diff --git a/multi_agent/definitions.py b/multi_agent/definitions.py
new file mode 100644
index 0000000..362f1e0
--- /dev/null
+++ b/multi_agent/definitions.py
@@ -0,0 +1,10 @@
+"""Proxy -- re-exports agent definitions from multi_agent.subagent."""
+from .subagent import (
+    AgentDefinition,
+    get_agent_definition,
+    load_agent_definitions,
+    _parse_agent_md,
+    _BUILTIN_AGENTS,
+)
+
+__all__ = ["AgentDefinition", "get_agent_definition", "load_agent_definitions"]
diff --git a/multi_agent/manager.py b/multi_agent/manager.py
new file mode 100644
index 0000000..4252fb9
--- /dev/null
+++ b/multi_agent/manager.py
@@ -0,0 +1,4 @@
+"""Proxy -- re-exports SubAgentManager from multi_agent.subagent."""
+from .subagent import SubAgentManager
+
+__all__ = ["SubAgentManager"]
diff --git a/multi_agent/task.py b/multi_agent/task.py
new file mode 100644
index 0000000..5d478ed
--- /dev/null
+++ b/multi_agent/task.py
@@ -0,0 +1,11 @@
+"""Proxy -- re-exports task classes from multi_agent.subagent."""
+from .subagent import (
+    SubAgentTask,
+    _extract_final_text,
+    _git_root,
+    _create_worktree,
+    _remove_worktree,
+    _agent_run,
+)
+
+__all__ = ["SubAgentTask"]
diff --git a/tests/test_multi_agent_split.py b/tests/test_multi_agent_split.py
new file mode 100644
index 0000000..12a0167
--- /dev/null
+++ b/tests/test_multi_agent_split.py
@@ -0,0 +1,55 @@
+"""Tests for multi_agent package split import paths (PR #51)."""
+from multi_agent.subagent import (
+    AgentDefinition,
+    SubAgentManager,
+    SubAgentTask,
+    get_agent_definition,
+    load_agent_definitions,
+    _extract_final_text,
+)
+
+
+class TestSplitImportPaths:
+    def test_definitions_reexports(self):
+        from multi_agent.definitions import (
+            AgentDefinition as AD,
+            get_agent_definition as gad,
+            load_agent_definitions as lad,
+        )
+        assert AD is AgentDefinition
+        assert gad is get_agent_definition
+        assert lad is load_agent_definitions
+
+    def test_manager_reexports(self):
+        from multi_agent.manager import SubAgentManager as SAM
+        assert SAM is SubAgentManager
+
+    def test_task_reexports(self):
+        from multi_agent.task import SubAgentTask as SAT
+        from multi_agent.task import _extract_final_text as eft
+        assert SAT is SubAgentTask
+        assert eft is _extract_final_text
+
+    def test_backward_compat_root_shim(self):
+        import subagent
+        assert hasattr(subagent, 'SubAgentManager')
+        assert hasattr(subagent, 'SubAgentTask')
+        assert hasattr(subagent, 'AgentDefinition')
+
+
+class TestAgentDefinitionsViaProxy:
+    def test_builtin_agents(self):
+        from multi_agent.definitions import load_agent_definitions
+        agents = load_agent_definitions()
+        for name in ("general-purpose", "coder", "reviewer", "researcher", "tester"):
+            assert name in agents
+
+    def test_get_valid(self):
+        from multi_agent.definitions import get_agent_definition
+        defn = get_agent_definition("coder")
+        assert defn is not None
+        assert defn.name == "coder"
+
+    def test_get_unknown_returns_none(self):
+        from multi_agent.definitions import get_agent_definition
+        assert get_agent_definition("nonexistent_xyz") is None