diff --git a/.utils/qa/scspell.dict b/.utils/qa/scspell.dict
index fa7d79e..bd960bd 100644
--- a/.utils/qa/scspell.dict
+++ b/.utils/qa/scspell.dict
@@ -40,7 +40,9 @@ sherikov
 sstream
 stringstream
 strstream
+todo
 typeid
+typeindex
 yaml
 zstd
 
diff --git a/frontend/include/intrometry/backend/utils.h b/frontend/include/intrometry/backend/utils.h
index 46019f4..982fbbe 100644
--- a/frontend/include/intrometry/backend/utils.h
+++ b/frontend/include/intrometry/backend/utils.h
@@ -14,6 +14,7 @@
 #include <unordered_map>
 #include <functional>
 #include <typeinfo>
+#include <typeindex>
 
 #include <ariles2/ariles.h>
 
@@ -60,67 +61,102 @@ namespace intrometry::backend
     class INTROMETRY_HIDDEN SourceContainer
     {
     protected:
-        // passthrough hasher
+        using Key = std::pair<std::type_index, std::string>;
+
         struct Hasher
         {
-            std::size_t operator()(const std::size_t key) const
+            std::size_t operator()(const Key &key) const
             {
-                return key;
+                std::size_t result = std::hash<std::type_index>{}(key.first);
+                if (not key.second.empty())
+                {
+                    result ^= std::hash<std::string>{}(key.second) + 0x9e3779b9 + (result << 6) + (result >> 2);
+                }
+                return (result);
             }
         };
 
-        using SourceMap = std::unordered_map<std::size_t, t_Value, Hasher>;
+        using SourceMap = std::unordered_map<Key, t_Value, Hasher>;
+        using CollisionMap = std::unordered_map<std::string, std::size_t>;
 
     protected:
         SourceMap sources_;
+        CollisionMap collision_counters_;
 
         std::mutex update_mutex_;
-        std::mutex drain_mutex_;
+        std::mutex flush_mutex_;
 
     protected:
-        static std::size_t hash(const ariles2::DefaultBase &source)
+        /// @todo requires string copy
+        static Key getKey(const std::string &id, const ariles2::DefaultBase &source)
         {
-            // redundant
-            // const std::size_t ariles_hash = std::hash<std::string>{}(source.arilesDefaultID());
-            return (typeid(source).hash_code());
+            // source.arilesDefaultID()
+            // this is redundant and less reliable than type_index
+            // since it is provided by the user
+
+            // id
+            // this is also provided by the user and is also unreliable,
+            // but in general provides extra information than type_index
+            // and should be added to hash
+            return (Key(std::type_index(typeid(source)), id));
+        }
+
+        std::string getUniqueId(const std::string &id)
+        {
+            const typename CollisionMap::iterator collision_counter_it = collision_counters_.find(id);
+            if (collision_counters_.end() == collision_counter_it)
+            {
+                collision_counters_[id] = 0;
+                return (id);
+            }
+
+            ++collision_counter_it->second;
+            return (str_concat(id, "_intrometry", std::to_string(collision_counter_it->second)));
         }
 
     public:
         void tryVisit(const std::function<void(t_Value &)> visitor)
         {
-            if (drain_mutex_.try_lock())
+            if (flush_mutex_.try_lock())
             {
-                for (std::pair<const std::size_t, t_Value> &source : sources_)
+                for (std::pair<const Key, t_Value> &source : sources_)
                 {
                     visitor(source.second);
                 }
 
-                drain_mutex_.unlock();
+                flush_mutex_.unlock();
             }
         }
 
         template <class... t_Args>
-        void tryEmplace(const ariles2::DefaultBase &source, t_Args &&...args)
+        void tryEmplace(const std::string &id, const ariles2::DefaultBase &source, t_Args &&...args)
         {
             const std::lock_guard<std::mutex> update_lock(update_mutex_);
-            const std::lock_guard<std::mutex> drain_lock(drain_mutex_);
+            const std::lock_guard<std::mutex> flush_lock(flush_mutex_);
 
-            sources_.try_emplace(hash(source), source, std::forward<t_Args>(args)...);
+            sources_.try_emplace(
+                    getKey(id, source),
+                    source,
+                    getUniqueId(id.empty() ? source.arilesDefaultID() : id),
+                    std::forward<t_Args>(args)...);
         }
 
-        void erase(const ariles2::DefaultBase &source)
+        void erase(const std::string &id, const ariles2::DefaultBase &source)
         {
             const std::lock_guard<std::mutex> update_lock(update_mutex_);
-            const std::lock_guard<std::mutex> drain_lock(drain_mutex_);
+            const std::lock_guard<std::mutex> flush_lock(flush_mutex_);
 
-            sources_.erase(hash(source));
+            sources_.erase(getKey(id, source));
         }
 
-        bool tryVisit(const ariles2::DefaultBase &source, const std::function<void(t_Value &)> visitor)
+        bool tryVisit(
+                const std::string &id,
+                const ariles2::DefaultBase &source,
+                const std::function<void(t_Value &)> visitor)
         {
             if (update_mutex_.try_lock())
             {
-                const typename SourceMap::iterator source_it = sources_.find(hash(source));
+                const typename SourceMap::iterator source_it = sources_.find(getKey(id, source));
 
                 if (sources_.end() == source_it)
                 {
diff --git a/frontend/include/intrometry/sink.h b/frontend/include/intrometry/sink.h
index 5187d09..ff09a59 100644
--- a/frontend/include/intrometry/sink.h
+++ b/frontend/include/intrometry/sink.h
@@ -41,7 +41,12 @@ namespace intrometry
          *
          * @note Does nothing if initialization failed.
          */
+        void assign(const ariles2::DefaultBase &source, const Source::Parameters &parameters = Source::Parameters())
+        {
+            assign(std::string(), source, parameters);
+        }
         virtual void assign(
+                const std::string &id,  // use to resolve ambiguity between sources of the same type
                 const ariles2::DefaultBase &source,
                 const Source::Parameters &parameters = Source::Parameters()) = 0;
 
@@ -52,7 +57,11 @@ namespace intrometry
          * @note Does nothing if initialization failed.
          * @note Does nothing if the source has not been assigned.
          */
-        virtual void retract(const ariles2::DefaultBase &source) = 0;
+        void retract(const ariles2::DefaultBase &source)
+        {
+            retract(std::string(), source);
+        }
+        virtual void retract(const std::string &id, const ariles2::DefaultBase &source) = 0;
 
         /**
          * Write data. Data is copied to internal buffers, and scheduled for
@@ -61,7 +70,11 @@ namespace intrometry
          * @note Does nothing if source is unassigned.
          * @note Does nothing if initialization failed.
          */
-        virtual void write(const ariles2::DefaultBase &source, const uint64_t timestamp = 0) = 0;
+        void write(const ariles2::DefaultBase &source, const uint64_t timestamp = 0)
+        {
+            write(std::string(), source, timestamp);
+        }
+        virtual void write(const std::string &id, const ariles2::DefaultBase &source, const uint64_t timestamp = 0) = 0;
 
 
         /// Batch assignment
diff --git a/pjmsg_mcap/include/intrometry/pjmsg_mcap/sink.h b/pjmsg_mcap/include/intrometry/pjmsg_mcap/sink.h
index 6548ae4..04ed867 100644
--- a/pjmsg_mcap/include/intrometry/pjmsg_mcap/sink.h
+++ b/pjmsg_mcap/include/intrometry/pjmsg_mcap/sink.h
@@ -37,7 +37,7 @@ namespace intrometry::pjmsg_mcap
 
         public:
             Parameters(const std::string &id = "");  // NOLINT
-            Parameters(const char *id = "");  // NOLINT
+            Parameters(const char *id = "");         // NOLINT
 
             Parameters &rate(const std::size_t value);
             Parameters &id(const std::string &value);
@@ -55,11 +55,17 @@ namespace intrometry::pjmsg_mcap
     {
     public:
         using SinkPIMPLBase::SinkPIMPLBase;
+        using SinkPIMPLBase::assign;
+        using SinkPIMPLBase::write;
+        using SinkPIMPLBase::retract;
         ~Sink();
 
         bool initialize();
-        void assign(const ariles2::DefaultBase &source, const Source::Parameters &parameters = Source::Parameters());
-        void retract(const ariles2::DefaultBase &source);
-        void write(const ariles2::DefaultBase &source, const uint64_t timestamp = 0);
+        void assign(
+                const std::string &id,
+                const ariles2::DefaultBase &source,
+                const Source::Parameters &parameters = Source::Parameters());
+        void retract(const std::string &id, const ariles2::DefaultBase &source);
+        void write(const std::string &id, const ariles2::DefaultBase &source, const uint64_t timestamp = 0);
     };
 }  // namespace intrometry::pjmsg_mcap
diff --git a/pjmsg_mcap/src/intrometry.cpp b/pjmsg_mcap/src/intrometry.cpp
index dd03375..9540bb2 100644
--- a/pjmsg_mcap/src/intrometry.cpp
+++ b/pjmsg_mcap/src/intrometry.cpp
@@ -206,6 +206,7 @@ namespace
     {
     public:
         std::mutex mutex_;
+        const std::string id_;
         ariles2::namevalue2::Writer::Parameters writer_parameters_;
         std::shared_ptr<NameValueContainer> data_;
         ariles2::namevalue2::Writer writer_;
@@ -213,8 +214,12 @@ namespace
         bool serialized_;
 
     public:
-        WriterWrapper(const ariles2::DefaultBase &source, const bool persistent_structure, uint32_t &names_version)
-          : data_(std::make_shared<NameValueContainer>()), writer_(data_)
+        WriterWrapper(
+                const ariles2::DefaultBase &source,
+                std::string id,
+                const bool persistent_structure,
+                uint32_t &names_version)
+          : id_(std::move(id)), data_(std::make_shared<NameValueContainer>()), writer_(data_)
         {
             writer_parameters_ = writer_.getDefaultParameters();
             if (persistent_structure)
@@ -223,7 +228,7 @@ namespace
             }
 
             // write to allocate memory
-            ariles2::apply(writer_, source);
+            ariles2::apply(writer_, source, id_);
             data_->finalize(writer_parameters_.persistent_structure_, 0, names_version);
 
             serialized_ = true;  // do not serialize on assignment
@@ -252,7 +257,7 @@ namespace
         {
             if (mutex_.try_lock())
             {
-                ariles2::apply(writer_, source);
+                ariles2::apply(writer_, source, id_);
                 data_->finalize(writer_parameters_.persistent_structure_, timestamp, names_version);
                 serialized_ = false;
 
@@ -302,12 +307,13 @@ namespace intrometry::pjmsg_mcap::sink
     class Implementation
     {
     protected:
-        tut::thread::Supervisor<> thread_supervisor_;
+        McapCDRWriter mcap_writer_;
+
+    public:
         uint32_t names_version_;
 
         intrometry::backend::SourceContainer<WriterWrapper> sources_;
-
-        McapCDRWriter mcap_writer_;
+        tut::thread::Supervisor<> thread_supervisor_;
 
     public:
         Implementation(const std::filesystem::path &directory, const std::string &sink_id, const std::size_t rate)
@@ -369,31 +375,6 @@ namespace intrometry::pjmsg_mcap::sink
             }
             thread_supervisor_.interrupt();
         }
-
-
-        void assign(const ariles2::DefaultBase &source, const Source::Parameters &parameters)
-        {
-            sources_.tryEmplace(source, parameters.persistent_structure_, names_version_);
-        }
-
-        void retract(const ariles2::DefaultBase &source)
-        {
-            sources_.erase(source);
-        }
-
-        void write(const ariles2::DefaultBase &source, const uint64_t timestamp)
-        {
-            if (not sources_.tryVisit(
-                        source,
-                        [this, &source, timestamp](WriterWrapper &writer) {
-                            writer.write(
-                                    source, (0 == timestamp) ? intrometry::backend::now() : timestamp, names_version_);
-                        }))
-            {
-                thread_supervisor_.log(
-                        "Measurement source handler is not assigned, skipping id: ", source.arilesDefaultID());
-            }
-        }
     };
 }  // namespace intrometry::pjmsg_mcap::sink
 
@@ -414,29 +395,41 @@ namespace intrometry::pjmsg_mcap
     }
 
 
-    void Sink::assign(const ariles2::DefaultBase &source, const Source::Parameters &parameters)
+    void Sink::assign(const std::string &id, const ariles2::DefaultBase &source, const Source::Parameters &parameters)
     {
         if (pimpl_)
         {
-            pimpl_->assign(source, parameters);
+            pimpl_->sources_.tryEmplace(id, source, parameters.persistent_structure_, pimpl_->names_version_);
         }
     }
 
 
-    void Sink::retract(const ariles2::DefaultBase &source)
+    void Sink::retract(const std::string &id, const ariles2::DefaultBase &source)
     {
         if (pimpl_)
         {
-            pimpl_->retract(source);
+            pimpl_->sources_.erase(id, source);
         }
     }
 
 
-    void Sink::write(const ariles2::DefaultBase &source, const uint64_t timestamp)
+    void Sink::write(const std::string &id, const ariles2::DefaultBase &source, const uint64_t timestamp)
     {
         if (pimpl_)
         {
-            pimpl_->write(source, timestamp);
+            if (not pimpl_->sources_.tryVisit(
+                        id,
+                        source,
+                        [this, &source, &timestamp](WriterWrapper &writer) {
+                            writer.write(
+                                    source,
+                                    (0 == timestamp) ? intrometry::backend::now() : timestamp,
+                                    pimpl_->names_version_);
+                        }))
+            {
+                pimpl_->thread_supervisor_.log(
+                        "Measurement source handler is not assigned, skipping id: ", source.arilesDefaultID());
+            }
         }
     }
 }  // namespace intrometry::pjmsg_mcap
diff --git a/pjmsg_topic/include/intrometry/pjmsg_topic/sink.h b/pjmsg_topic/include/intrometry/pjmsg_topic/sink.h
index f5f0e9c..a67cedd 100644
--- a/pjmsg_topic/include/intrometry/pjmsg_topic/sink.h
+++ b/pjmsg_topic/include/intrometry/pjmsg_topic/sink.h
@@ -30,7 +30,7 @@ namespace intrometry::pjmsg_topic
 
         public:
             Parameters(const std::string &id = "");  // NOLINT
-            Parameters(const char *id = "");  // NOLINT
+            Parameters(const char *id = "");         // NOLINT
 
             Parameters &rate(const std::size_t value);
             Parameters &id(const std::string &value);
@@ -47,11 +47,17 @@ namespace intrometry::pjmsg_topic
     {
     public:
         using SinkPIMPLBase::SinkPIMPLBase;
+        using SinkPIMPLBase::assign;
+        using SinkPIMPLBase::write;
+        using SinkPIMPLBase::retract;
         ~Sink();
 
         bool initialize();
-        void assign(const ariles2::DefaultBase &source, const Source::Parameters &parameters = Source::Parameters());
-        void retract(const ariles2::DefaultBase &source);
-        void write(const ariles2::DefaultBase &source, const uint64_t timestamp = 0);
+        void assign(
+                const std::string &id,
+                const ariles2::DefaultBase &source,
+                const Source::Parameters &parameters = Source::Parameters());
+        void retract(const std::string &id, const ariles2::DefaultBase &source);
+        void write(const std::string &id, const ariles2::DefaultBase &source, const uint64_t timestamp = 0);
     };
 }  // namespace intrometry::pjmsg_topic
diff --git a/pjmsg_topic/src/intrometry.cpp b/pjmsg_topic/src/intrometry.cpp
index 1e1aba2..81be45e 100644
--- a/pjmsg_topic/src/intrometry.cpp
+++ b/pjmsg_topic/src/intrometry.cpp
@@ -93,6 +93,7 @@ namespace
     {
     public:
         std::mutex mutex_;
+        const std::string id_;
         ariles2::namevalue2::Writer::Parameters writer_parameters_;
         std::shared_ptr<NameValueContainer> data_;
         ariles2::namevalue2::Writer writer_;
@@ -101,8 +102,12 @@ namespace
 
 
     public:
-        WriterWrapper(const ariles2::DefaultBase &source, const bool persistent_structure, uint32_t &names_version)
-          : data_(std::make_shared<NameValueContainer>()), writer_(data_)
+        WriterWrapper(
+                const ariles2::DefaultBase &source,
+                std::string id,
+                const bool persistent_structure,
+                uint32_t &names_version)
+          : id_(std::move(id)), data_(std::make_shared<NameValueContainer>()), writer_(data_)
         {
             writer_parameters_ = writer_.getDefaultParameters();
             if (persistent_structure)
@@ -111,7 +116,7 @@ namespace
             }
 
             // write to allocate memory
-            ariles2::apply(writer_, source);
+            ariles2::apply(writer_, source, id_);
             data_->finalize(writer_parameters_.persistent_structure_, rclcpp::Time(0), names_version);
 
             published_ = true;  // do not publish on assignment
@@ -141,7 +146,7 @@ namespace
         {
             if (mutex_.try_lock())
             {
-                ariles2::apply(writer_, source);
+                ariles2::apply(writer_, source, id_);
                 data_->finalize(writer_parameters_.persistent_structure_, timestamp, names_version);
                 published_ = false;
 
@@ -216,16 +221,19 @@ namespace intrometry::pjmsg_topic
     {
         class Implementation
         {
-        protected:
+        public:
             std::shared_ptr<rclcpp::Node> node_;
-            tut::thread::Supervisor<ROSLogger> thread_supervisor_;
-            uint32_t names_version_;
-
-            intrometry::backend::SourceContainer<WriterWrapper> sources_;
 
+        protected:
             NamesPublisherPtr names_publisher_;
             ValuesPublisherPtr values_publisher_;
 
+        public:
+            uint32_t names_version_;
+
+            intrometry::backend::SourceContainer<WriterWrapper> sources_;
+            tut::thread::Supervisor<ROSLogger> thread_supervisor_;
+
         public:
             Implementation(const std::string &sink_id, const std::size_t rate)
             {
@@ -293,33 +301,6 @@ namespace intrometry::pjmsg_topic
                 }
                 thread_supervisor_.interrupt();
             }
-
-
-            void assign(const ariles2::DefaultBase &source, const Source::Parameters &parameters)
-            {
-                sources_.tryEmplace(source, parameters.persistent_structure_, names_version_);
-            }
-
-            void retract(const ariles2::DefaultBase &source)
-            {
-                sources_.erase(source);
-            }
-
-            void write(const ariles2::DefaultBase &source, const rclcpp::Time &timestamp)
-            {
-                if (not sources_.tryVisit(
-                            source,
-                            [this, &source, &timestamp](WriterWrapper &writer) {
-                                writer.write(
-                                        source,
-                                        (0 == timestamp.nanoseconds()) ? node_->now() : timestamp,
-                                        names_version_);
-                            }))
-                {
-                    thread_supervisor_.log(
-                            "Measurement source handler is not assigned, skipping id: ", source.arilesDefaultID());
-                }
-            }
         };
     }  // namespace sink
 }  // namespace intrometry::pjmsg_topic
@@ -342,29 +323,43 @@ namespace intrometry::pjmsg_topic
     }
 
 
-    void Sink::assign(const ariles2::DefaultBase &source, const Source::Parameters &parameters)
+    void Sink::assign(const std::string &id, const ariles2::DefaultBase &source, const Source::Parameters &parameters)
     {
         if (pimpl_)
         {
-            pimpl_->assign(source, parameters);
+            pimpl_->sources_.tryEmplace(id, source, parameters.persistent_structure_, pimpl_->names_version_);
         }
     }
 
 
-    void Sink::retract(const ariles2::DefaultBase &source)
+    void Sink::retract(const std::string &id, const ariles2::DefaultBase &source)
     {
         if (pimpl_)
         {
-            pimpl_->retract(source);
+            pimpl_->sources_.erase(id, source);
         }
     }
 
 
-    void Sink::write(const ariles2::DefaultBase &source, const uint64_t timestamp)
+    void Sink::write(const std::string &id, const ariles2::DefaultBase &source, const uint64_t timestamp)
     {
         if (pimpl_)
         {
-            pimpl_->write(source, rclcpp::Time(static_cast<rcl_time_point_value_t>(timestamp)));
+            if (not pimpl_->sources_.tryVisit(
+                        id,
+                        source,
+                        [this, &source, &timestamp](WriterWrapper &writer)
+                        {
+                            writer.write(
+                                    source,
+                                    (0 == timestamp) ? pimpl_->node_->now() :
+                                                       rclcpp::Time(static_cast<rcl_time_point_value_t>(timestamp)),
+                                    pimpl_->names_version_);
+                        }))
+            {
+                pimpl_->thread_supervisor_.log(
+                        "Measurement source handler is not assigned, skipping id: ", source.arilesDefaultID());
+            }
         }
     }
 }  // namespace intrometry::pjmsg_topic