diff --git a/README.md b/README.md
index 316f463d..0431e039 100644
--- a/README.md
+++ b/README.md
@@ -17,13 +17,18 @@ the extras you use:
 
 ```bash
 python -m pip install -e '.[player]'    # interactive mesh viewer and GIF export
-python -m pip install -e '.[open3d]'    # RGB-D reconstruction
+python -m pip install -e '.[open3d]'    # RGB-D reconstruction (Open3D 0.19.x)
 python -m pip install -e '.[gaussians]' # read Gaussian PLY files
 ```
 
 Research methods have additional setup below. Their source, native programs
 and model weights are not bundled in the Python wheel.
 
+RGB-D reconstruction requires Open3D 0.19.x. The legacy TSDF integrator in
+Open3D 0.20 rescales already-metric float depth and can return empty meshes;
+the extra selects the supported version and reconstruction rejects an
+incompatible manually installed runtime before processing frames.
+
 ## Try a sequence
 
 No dataset is needed for this example:
@@ -151,10 +156,10 @@ with receive() as frames:
 Then send from another:
 
 ```python
-from open4d import stream
+from open4d import send
 from open4d.demo import mesh_sequence
 
-stream(mesh_sequence(frames=30))
+send(mesh_sequence(frames=30))
 ```
 
 This sends decoded mesh arrays over TCP, at their recorded frame timing. It is
diff --git a/docs/api.md b/docs/api.md
index c18e0fa5..e2e7ace2 100644
--- a/docs/api.md
+++ b/docs/api.md
@@ -63,7 +63,7 @@ index, and per-frame streams alongside the geometry — see the
 
 ## Streaming
 
-`open4d.stream` exports a sequence as a bundle and serves it to a browser:
+`open4d.stream` exports a file as a bundle and serves it to a browser:
 
 ```python
 import open4d
@@ -72,6 +72,12 @@ open4d.stream("capture.usdc")
 open4d.stream("capture.usdc", rungs=["draco", "draco@11"], out_dir="bundle/")
 ```
 
+For a loaded sequence, pass browser options such as `name="capture"` and
+`out_dir="bundle/"`. `open4d.send(sequence, host, port)` explicitly selects
+decoded-mesh TCP transport and pairs with `open4d.receive`. Existing
+`open4d.stream(sequence, host, port)` calls, and frame iterables without browser
+options, retain that TCP behavior without requiring `open4d-streamer`.
+
 `rungs` is the quality ladder. The first is the rendition a client plays by
 default and the rest are what it can switch to mid-playback, so a one-entry
 list is a fixed-quality stream and says so. A spec is a frame format —
diff --git a/docs/components.md b/docs/components.md
index 93947080..973316e1 100644
--- a/docs/components.md
+++ b/docs/components.md
@@ -21,7 +21,7 @@ hardware requirements to the shared Python baseline. See
 
 | Module | |
 |---|---|
-| [**RGB-D**](../open4d/reconstruction/rgbd/README.md) | Synchronized multi-camera RGB-D ingestion, calibrated point-cloud fusion, CUDA TSDF mesh reconstruction, and live browser playback. Includes both the original native reconstruction code and the Python two-camera streaming pipeline |
+| [**RGB-D**](../open4d/streaming/README.md) | Synchronized multi-camera RGB-D ingestion, calibrated point-cloud fusion, CUDA TSDF mesh reconstruction, and live browser playback. Includes both the original native reconstruction code and the Python two-camera streaming pipeline |
 | [**QUEEN**](../open4d/reconstruction/queen/README.md) | Quantized efficient encoding of dynamic Gaussians for streaming free-viewpoint video (NeurIPS 2024) |
 | [**3DGStream**](../open4d/reconstruction/3dgstream/README.md) | On-the-fly training of 3D Gaussians for streaming photo-realistic free-viewpoint video (CVPR 2024) |
 | [**Vega**](../open4d/reconstruction/vega/README.md) | An ORBIT adaptation of Vega (MobiCom 2025): mobile volumetric video streaming with 3D Gaussian splatting |
diff --git a/docs/requirements.md b/docs/requirements.md
index d40a92a9..a34b71ea 100644
--- a/docs/requirements.md
+++ b/docs/requirements.md
@@ -121,7 +121,7 @@ build. Those are optional and separate, with install commands in
 | `codecs/klt` | `kaolin` and an NVIDIA GPU; 24 GB is the same ceiling at resolution 128–256 |
 | `codecs/draco` | A CMake build of the vendored Draco submodule. Open3D, pymeshlab, and OpenCV are for evaluation only |
 | `codecs/vdmc`, `codecs/faster_vdmc` | The MPEG reference and optimized test models' own build requirements |
-| `reconstruction/rgbd` | Two hardware-synchronized RGB-D cameras, a Windows capture host, and an Ubuntu host with Python 3.10+, an NVIDIA GPU, and CUDA-enabled Open3D. Its legacy C++ pipeline additionally wants CUDA 12.x, Open3D 0.18, OpenCV, Eigen, jsoncpp, Draco, CMake, Ninja, and either the Azure Kinect SDK or the Orbbec K4A wrapper |
+| `streaming` | Two hardware-synchronized RGB-D cameras, a Windows capture host, and an Ubuntu host with Python 3.10+, an NVIDIA GPU, and CUDA-enabled Open3D. Its legacy C++ pipeline additionally wants CUDA 12.x, Open3D 0.18, OpenCV, Eigen, jsoncpp, Draco, CMake, Ninja, and either the Azure Kinect SDK or the Orbbec K4A wrapper |
 | `reconstruction/gs_tools`, `queen`, `3dgstream`, `vega` | The separate `open4d-gs` conda environment and five CUDA extensions built with `--no-build-isolation`, per [`gs_tools`](../open4d/reconstruction/gs_tools/README.md). Build on ext4; on an ntfs3 mount ninja deadlocks in `ntfs_file_write_iter` |
 | `reconstruction/rerf` | Python 3.8, because `ac_dc/ncvv_ac_dc.cpython-38-*.so` ships without sources and cannot be rebuilt for a newer interpreter. Plus torch with CUDA, mmcv, bitarray, Pillow, NumPy — a separate environment from every other module here |
 | `integrations/unity` | Unity, plus a C++ toolchain to rebuild the backend for anything other than the prebuilt macOS and Android/Quest 3 plugins |
@@ -136,5 +136,5 @@ with `Hardware MFT failed to start`. 5 synchronized pairs/s held over Wi-Fi and
 VPN; 15 did not.
 
 Calibration layout and the step-by-step session walkthrough are in
-[`open4d/reconstruction/rgbd/README.md`](../open4d/reconstruction/rgbd/README.md),
+[`open4d/streaming/README.md`](../open4d/streaming/README.md),
 which covers how to run the pipeline and leaves requirements to this page.
diff --git a/open4d/__init__.py b/open4d/__init__.py
index d427e05d..895cf6b7 100644
--- a/open4d/__init__.py
+++ b/open4d/__init__.py
@@ -23,8 +23,12 @@
     TriangleMesh,
     dtypes,
 )
-from ._api import load, save, unload
-from ._streamer import StreamerDependencyError, stream
+from ._api import load, save, unload, reconstruct, stream
+from ._streamer import StreamerDependencyError
+from .codec import available_codecs, decode_sequence as decode, encode_sequence as encode
+from .streaming import receive, send
+from .gaussians import GaussianSplats, GaussianRun, NeuralGaussianFrame, load_gaussians
+from .metrics import compare_meshes, compare_sequences
 from .visualization import visualize
 
 __all__ = [
@@ -64,7 +68,7 @@
     "receive",
     "stream",
     "save",
-    "stream",
+    "send",
     "unload",
     "visualize",
 ]
diff --git a/open4d/_api.py b/open4d/_api.py
index 21106ad4..27d40704 100644
--- a/open4d/_api.py
+++ b/open4d/_api.py
@@ -163,3 +163,22 @@ def reconstruct(source, output=None, *, method="rgbd", **options):
 
         return reconstruct_gaussians(source, output, method=method, **options)
     raise ValueError("method must be 'rgbd', 'queen' or '3dgstream'")
+
+
+def stream(source, *address, **options):
+    """Send mesh frames over TCP or export a sequence for browser playback.
+
+    A path, or browser options such as out_dir/name/rungs, selects the optional
+    browser streamer. A frame iterable without browser options retains the
+    original TCP behavior, including positional or keyword host/port arguments.
+    Use send() to select TCP explicitly.
+    """
+    browser_options = {"out_dir", "name", "title", "rungs", "fps", "open_browser", "block"}
+    if address or (not isinstance(source, (str, os.PathLike))
+                   and not browser_options.intersection(options)):
+        from .streaming import send
+
+        return send(source, *address, **options)
+    from ._streamer import stream as stream_to_browser
+
+    return stream_to_browser(source, **options)
diff --git a/open4d/core/tests/test_gaussians.py b/open4d/core/tests/test_gaussians.py
index b9d23cd6..ae1fd985 100644
--- a/open4d/core/tests/test_gaussians.py
+++ b/open4d/core/tests/test_gaussians.py
@@ -171,6 +171,7 @@ def test_reconstruction_refuses_existing_output_before_launch(tmp_path, cli_runt
 
 
 def test_native_render_commands_do_not_call_destructive_extractor(monkeypatch, tmp_path):
+    monkeypatch.setitem(sys.modules, "streamer", None)
     root = Path(__file__).resolve().parents[2] / "reconstruction" / "gs_tools"
     monkeypatch.syspath_prepend(str(root))
     try:
diff --git a/open4d/io/tests/test_public_stream_dispatch.py b/open4d/io/tests/test_public_stream_dispatch.py
new file mode 100644
index 00000000..180f84a5
--- /dev/null
+++ b/open4d/io/tests/test_public_stream_dispatch.py
@@ -0,0 +1,38 @@
+"""Public TCP compatibility and optional browser streaming coexist."""
+from concurrent.futures import ThreadPoolExecutor
+import sys
+
+import numpy as np
+import pytest
+
+import open4d
+from open4d.demo import mesh_sequence
+
+
+@pytest.mark.parametrize("entry", ["send", "stream"])
+@pytest.mark.parametrize("address_style", ["positional", "keyword"])
+def test_public_tcp_round_trip_without_browser_dependency(monkeypatch, entry, address_style):
+    monkeypatch.setitem(sys.modules, "streamer", None)
+    with mesh_sequence(side=3, frames=2) as source:
+        with open4d.receive(port=0, timeout=3) as receiver, ThreadPoolExecutor(1) as pool:
+            if address_style == "positional":
+                result = pool.submit(getattr(open4d, entry), source, *receiver.address,
+                                     realtime=False, timeout=3)
+            else:
+                result = pool.submit(getattr(open4d, entry), source,
+                                     host=receiver.address[0], port=receiver.address[1], timeout=3)
+            restored = list(receiver)
+            assert result.result(timeout=3) == 2
+        for expected, actual in zip(source, restored):
+            np.testing.assert_array_equal(actual.geometry.positions, expected.geometry.positions)
+            np.testing.assert_array_equal(actual.geometry.triangles, expected.geometry.triangles)
+            assert actual.timestamp == expected.timestamp
+
+
+@pytest.mark.parametrize("use_path", [True, False])
+def test_browser_requests_report_missing_optional_streamer(monkeypatch, tmp_path, use_path):
+    monkeypatch.setitem(sys.modules, "streamer", None)
+    with mesh_sequence(side=3, frames=1) as frames:
+        source = tmp_path/'capture.ply' if use_path else frames
+        with pytest.raises(open4d.StreamerDependencyError, match="pip install -e open4d/streamer"):
+            open4d.stream(source, name="capture", out_dir=tmp_path/'bundle', open_browser=False, block=False)
diff --git a/open4d/reconstruction/gs_tools/gs_tools/methods/__init__.py b/open4d/reconstruction/gs_tools/gs_tools/methods/__init__.py
index 48d4e60a..8ccc9544 100644
--- a/open4d/reconstruction/gs_tools/gs_tools/methods/__init__.py
+++ b/open4d/reconstruction/gs_tools/gs_tools/methods/__init__.py
@@ -11,6 +11,16 @@
 and the other cannot.
 """
 
-from . import base, gstream, queen, rerf, vega
+from importlib import import_module
 
 __all__ = ["base", "gstream", "queen", "rerf", "vega"]
+
+
+def __getattr__(name):
+    # Building a QUEEN/3DGStream command must not import the optional browser
+    # bundle exporters, which depend on the separately installed streamer.
+    if name not in __all__:
+        raise AttributeError(f"module {__name__!r} has no attribute {name!r}")
+    module = import_module(f".{name}", __name__)
+    globals()[name] = module
+    return module
diff --git a/open4d/streaming/_reconstruction.py b/open4d/streaming/_reconstruction.py
index 4bc56c3e..473af6dd 100644
--- a/open4d/streaming/_reconstruction.py
+++ b/open4d/streaming/_reconstruction.py
@@ -128,7 +128,7 @@ def reconstruct(depth, color=None, *, intrinsics, camera_poses=None, fps=30.0,
             or not np.allclose(np.linalg.det(rotation), 1, atol=1e-5)):
         raise ValueError("camera_poses must be rigid camera-to-world transforms")
     try:
-        importlib.import_module("open3d")
+        o3d = importlib.import_module("open3d")
     except ModuleNotFoundError as error:
         if error.name != "open3d":
             raise
@@ -136,5 +136,12 @@ def reconstruct(depth, color=None, *, intrinsics, camera_poses=None, fps=30.0,
             "RGB-D reconstruction needs Open3D. Install open4d[open3d].",
             name="open3d",
         ) from error
+    if o3d.__version__.split(".")[:2] != ["0", "19"]:
+        raise RuntimeError(
+            f"RGB-D reconstruction requires Open3D 0.19.x; found {o3d.__version__}. "
+            "Open3D 0.20's legacy TSDF integration rescales floating-point depth "
+            "and can silently return empty meshes. "
+            "Install a supported runtime with: python -m pip install 'open3d>=0.19,<0.20'"
+        )
     return Sequence(_RGBDProvider(depth, color, intrinsics, camera_poses, fps,
                                  depth_scale, depth_max, voxel_size, truncation))
diff --git a/open4d/streaming/tests/test_python.py b/open4d/streaming/tests/test_python.py
index a454e8b3..2002a57f 100644
--- a/open4d/streaming/tests/test_python.py
+++ b/open4d/streaming/tests/test_python.py
@@ -2,6 +2,8 @@
 import importlib
 import json
 import socket
+import sys
+from types import SimpleNamespace
 
 import numpy as np
 import pytest
@@ -121,6 +123,13 @@ def test_reconstruct_validates_before_loading_optional_dependencies(kwargs, matc
         reconstruct(np.ones((1, 32, 32)), **settings)
 
 
+@pytest.mark.parametrize("version", ["0.18.0", "0.20.0"])
+def test_reconstruct_rejects_unsupported_open3d_before_returning_a_sequence(monkeypatch, version):
+    monkeypatch.setitem(sys.modules, "open3d", SimpleNamespace(__version__=version))
+    with pytest.raises(RuntimeError, match=r"Open3D 0\.19\.x.*open3d>=0\.19,<0\.20"):
+        reconstruct(np.ones((1, 32, 32)), intrinsics=(20, 20, 16, 16))
+
+
 @pytest.mark.open3d
 def test_reconstruct_depth_planes_preserves_motion_units_and_camera_pose():
     pytest.importorskip("open3d")
diff --git a/pyproject.toml b/pyproject.toml
index a4746b1f..2360eddd 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -23,15 +23,17 @@ open4d = "open4d._cli:main"
 tools  = ["trimesh"]
 metrics = ["scipy"]
 player = ["PyQt6", "pyqtgraph", "PyOpenGL", "pillow>=9", "scipy"]
-open3d = ["open3d>=0.19", "pillow>=9"]
+# 0.20 applies depth_scale to float depth, but its legacy TSDF integrator
+# still passes 1000 for images already in metres and silently extracts no mesh.
+open3d = ["open3d>=0.19,<0.20", "pillow>=9"]
 usd    = ["usd-core>=24.3"]
 torch  = ["torch"]
 klt    = ["torch", "trimesh", "zstd", "tqdm", "point-cloud-utils"]
 n4mc   = ["torch", "trimesh", "scikit-image", "point-cloud-utils"]
-qndf   = ["torch", "open3d>=0.19", "trimesh", "tqdm"]
+qndf   = ["torch", "open3d>=0.19,<0.20", "trimesh", "tqdm"]
 gaussians = ["plyfile"]
 dev    = ["build>=1.2", "pytest>=8", "scipy", "tomli>=2; python_version < '3.11'"]
-all    = ["plyfile", "trimesh", "PyQt6", "pyqtgraph", "PyOpenGL", "open3d>=0.19", "pillow>=9", "usd-core>=24.3", "scipy", "torch", "zstd", "tqdm", "point-cloud-utils", "scikit-image"]
+all    = ["plyfile", "trimesh", "PyQt6", "pyqtgraph", "PyOpenGL", "open3d>=0.19,<0.20", "pillow>=9", "usd-core>=24.3", "scipy", "torch", "zstd", "tqdm", "point-cloud-utils", "scikit-image"]
 
 [tool.setuptools]
 include-package-data = false