@@ -41,7 +41,7 @@ A `feast-mcp` console script is also installed. It is equivalent to `feast mcp`,
 
 **Server options:**
 * `--transport`: MCP transport to serve: `stdio`, `http`, `streamable-http`, or `sse` (default: `stdio`)
-* `--host`: Bind address for HTTP transports (default: `0.0.0.0`)
+* `--host`: Bind address for HTTP transports (default: `0.0.0.0`). Use `::` to serve both IPv6 and IPv4 clients; it falls back to `0.0.0.0` where IPv6 is unavailable.
 * `--port`: Bind port for HTTP transports (default: 8000)
 * `--workers`: Run under gunicorn with this many workers. Not supported by the `sse` transport
 
 
@@ -109,7 +109,25 @@ def _run_uvicorn(mcp: FastMCP, cfg: Config) -> None:
     import uvicorn
 
     app = _build_http_app(mcp, cfg)
-    uvicorn.run(app, host=cfg.server.host, port=cfg.server.port)
+    if cfg.server.host == "::":
+        # uvicorn.run(host="::") binds IPv6-only, which drops IPv4 clients
+        # (see feast.utils._make_dual_stack_socket).
+        from feast.utils import _make_dual_stack_socket
+
+        sock = _make_dual_stack_socket(cfg.server.port)
+        uvicorn.Server(uvicorn.Config(app)).run(sockets=[sock])
+    else:
+        uvicorn.run(app, host=cfg.server.host, port=cfg.server.port)
+
+
+def _gunicorn_bind(cfg: Config) -> str:
+    """Bind address for gunicorn: ``::`` becomes the bracketed ``[::]`` (dual-stack), or ``0.0.0.0`` where IPv6 is unavailable."""
+    host = cfg.server.host
+    if host == "::":
+        from feast.utils import _ipv6_available
+
+        host = "[::]" if _ipv6_available() else "0.0.0.0"
+    return f"{host}:{cfg.server.port}"
 
 
 def _run_gunicorn(mcp: FastMCP, cfg: Config) -> None:
@@ -119,7 +137,7 @@ def _run_gunicorn(mcp: FastMCP, cfg: Config) -> None:
 
     class FeastMCPApplication(BaseApplication):
         def load_config(self) -> None:
-            self.cfg.set("bind", f"{cfg.server.host}:{cfg.server.port}")
+            self.cfg.set("bind", _gunicorn_bind(cfg))
             self.cfg.set("workers", cfg.server.workers)
             self.cfg.set("worker_class", "uvicorn.workers.UvicornWorker")
             self.cfg.set("accesslog", "-")
@@ -225,7 +243,7 @@ def run_server(
 @click.option(
     "--host",
     default=None,
-    help="Bind address for HTTP transports.  [default: 0.0.0.0]",
+    help="Bind address for HTTP transports; '::' serves IPv6 and IPv4.  [default: 0.0.0.0]",
 )
 @click.option(
     "--port",
 
@@ -0,0 +1,51 @@
+"""IPv6 / dual-stack binds for the standalone MCP server (host ``::``)."""
+
+from types import SimpleNamespace
+from unittest.mock import MagicMock, patch
+
+import pytest
+
+from feast.mcp.server import _gunicorn_bind, _run_uvicorn
+
+
+def _cfg(host: str, port: int = 8000):
+    return SimpleNamespace(server=SimpleNamespace(host=host, port=port))
+
+
+@patch("feast.mcp.server._build_http_app")
+@patch("uvicorn.run")
+@patch("uvicorn.Server")
+@patch("uvicorn.Config")
+def test_uvicorn_dual_stack_binds_prebuilt_socket(
+    mock_config, mock_server, mock_run, _mock_app
+):
+    """uvicorn.run(host="::") binds IPv6-only and drops IPv4 clients."""
+    sock = MagicMock()
+    with patch("feast.utils._make_dual_stack_socket", return_value=sock) as make:
+        _run_uvicorn(MagicMock(), _cfg("::"))
+
+    make.assert_called_once_with(8000)
+    mock_server.return_value.run.assert_called_once_with(sockets=[sock])
+    mock_run.assert_not_called()
+
+
+@patch("feast.mcp.server._build_http_app")
+@patch("uvicorn.run")
+def test_uvicorn_other_hosts_use_plain_run(mock_run, mock_app):
+    _run_uvicorn(MagicMock(), _cfg("0.0.0.0"))
+
+    mock_run.assert_called_once_with(mock_app.return_value, host="0.0.0.0", port=8000)
+
+
+@pytest.mark.parametrize(
+    "host, ipv6, want",
+    [
+        ("::", True, "[::]:8000"),
+        ("::", False, "0.0.0.0:8000"),
+        ("0.0.0.0", True, "0.0.0.0:8000"),
+        ("127.0.0.1", False, "127.0.0.1:8000"),
+    ],
+)
+def test_gunicorn_bind(host, ipv6, want):
+    with patch("feast.utils._ipv6_available", return_value=ipv6):
+        assert _gunicorn_bind(_cfg(host)) == want