diff --git a/src/modeldock/__init__.py b/src/modeldock/__init__.py
index 04bc8aa..467744b 100644
--- a/src/modeldock/__init__.py
+++ b/src/modeldock/__init__.py
@@ -54,7 +54,7 @@ def configure(
 def load(name: str, backend: Optional[str] = None, auto_install: Optional[bool] = None) -> Any:
     """Auto-install if missing, then return a ready-to-use client."""
     if backend is not None:
-        return _manager().load(name, auto_install=auto_install)
+        return Manager(backend=backend).load(name, auto_install=auto_install)
     return _manager().load(name, auto_install=auto_install)
 
 
@@ -90,29 +90,50 @@ def recommend(task: str) -> List[Any]:
 
 def install(name: str, backend: Optional[str] = None) -> ModelRef:
     """Explicit download."""
+    if backend is not None:
+        return Manager(backend=backend).install(name)
     return _manager().install(name)
 
 
 def install_category(category: str, backend: Optional[str] = None) -> List[ModelRef]:
     """Bulk install by category."""
+    if backend is not None:
+        return Manager(backend=backend).install_category(category)
     return _manager().install_category(category)
 
 
 def update(name: str, backend: Optional[str] = None) -> ModelRef:
     """Pull a newer tag."""
+    if backend is not None:
+        return Manager(backend=backend).update(name)
     return _manager().update(name)
 
 
 def remove(name: str, backend: Optional[str] = None) -> None:
     """Uninstall."""
+    if backend is not None:
+        Manager(backend=backend).remove(name)
+        return
     _manager().remove(name)
 
 
 def verify(name: str, backend: Optional[str] = None) -> bool:
     """Integrity check."""
+    if backend is not None:
+        return Manager(backend=backend).verify(name)
     return _manager().verify(name)
 
 
+def run(name: str, prompt: Optional[str] = None, backend: Optional[str] = None, **opts: Any) -> Any:
+    """Run an interactive session for a model in the active runtime.
+
+    With ``prompt`` runs a single completion; without it, drops into a REPL.
+    """
+    if backend is not None:
+        return Manager(backend=backend).run(name, prompt=prompt, **opts)
+    return _manager().run(name, prompt=prompt, **opts)
+
+
 class _CacheFacade:
     """Thin facade exposing cache operations on the singleton."""
 
@@ -167,6 +188,7 @@ def Manager(
     "update",
     "remove",
     "verify",
+    "run",
     "cache",
     "configure",
     "Manager",
diff --git a/tests/unit/test_sdk_api.py b/tests/unit/test_sdk_api.py
index 682d98f..681e0a1 100644
--- a/tests/unit/test_sdk_api.py
+++ b/tests/unit/test_sdk_api.py
@@ -115,3 +115,37 @@ def test_sdk_load_via_fake_manager() -> None:
 def test_modelref_and_backend_exports() -> None:
     assert md.ModelRef.parse("llama3:8b").qualified_name() == "llama3:8b"
     assert md.RuntimeBackend.from_value("ollama") == RuntimeBackend.OLLAMA
+
+
+def test_sdk_run_via_fake_manager() -> None:
+    from tests.conftest import FakeCache, FakeRegistry, FakeRuntime
+
+    runtime = FakeRuntime()
+    mgr = md.ModelManager(runtime=runtime, registry=FakeRegistry(), cache=FakeCache())
+    result = mgr.run("llama3", prompt="hi")
+    assert result.success is True
+
+
+def test_sdk_run_exported() -> None:
+    assert hasattr(md, "run")
+    assert "run" in md.__all__
+
+
+def test_load_routes_backend_to_manager() -> None:
+    from modeldock.domain.model import RuntimeBackend
+
+    # Manager(backend=...) sets the active backend without touching a runtime.
+    mgr = md.Manager(backend="ollama")
+    assert mgr._backend == RuntimeBackend.OLLAMA
+
+
+def test_info_surfaces_installed_tags_for_catalog_model() -> None:
+    from modeldock.domain.model import ModelRef
+    from tests.conftest import FakeCache, FakeRegistry, FakeRuntime
+
+    ref = ModelRef.parse("llama3:latest")
+    runtime = FakeRuntime(installed=[ref])
+    mgr = md.ModelManager(runtime=runtime, registry=FakeRegistry(), cache=FakeCache())
+    info = mgr.info("llama3")
+    assert info.installed is True
+    assert info.installed_tags == ["latest"]