96cb6ed 100644
--- a/rcl/test/rcl/test_service.cpp
+++ b/rcl/test/rcl/test_service.cpp
@@ -49,7 +49,7 @@ public:
     *this->node_ptr = rcl_get_zero_initialized_node();
     const char * name = "node_name";
     rcl_node_options_t node_options = rcl_node_get_default_options();
-    ret = rcl_node_init(this->node_ptr, name, &node_options);
+    ret = rcl_node_init(this->node_ptr, name, "", &node_options);
     ASSERT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
     set_on_unexpected_malloc_callback([]() {ASSERT_FALSE(true) << "UNEXPECTED MALLOC";});
     set_on_unexpected_realloc_callback([]() {ASSERT_FALSE(true) << "UNEXPECTED REALLOC";});
diff --git a/rcl/test/rcl/test_subscription.cpp b/rcl/test/rcl/test_subscription.cpp
index 9d783a8..f3693c6 100644
--- a/rcl/test/rcl/test_subscription.cpp
+++ b/rcl/test/rcl/test_subscription.cpp
@@ -50,7 +50,7 @@ public:
     *this->node_ptr = rcl_get_zero_initialized_node();
     const char * name = "node_name";
     rcl_node_options_t node_options = rcl_node_get_default_options();
-    ret = rcl_node_init(this->node_ptr, name, &node_options);
+    ret = rcl_node_init(this->node_ptr, name, "", &node_options);
     ASSERT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
     set_on_unexpected_malloc_callback([]() {ASSERT_FALSE(true) << "UNEXPECTED MALLOC";});
     set_on_unexpected_realloc_callback([]() {ASSERT_FALSE(true) << "UNEXPECTED REALLOC";});
diff --git a/rcl_lifecycle/test/test_default_state_machine.cpp b/rcl_lifecycle/test/test_default_state_machine.cpp
index 1d2774c..88c724a 100644
--- a/rcl_lifecycle/test/test_default_state_machine.cpp
+++ b/rcl_lifecycle/test/test_default_state_machine.cpp
@@ -42,7 +42,7 @@ protected:
     *this->node_ptr = rcl_get_zero_initialized_node();
     const char * name = "node_name";
     rcl_node_options_t node_options = rcl_node_get_default_options();
-    ret = rcl_node_init(this->node_ptr, name, &node_options);
+    ret = rcl_node_init(this->node_ptr, name, "", &node_options);
     ASSERT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
   }
 
diff --git a/rcl_lifecycle/test/test_multiple_instances.cpp b/rcl_lifecycle/test/test_multiple_instances.cpp
index 4a34020..1b9141b 100644
--- a/rcl_lifecycle/test/test_multiple_instances.cpp
+++ b/rcl_lifecycle/test/test_multiple_instances.cpp
@@ -42,7 +42,7 @@ protected:
     *this->node_ptr = rcl_get_zero_initialized_node();
     const char * name = "node_name";
     rcl_node_options_t node_options = rcl_node_get_default_options();
-    ret = rcl_node_init(this->node_ptr, name, &node_options);
+    ret = rcl_node_init(this->node_ptr, name, "", &node_options);
     ASSERT_EQ(RCL_RET_OK, ret) << rcl_get_error_string_safe();
   }