diff --git a/python/src/_py_mscclpp.cpp b/python/src/_py_mscclpp.cpp
index 3171122d..a0df9f28 100644
--- a/python/src/_py_mscclpp.cpp
+++ b/python/src/_py_mscclpp.cpp
@@ -128,16 +128,24 @@ struct _Comm {
 };
 
 struct _P2PHandle {
-  struct mscclppRegisteredMemoryP2P _rmP2P;
-  struct mscclppIbMr _ibmr;
+  struct mscclppRegisteredMemoryP2P _rm;
+  struct mscclppIbMr _local_ibmr;
 
-  _P2PHandle() : _rmP2P({0}), _ibmr({0}) {}
+  _P2PHandle() : _rm({0}), _local_ibmr({0}) {}
 
-  _P2PHandle(const mscclppRegisteredMemoryP2P& p2p) : _ibmr({0}) {
-    _rmP2P = p2p;
-    if (_rmP2P.IbMr != nullptr) {
-      _ibmr = *_rmP2P.IbMr;
-      _rmP2P.IbMr = &_ibmr;
+  _P2PHandle(const mscclppRegisteredMemoryP2P& p2p) : _local_ibmr({0}) {
+    _rm = p2p;
+    if (_rm.IbMr != nullptr) {
+      _local_ibmr = *_rm.IbMr;
+      _rm.IbMr = &_local_ibmr;
+    }
+  }
+
+  mscclppTransport_t transport() const {
+    if (_rm.IbMr != nullptr) {
+      return mscclppTransport_t::mscclppTransportIB;
+    } else {
+      return mscclppTransport_t::mscclppTransportP2P;
     }
   }
 };
@@ -209,7 +217,60 @@ NB_MODULE(_py_mscclpp, m) {
       });
 
   nb::class_<_P2PHandle>(m, "_P2PHandle")
-      .def_ro_static("__doc__", &DOC__P2PHandle);
+      .def_ro_static("__doc__", &DOC__P2PHandle)
+      .def(
+          "transport",
+          &_P2PHandle::transport,
+          "Get the transport type of the handle")
+      .def(
+          "data_ptr",
+          [](const _P2PHandle& self) -> uint64_t {
+            if (self.transport() == mscclppTransport_t::mscclppTransportP2P) {
+              return reinterpret_cast<uint64_t>(self._rm.remoteBuff);
+            }
+            throw std::invalid_argument(
+                "IB transport does not have a local data ptr");
+          },
+          "Get the local data pointer, only for P2P handles");
+
+  nb::class_<mscclppRegisteredMemory>(m, "_RegisteredMemory")
+      .def(
+          "handles",
+          [](const mscclppRegisteredMemory& self) -> std::vector<_P2PHandle> {
+            std::vector<_P2PHandle> handles;
+            for (const auto& p2p : self.p2p) {
+              handles.push_back(_P2PHandle(p2p));
+            }
+            return handles;
+          },
+          "Get the P2P handle for this memory")
+      .def(
+          "write_all",
+          [](const mscclppRegisteredMemory& self,
+             const _Comm& comm,
+             uint64_t src_data,
+             size_t size,
+             uint32_t src_offset = 0,
+             uint32_t dst_offset = 0,
+             int64_t stream = 0) -> void {
+            checkResult(
+                mscclppRegisteredBufferWrite(
+                    comm._handle,
+                    const_cast<mscclppRegisteredMemory*>(&self),
+                    reinterpret_cast<void*>(src_data),
+                    size,
+                    src_offset,
+                    dst_offset,
+                    stream),
+                "Failed to write to registered memory");
+          },
+          "comm"_a,
+          "src_data"_a,
+          "size"_a,
+          "src_offset"_a = 0,
+          "dst_offset"_a = 0,
+          "stream"_a = 0,
+          "Write to all bound targets in the buffer");
 
   nb::class_<_Comm>(m, "_Comm")
       .def_ro_static("__doc__", &DOC__Comm)
@@ -248,58 +309,54 @@ NB_MODULE(_py_mscclpp, m) {
           "id"_a,
           "rank"_a,
           "world_size"_a,
-          "Initialize comms given u UniqueID, rank, and world_size")
+          "Initialize comms given UniqueID, rank, and world_size")
       .def(
           "opened",
-          [](_Comm& comm) -> bool { return comm._is_open; },
+          [](_Comm& self) -> bool { return self._is_open; },
           "Is this comm object opened?")
       .def(
           "closed",
-          [](_Comm& comm) -> bool { return !comm._is_open; },
+          [](_Comm& self) -> bool { return !self._is_open; },
           "Is this comm object closed?")
       .def_ro("rank", &_Comm::_rank)
       .def_ro("world_size", &_Comm::_world_size)
       .def(
           "register_buffer",
-          [](_Comm& comm,
-             uint64_t local_buff,
-             uint64_t buff_size) -> std::vector<_P2PHandle> {
-            comm.check_open();
+          [](_Comm& self,
+             uint64_t data_ptr,
+             uint64_t size) -> mscclppRegisteredMemory {
+            self.check_open();
             mscclppRegisteredMemory regMem;
             checkResult(
                 mscclppRegisterBuffer(
-                    comm._handle,
-                    reinterpret_cast<void*>(local_buff),
-                    buff_size,
+                    self._handle,
+                    reinterpret_cast<void*>(data_ptr),
+                    size,
                     &regMem),
                 "Registering buffer failed");
-
-            std::vector<_P2PHandle> handles;
-            for (const auto& p2p : regMem.p2p) {
-              handles.push_back(_P2PHandle(p2p));
-            }
-            return handles;
+            return regMem;
+            ;
           },
-          "local_buf"_a,
-          "buff_size"_a,
+          "data_ptr"_a,
+          "size"_a,
           nb::call_guard<nb::gil_scoped_release>(),
           "Register a buffer for P2P transfers.")
       .def(
           "connect",
-          [](_Comm& comm,
+          [](_Comm& self,
              int remote_rank,
              int tag,
-             uint64_t local_buff,
-             uint64_t buff_size,
+             uint64_t data_ptr,
+             uint64_t size,
              mscclppTransport_t transport_type) -> void {
-            comm.check_open();
+            self.check_open();
             RETRY(
                 mscclppConnect(
-                    comm._handle,
+                    self._handle,
                     remote_rank,
                     tag,
-                    reinterpret_cast<void*>(local_buff),
-                    buff_size,
+                    reinterpret_cast<void*>(data_ptr),
+                    size,
                     transport_type,
                     NULL  // ibDev
                     ),
@@ -307,44 +364,44 @@ NB_MODULE(_py_mscclpp, m) {
           },
           "remote_rank"_a,
           "tag"_a,
-          "local_buf"_a,
-          "buff_size"_a,
+          "data_ptr"_a,
+          "size"_a,
           "transport_type"_a,
           nb::call_guard<nb::gil_scoped_release>(),
           "Attach a local buffer to a remote connection.")
       .def(
           "connection_setup",
-          [](_Comm& comm) -> void {
-            comm.check_open();
+          [](_Comm& self) -> void {
+            self.check_open();
             RETRY(
-                mscclppConnectionSetup(comm._handle),
+                mscclppConnectionSetup(self._handle),
                 "Failed to setup MSCCLPP connection");
           },
           nb::call_guard<nb::gil_scoped_release>(),
           "Run connection setup for MSCCLPP.")
       .def(
           "launch_proxies",
-          [](_Comm& comm) -> void {
-            comm.check_open();
-            if (comm._proxies_running) {
+          [](_Comm& self) -> void {
+            self.check_open();
+            if (self._proxies_running) {
               throw std::invalid_argument("Proxy Threads Already Running");
             }
             checkResult(
-                mscclppProxyLaunch(comm._handle),
+                mscclppProxyLaunch(self._handle),
                 "Failed to launch MSCCLPP proxy");
-            comm._proxies_running = true;
+            self._proxies_running = true;
           },
           nb::call_guard<nb::gil_scoped_release>(),
           "Start the MSCCLPP proxy.")
       .def(
           "stop_proxies",
-          [](_Comm& comm) -> void {
-            comm.check_open();
-            if (comm._proxies_running) {
+          [](_Comm& self) -> void {
+            self.check_open();
+            if (self._proxies_running) {
               checkResult(
-                  mscclppProxyStop(comm._handle),
+                  mscclppProxyStop(self._handle),
                   "Failed to stop MSCCLPP proxy");
-              comm._proxies_running = false;
+              self._proxies_running = false;
             }
           },
           nb::call_guard<nb::gil_scoped_release>(),
@@ -353,10 +410,10 @@ NB_MODULE(_py_mscclpp, m) {
       .def("__del__", &_Comm::close, nb::call_guard<nb::gil_scoped_release>())
       .def(
           "bootstrap_all_gather_int",
-          [](_Comm& comm, int val) -> std::vector<int> {
-            std::vector<int> buf(comm._world_size);
-            buf[comm._rank] = val;
-            mscclppBootstrapAllGather(comm._handle, buf.data(), sizeof(int));
+          [](_Comm& self, int val) -> std::vector<int> {
+            std::vector<int> buf(self._world_size);
+            buf[self._rank] = val;
+            mscclppBootstrapAllGather(self._handle, buf.data(), sizeof(int));
             return buf;
           },
           nb::call_guard<nb::gil_scoped_release>(),
@@ -364,13 +421,13 @@ NB_MODULE(_py_mscclpp, m) {
           "all-gather ints over the bootstrap connection.")
       .def(
           "all_gather_bytes",
-          [](_Comm& comm, nb::bytes& item) -> std::vector<nb::bytes> {
+          [](_Comm& self, nb::bytes& item) -> std::vector<nb::bytes> {
             // First, all-gather the sizes of all bytes.
-            std::vector<size_t> sizes(comm._world_size);
-            sizes[comm._rank] = item.size();
+            std::vector<size_t> sizes(self._world_size);
+            sizes[self._rank] = item.size();
             checkResult(
                 mscclppBootstrapAllGather(
-                    comm._handle, sizes.data(), sizeof(size_t)),
+                    self._handle, sizes.data(), sizeof(size_t)),
                 "bootstrapAllGather failed.");
 
             // Next, find the largest message to send.
@@ -378,21 +435,21 @@ NB_MODULE(_py_mscclpp, m) {
 
             // Allocate an all-gather buffer large enough for max * world_size.
             std::shared_ptr<char[]> data_buf(
-                new char[max_size * comm._world_size]);
+                new char[max_size * self._world_size]);
 
             // Copy the local item into the buffer.
             std::memcpy(
-                &data_buf[comm._rank * max_size], item.c_str(), item.size());
+                &data_buf[self._rank * max_size], item.c_str(), item.size());
 
             // all-gather the data buffer.
             checkResult(
                 mscclppBootstrapAllGather(
-                    comm._handle, data_buf.get(), max_size),
+                    self._handle, data_buf.get(), max_size),
                 "bootstrapAllGather failed.");
 
             // Build a response vector.
             std::vector<nb::bytes> ret;
-            for (int i = 0; i < comm._world_size; ++i) {
+            for (int i = 0; i < self._world_size; ++i) {
               // Copy out the relevant range of each item.
               ret.push_back(nb::bytes(&data_buf[i * max_size], sizes[i]));
             }
diff --git a/python/src/mscclpp/__init__.py b/python/src/mscclpp/__init__.py
index 51c564d8..defec50f 100644
--- a/python/src/mscclpp/__init__.py
+++ b/python/src/mscclpp/__init__.py
@@ -10,14 +10,8 @@ logger = logging.getLogger(__file__)
 
 from . import _py_mscclpp
 
-__all__ = (
-    "Comm",
-    "MscclppUniqueId",
-    "MSCCLPP_UNIQUE_ID_BYTES",
-    "TransportType",
-)
-
 _Comm = _py_mscclpp._Comm
+_RegisteredMemory = _py_mscclpp._RegisteredMemory
 _P2PHandle = _py_mscclpp._P2PHandle
 TransportType = _py_mscclpp.TransportType
 
@@ -67,7 +61,7 @@ _setup_logging()
 class Comm:
     """Comm object; represents a mscclpp connection."""
 
-    _comm: _Comm
+    _c_comm: _Comm
 
     @staticmethod
     def init_rank_from_address(
@@ -97,16 +91,16 @@ class Comm:
 
     def __init__(self, *, _comm: _Comm):
         """Construct a Comm object wrapping an internal _Comm handle."""
-        self._comm = _comm
+        self._c_comm = _comm
 
     def __del__(self) -> None:
         self.close()
 
     def close(self) -> None:
         """Close the connection."""
-        if self._comm:
-            self._comm.close()
-            self._comm = None
+        if self._c_comm:
+            self._c_comm.close()
+            self._c_comm = None
 
     @property
     def rank(self) -> int:
@@ -114,7 +108,7 @@ class Comm:
 
         Assumes the Comm is open.
         """
-        return self._comm.rank
+        return self._c_comm.rank
 
     @property
     def world_size(self) -> int:
@@ -122,11 +116,11 @@ class Comm:
 
         Assumes the Comm is open.
         """
-        return self._comm.world_size
+        return self._c_comm.world_size
 
     def bootstrap_all_gather_int(self, val: int) -> list[int]:
         """AllGather an int value through the bootstrap interface."""
-        return self._comm.bootstrap_all_gather_int(val)
+        return self._c_comm.bootstrap_all_gather_int(val)
 
     def all_gather_bytes(self, item: bytes) -> list[bytes]:
         """AllGather bytes (of different sizes) through the bootstrap interface.
@@ -134,7 +128,7 @@ class Comm:
         :param item: the bytes object for this rank.
         :return: a list of bytes objects; the ret[rank] object will be a new copy.
         """
-        return self._comm.all_gather_bytes(item)
+        return self._c_comm.all_gather_bytes(item)
 
     def all_gather_json(self, item: Any) -> list[Any]:
         """AllGather JSON objects through the bootstrap interface.
@@ -163,7 +157,7 @@ class Comm:
         data_size: int,
         transport: int,
     ) -> None:
-        self._comm.connect(
+        self._c_comm.connect(
             remote_rank,
             tag,
             data_ptr,
@@ -172,32 +166,79 @@ class Comm:
         )
 
     def connection_setup(self) -> None:
-        self._comm.connection_setup()
+        self._c_comm.connection_setup()
 
     def launch_proxies(self) -> None:
-        self._comm.launch_proxies()
+        self._c_comm.launch_proxies()
 
     def stop_proxies(self) -> None:
-        self._comm.stop_proxies()
+        self._c_comm.stop_proxies()
 
     def register_buffer(
         self,
-        data_ptr,
-        data_size: int,
-    ) -> list[_P2PHandle]:
+        data_ptr: int,
+        size: int,
+    ) -> "RegisteredMemory":
+        return RegisteredMemory(
+            comm=self._c_comm,
+            rm=self._c_comm.register_buffer(
+                data_ptr=data_ptr,
+                size=size,
+            ),
+        )
+
+
+class RegisteredMemory:
+    _comm: Comm
+    _c_rm: _RegisteredMemory
+
+    def __init__(
+        self,
+        *,
+        comm: Comm,
+        rm: _RegisteredMemory,
+    ):
+        self._comm = comm
+        self._c_rm = rm
+
+    def handles(self) -> list["P2PHandle"]:
         return [
-            P2PHandle(self, h)
-            for h in self._comm.register_buffer(
-                data_ptr,
-                data_size,
+            P2PHandle(
+                comm=self._comm,
+                handle=h,
             )
+            for h in self._c_rm.handles()
         ]
 
+    def _write(
+        self,
+        src_ptr: int,
+        size: int,
+        *,
+        src_offset: int = 0,
+        dst_offset: int = 0,
+        stream: int = 0,
+    ) -> None:
+        self._c_rm.write_all(
+            comm=self._comm._c_comm,
+            src_data=src_ptr,
+            size=size,
+            src_offset=src_offset,
+            dst_offset=dst_offset,
+            stream=stream,
+        )
+
 
 class P2PHandle:
     _comm: Comm
-    _handle: _P2PHandle
+    _c_handle: _P2PHandle
 
-    def __init__(self, comm: Comm, handle: _P2PHandle):
+    def __init__(self, *, comm: Comm, handle: _P2PHandle):
         self._comm = comm
-        self._handle = handle
+        self._c_handle = handle
+
+    def transport(self) -> TransportType:
+        return self._c_handle.transport()
+
+    def data_ptr(self) -> int:
+        return self._c_handle.data_ptr()
diff --git a/python/src/mscclpp/tests/bootstrap_test.py b/python/src/mscclpp/tests/bootstrap_test.py
index 0d5d8aa1..9915e7be 100644
--- a/python/src/mscclpp/tests/bootstrap_test.py
+++ b/python/src/mscclpp/tests/bootstrap_test.py
@@ -95,11 +95,22 @@ def _test_rm(options: argparse.Namespace, comm: mscclpp.Comm):
         mscclpp.TransportType.P2P,
     )
 
-    handles = comm.register_buffer(buf.data_ptr(), buf.element_size() * buf.numel())
+    rm = comm.register_buffer(buf.data_ptr(), buf.element_size() * buf.numel())
+    handles = rm.handles()
     hamcrest.assert_that(
         handles,
         hamcrest.has_length(options.world_size - 1),
     )
+    for handle in handles:
+        hamcrest.assert_that(
+            handle.transport(),
+            hamcrest.equal_to(mscclpp.TransportType.P2P),
+        )
+        # assuming P2P ...
+        hamcrest.assert_that(
+            handle.data_ptr(),
+            hamcrest.greater_than(0),
+        )
 
     torch.cuda.synchronize()