diff --git a/tests/agents/test_orchestration.py b/tests/agents/test_orchestration.py
new file mode 100644
index 0000000..fae162b
--- /dev/null
+++ b/tests/agents/test_orchestration.py
@@ -0,0 +1,353 @@
+"""
+Tests for orchestration module.
+
+Tests the multi-expert coordination infrastructure including
+delegation parsing, think updates, and result handling.
+"""
+import pytest
+from unittest.mock import AsyncMock, patch
+
+from src.agents.orchestration import (
+    OrchestrationContext,
+    parse_delegation_from_steward_note,
+    execute_delegation,
+    orchestrate_with_think_updates,
+    extract_delegation_context,
+)
+from src.agents.delegation import DelegationTask, DelegationResult
+
+
+@pytest.mark.unit
+class TestParseDelegation:
+    """Tests for parsing delegation from Steward's note."""
+
+    def test_parse_librarian_create(self):
+        """Test parsing librarian create delegation."""
+        note = """DELEGATE: librarian to create a wiki page about CI/CD pipelines
+REASON: User wants to document CI/CD concepts
+COMPLEXITY: moderate
+CONTEXT: none"""
+
+        task = parse_delegation_from_steward_note(note)
+
+        assert task is not None
+        assert task.expert_name == "librarian"
+        assert "create a wiki page about CI/CD pipelines" in task.task
+
+    def test_parse_librarian_search(self):
+        """Test parsing librarian search delegation."""
+        note = """DELEGATE: librarian to search for information about Docker networking
+REASON: User needs Docker documentation
+COMPLEXITY: simple"""
+
+        task = parse_delegation_from_steward_note(note)
+
+        assert task is not None
+        assert task.expert_name == "librarian"
+        assert "search for information about Docker networking" in task.task
+
+    def test_parse_no_delegation(self):
+        """Test parsing when no delegation needed."""
+        note = """DELEGATE: none (conversational response only)
+REASON: Simple greeting requires no tools
+COMPLEXITY: simple"""
+
+        task = parse_delegation_from_steward_note(note)
+
+        assert task is None
+
+    def test_parse_tatlock_core(self):
+        """Test parsing tatlock_core delegation."""
+        note = """DELEGATE: tatlock_core to calculate the result
+REASON: Math calculation needed
+COMPLEXITY: simple"""
+
+        task = parse_delegation_from_steward_note(note)
+
+        assert task is not None
+        assert task.expert_name == "tatlock_core"
+        assert "calculate the result" in task.task
+
+    def test_parse_case_insensitive(self):
+        """Test parsing is case insensitive."""
+        note = """delegate: LIBRARIAN to search docs
+reason: Research query"""
+
+        task = parse_delegation_from_steward_note(note)
+
+        assert task is not None
+        assert task.expert_name == "librarian"
+
+    def test_parse_missing_delegate(self):
+        """Test parsing when DELEGATE line is missing."""
+        note = """REASON: This has no delegation
+COMPLEXITY: simple"""
+
+        task = parse_delegation_from_steward_note(note)
+
+        assert task is None
+
+
+@pytest.mark.unit
+class TestExtractDelegationContext:
+    """Tests for extracting context from Steward's note."""
+
+    def test_extract_all_fields(self):
+        """Test extracting all context fields."""
+        note = """DELEGATE: librarian to create wiki page
+REASON: User wants documentation
+COMPLEXITY: moderate
+CONTEXT: Related to previous discussion about DevOps"""
+
+        context = extract_delegation_context(note)
+
+        assert context["reason"] == "User wants documentation"
+        assert context["complexity"] == "moderate"
+        assert "Related to previous discussion" in context["context"]
+
+    def test_extract_partial_fields(self):
+        """Test extracting when some fields missing."""
+        note = """DELEGATE: librarian to search
+REASON: Research query
+COMPLEXITY: simple"""
+
+        context = extract_delegation_context(note)
+
+        assert context["reason"] == "Research query"
+        assert context["complexity"] == "simple"
+        assert context["context"] == ""
+
+    def test_extract_empty_note(self):
+        """Test extracting from empty note."""
+        context = extract_delegation_context("")
+
+        assert context["reason"] == ""
+        assert context["complexity"] == ""
+        assert context["context"] == ""
+
+
+@pytest.mark.unit
+class TestExecuteDelegation:
+    """Tests for executing delegation tasks."""
+
+    @pytest.mark.asyncio
+    async def test_execute_librarian_delegation(self):
+        """Test executing delegation to librarian."""
+        task = DelegationTask(
+            expert_name="librarian",
+            task="search for Docker docs",
+            context="User learning Docker",
+        )
+
+        mock_result = DelegationResult(
+            expert_name="librarian",
+            task="search for Docker docs",
+            success=True,
+            output="Found Docker documentation...",
+        )
+
+        with patch(
+            "src.agents.orchestration.delegate_to_librarian",
+            new_callable=AsyncMock,
+            return_value=mock_result,
+        ) as mock_delegate:
+            result = await execute_delegation(task)
+
+            mock_delegate.assert_called_once_with(
+                task="search for Docker docs",
+                context="User learning Docker",
+            )
+
+            assert result.success is True
+            assert "Docker" in result.output
+
+    @pytest.mark.asyncio
+    async def test_execute_unknown_expert(self):
+        """Test executing delegation to unknown expert."""
+        task = DelegationTask(
+            expert_name="unknown_expert",
+            task="do something",
+        )
+
+        result = await execute_delegation(task)
+
+        assert result.success is False
+        assert "Unknown expert" in result.error
+
+
+@pytest.mark.unit
+class TestOrchestrateWithThinkUpdates:
+    """Tests for orchestration with think updates."""
+
+    @pytest.mark.asyncio
+    async def test_orchestrate_emits_think_before_delegation(self):
+        """Test that think update is emitted before delegation."""
+        mock_result = DelegationResult(
+            expert_name="librarian",
+            task="search docs",
+            success=True,
+            output="Found results",
+        )
+
+        with patch(
+            "src.agents.orchestration.delegate_to_librarian",
+            new_callable=AsyncMock,
+            return_value=mock_result,
+        ):
+            updates = []
+            async for update in orchestrate_with_think_updates(
+                user_message="Search for Docker info",
+                steward_note="DELEGATE: librarian to search for Docker info",
+            ):
+                updates.append(update)
+
+            # First update should be think tag about consulting
+            assert any("<think>" in u and "Consulting" in u for u in updates)
+
+    @pytest.mark.asyncio
+    async def test_orchestrate_emits_think_after_delegation(self):
+        """Test that think update is emitted after delegation."""
+        mock_result = DelegationResult(
+            expert_name="librarian",
+            task="search docs",
+            success=True,
+            output="Found results",
+        )
+
+        with patch(
+            "src.agents.orchestration.delegate_to_librarian",
+            new_callable=AsyncMock,
+            return_value=mock_result,
+        ):
+            updates = []
+            async for update in orchestrate_with_think_updates(
+                user_message="Search for Docker info",
+                steward_note="DELEGATE: librarian to search for Docker info",
+            ):
+                updates.append(update)
+
+            # Should have think tag about completion
+            assert any("<think>" in u and "completed" in u for u in updates)
+
+    @pytest.mark.asyncio
+    async def test_orchestrate_yields_expert_output(self):
+        """Test that expert output is yielded."""
+        mock_result = DelegationResult(
+            expert_name="librarian",
+            task="search docs",
+            success=True,
+            output="Found Docker documentation with networking details",
+        )
+
+        with patch(
+            "src.agents.orchestration.delegate_to_librarian",
+            new_callable=AsyncMock,
+            return_value=mock_result,
+        ):
+            updates = []
+            async for update in orchestrate_with_think_updates(
+                user_message="Search for Docker info",
+                steward_note="DELEGATE: librarian to search for Docker info",
+            ):
+                updates.append(update)
+
+            # Should include expert output
+            all_output = "".join(updates)
+            assert "Docker documentation" in all_output
+
+    @pytest.mark.asyncio
+    async def test_orchestrate_handles_delegation_failure(self):
+        """Test that delegation failure emits warning think update."""
+        mock_result = DelegationResult(
+            expert_name="librarian",
+            task="search docs",
+            success=False,
+            output="",
+            error="Connection timeout",
+        )
+
+        with patch(
+            "src.agents.orchestration.delegate_to_librarian",
+            new_callable=AsyncMock,
+            return_value=mock_result,
+        ):
+            updates = []
+            async for update in orchestrate_with_think_updates(
+                user_message="Search for info",
+                steward_note="DELEGATE: librarian to search",
+            ):
+                updates.append(update)
+
+            # Should have warning think update
+            all_output = "".join(updates)
+            assert "⚠️" in all_output or "issue" in all_output.lower()
+
+    @pytest.mark.asyncio
+    async def test_orchestrate_no_delegation_returns_empty(self):
+        """Test that no delegation yields nothing."""
+        updates = []
+        async for update in orchestrate_with_think_updates(
+            user_message="Hello",
+            steward_note="DELEGATE: none (conversational)",
+        ):
+            updates.append(update)
+
+        assert len(updates) == 0
+
+    @pytest.mark.asyncio
+    async def test_orchestrate_with_preparsed_task(self):
+        """Test orchestration with pre-parsed delegation task."""
+        task = DelegationTask(
+            expert_name="librarian",
+            task="create wiki page",
+        )
+
+        mock_result = DelegationResult(
+            expert_name="librarian",
+            task="create wiki page",
+            success=True,
+            output="Wiki page created",
+        )
+
+        with patch(
+            "src.agents.orchestration.delegate_to_librarian",
+            new_callable=AsyncMock,
+            return_value=mock_result,
+        ):
+            updates = []
+            async for update in orchestrate_with_think_updates(
+                user_message="Create wiki page",
+                steward_note="",  # Empty note since task is pre-parsed
+                delegation_task=task,
+            ):
+                updates.append(update)
+
+            assert len(updates) > 0
+            all_output = "".join(updates)
+            assert "Wiki page created" in all_output
+
+
+@pytest.mark.unit
+class TestOrchestrationContext:
+    """Tests for OrchestrationContext dataclass."""
+
+    def test_context_creation(self):
+        """Test creating orchestration context."""
+        ctx = OrchestrationContext(
+            user_message="Test message",
+            steward_note="Test note",
+            conversation_id="conv_123",
+        )
+
+        assert ctx.user_message == "Test message"
+        assert ctx.steward_note == "Test note"
+        assert ctx.conversation_id == "conv_123"
+
+    def test_context_defaults(self):
+        """Test orchestration context default values."""
+        ctx = OrchestrationContext(
+            user_message="Test",
+            steward_note="Note",
+        )
+
+        assert ctx.conversation_id is None