diff --git a/python/src/mcp_server/features/documents/document_tools.py b/python/src/mcp_server/features/documents/document_tools.py
index e14d07a..2656206 100644
--- a/python/src/mcp_server/features/documents/document_tools.py
+++ b/python/src/mcp_server/features/documents/document_tools.py
@@ -144,7 +144,11 @@ def register_document_tools(mcp: FastMCP):
             timeout = get_default_timeout()
 
             async with httpx.AsyncClient(timeout=timeout) as client:
-                response = await client.get(urljoin(api_url, f"/api/projects/{project_id}/docs"))
+                # Pass include_content=False for lightweight response
+                response = await client.get(
+                    urljoin(api_url, f"/api/projects/{project_id}/docs"),
+                    params={"include_content": False}
+                )
 
                 if response.status_code == 200:
                     result = response.json()
diff --git a/python/src/mcp_server/features/projects/project_tools.py b/python/src/mcp_server/features/projects/project_tools.py
index 367e932..db4819f 100644
--- a/python/src/mcp_server/features/projects/project_tools.py
+++ b/python/src/mcp_server/features/projects/project_tools.py
@@ -175,7 +175,11 @@ def register_project_tools(mcp: FastMCP):
             timeout = get_default_timeout()
 
             async with httpx.AsyncClient(timeout=timeout) as client:
-                response = await client.get(urljoin(api_url, "/api/projects"))
+                # CRITICAL: Pass include_content=False for lightweight response
+                response = await client.get(
+                    urljoin(api_url, "/api/projects"),
+                    params={"include_content": False}
+                )
 
                 if response.status_code == 200:
                     projects = response.json()
diff --git a/python/src/server/api_routes/projects_api.py b/python/src/server/api_routes/projects_api.py
index 4d97ba3..3a735a8 100644
--- a/python/src/server/api_routes/projects_api.py
+++ b/python/src/server/api_routes/projects_api.py
@@ -9,7 +9,9 @@ Handles:
 """
 
 import asyncio
+import json
 import secrets
+import sys
 from typing import Any
 
 from fastapi import APIRouter, HTTPException
@@ -74,23 +76,49 @@ class CreateTaskRequest(BaseModel):
 
 
 @router.get("/projects")
-async def list_projects():
-    """List all projects."""
+async def list_projects(include_content: bool = True):
+    """
+    List all projects.
+    
+    Args:
+        include_content: If True (default), returns full project content.
+                        If False, returns lightweight metadata with statistics.
+    """
     try:
-        logfire.info("Listing all projects")
+        logfire.info(f"Listing all projects | include_content={include_content}")
 
-        # Use ProjectService to get projects
+        # Use ProjectService to get projects with include_content parameter
         project_service = ProjectService()
-        success, result = project_service.list_projects()
+        success, result = project_service.list_projects(include_content=include_content)
 
         if not success:
             raise HTTPException(status_code=500, detail=result)
 
-        # Use SourceLinkingService to format projects with sources
-        source_service = SourceLinkingService()
-        formatted_projects = source_service.format_projects_with_sources(result["projects"])
+        # Only format with sources if we have full content
+        if include_content:
+            # Use SourceLinkingService to format projects with sources
+            source_service = SourceLinkingService()
+            formatted_projects = source_service.format_projects_with_sources(result["projects"])
+        else:
+            # Lightweight response doesn't need source formatting
+            formatted_projects = result["projects"]
 
-        logfire.info(f"Projects listed successfully | count={len(formatted_projects)}")
+        # Monitor response size for optimization validation
+        response_json = json.dumps(formatted_projects)
+        response_size = len(response_json)
+        
+        # Log response metrics
+        logfire.info(
+            f"Projects listed successfully | count={len(formatted_projects)} | "
+            f"size_bytes={response_size} | include_content={include_content}"
+        )
+        
+        # Warning for large responses (>10KB)
+        if response_size > 10000:
+            logfire.warning(
+                f"Large response size detected | size_bytes={response_size} | "
+                f"include_content={include_content} | project_count={len(formatted_projects)}"
+            )
 
         return formatted_projects
 
@@ -473,11 +501,11 @@ async def get_project_features(project_id: str):
 
 
 @router.get("/projects/{project_id}/tasks")
-async def list_project_tasks(project_id: str, include_archived: bool = False):
+async def list_project_tasks(project_id: str, include_archived: bool = False, exclude_large_fields: bool = False):
     """List all tasks for a specific project. By default, filters out archived tasks."""
     try:
         logfire.info(
-            f"Listing project tasks | project_id={project_id} | include_archived={include_archived}"
+            f"Listing project tasks | project_id={project_id} | include_archived={include_archived} | exclude_large_fields={exclude_large_fields}"
         )
 
         # Use TaskService to list tasks
@@ -485,6 +513,7 @@ async def list_project_tasks(project_id: str, include_archived: bool = False):
         success, result = task_service.list_tasks(
             project_id=project_id,
             include_closed=True,  # Get all tasks, we'll filter archived separately
+            exclude_large_fields=exclude_large_fields,
         )
 
         if not success:
@@ -571,6 +600,7 @@ async def list_tasks(
             project_id=project_id,
             status=status,
             include_closed=include_closed,
+            exclude_large_fields=exclude_large_fields,
         )
 
         if not success:
@@ -591,8 +621,8 @@ async def list_tasks(
         end_idx = start_idx + per_page
         paginated_tasks = tasks[start_idx:end_idx]
 
-        # Return paginated response
-        return {
+        # Prepare response
+        response = {
             "tasks": paginated_tasks,
             "pagination": {
                 "total": len(tasks),
@@ -601,6 +631,25 @@ async def list_tasks(
                 "pages": (len(tasks) + per_page - 1) // per_page,
             },
         }
+        
+        # Monitor response size for optimization validation
+        response_json = json.dumps(response)
+        response_size = len(response_json)
+        
+        # Log response metrics
+        logfire.info(
+            f"Tasks listed successfully | count={len(paginated_tasks)} | "
+            f"size_bytes={response_size} | exclude_large_fields={exclude_large_fields}"
+        )
+        
+        # Warning for large responses (>10KB)
+        if response_size > 10000:
+            logfire.warning(
+                f"Large task response size | size_bytes={response_size} | "
+                f"exclude_large_fields={exclude_large_fields} | task_count={len(paginated_tasks)}"
+            )
+        
+        return response
 
     except HTTPException:
         raise
@@ -795,14 +844,23 @@ async def mcp_update_task_status_with_socketio(task_id: str, status: str):
 
 
 @router.get("/projects/{project_id}/docs")
-async def list_project_documents(project_id: str):
-    """List all documents for a specific project."""
+async def list_project_documents(project_id: str, include_content: bool = False):
+    """
+    List all documents for a specific project.
+    
+    Args:
+        project_id: Project UUID
+        include_content: If True, includes full document content.
+                        If False (default), returns metadata only.
+    """
     try:
-        logfire.info(f"Listing documents for project | project_id={project_id}")
+        logfire.info(
+            f"Listing documents for project | project_id={project_id} | include_content={include_content}"
+        )
 
         # Use DocumentService to list documents
         document_service = DocumentService()
-        success, result = document_service.list_documents(project_id)
+        success, result = document_service.list_documents(project_id, include_content=include_content)
 
         if not success:
             if "not found" in result.get("error", "").lower():
@@ -811,7 +869,7 @@ async def list_project_documents(project_id: str):
                 raise HTTPException(status_code=500, detail=result)
 
         logfire.info(
-            f"Documents listed successfully | project_id={project_id} | count={result.get('total_count', 0)}"
+            f"Documents listed successfully | project_id={project_id} | count={result.get('total_count', 0)} | lightweight={not include_content}"
         )
 
         return result
diff --git a/python/src/server/services/projects/document_service.py b/python/src/server/services/projects/document_service.py
index cd206e0..020ec30 100644
--- a/python/src/server/services/projects/document_service.py
+++ b/python/src/server/services/projects/document_service.py
@@ -96,10 +96,15 @@ class DocumentService:
             logger.error(f"Error adding document: {e}")
             return False, {"error": f"Error adding document: {str(e)}"}
 
-    def list_documents(self, project_id: str) -> tuple[bool, dict[str, Any]]:
+    def list_documents(self, project_id: str, include_content: bool = False) -> tuple[bool, dict[str, Any]]:
         """
         List all documents in a project's docs JSONB field.
 
+        Args:
+            project_id: The project ID
+            include_content: If True, includes full document content.
+                           If False (default), returns metadata only.
+
         Returns:
             Tuple of (success, result_dict)
         """
@@ -116,20 +121,28 @@ class DocumentService:
 
             docs = response.data[0].get("docs", [])
 
-            # Format documents for response (exclude full content for listing)
+            # Format documents for response
             documents = []
             for doc in docs:
-                documents.append({
-                    "id": doc.get("id"),
-                    "document_type": doc.get("document_type"),
-                    "title": doc.get("title"),
-                    "status": doc.get("status"),
-                    "version": doc.get("version"),
-                    "tags": doc.get("tags", []),
-                    "author": doc.get("author"),
-                    "created_at": doc.get("created_at"),
-                    "updated_at": doc.get("updated_at"),
-                })
+                if include_content:
+                    # Return full document
+                    documents.append(doc)
+                else:
+                    # Return metadata only
+                    documents.append({
+                        "id": doc.get("id"),
+                        "document_type": doc.get("document_type"),
+                        "title": doc.get("title"),
+                        "status": doc.get("status"),
+                        "version": doc.get("version"),
+                        "tags": doc.get("tags", []),
+                        "author": doc.get("author"),
+                        "created_at": doc.get("created_at"),
+                        "updated_at": doc.get("updated_at"),
+                        "stats": {
+                            "content_size": len(str(doc.get("content", {})))
+                        }
+                    })
 
             return True, {
                 "project_id": project_id,
diff --git a/python/src/server/services/projects/project_service.py b/python/src/server/services/projects/project_service.py
index c407b0b..ff88784 100644
--- a/python/src/server/services/projects/project_service.py
+++ b/python/src/server/services/projects/project_service.py
@@ -73,35 +73,73 @@ class ProjectService:
             logger.error(f"Error creating project: {e}")
             return False, {"error": f"Database error: {str(e)}"}
 
-    def list_projects(self) -> tuple[bool, dict[str, Any]]:
+    def list_projects(self, include_content: bool = True) -> tuple[bool, dict[str, Any]]:
         """
         List all projects.
 
+        Args:
+            include_content: If True (default), includes docs, features, data fields.
+                           If False, returns lightweight metadata only with counts.
+
         Returns:
             Tuple of (success, result_dict)
         """
         try:
-            response = (
-                self.supabase_client.table("archon_projects")
-                .select("*")
-                .order("created_at", desc=True)
-                .execute()
-            )
+            if include_content:
+                # Current behavior - maintain backward compatibility
+                response = (
+                    self.supabase_client.table("archon_projects")
+                    .select("*")
+                    .order("created_at", desc=True)
+                    .execute()
+                )
 
-            projects = []
-            for project in response.data:
-                projects.append({
-                    "id": project["id"],
-                    "title": project["title"],
-                    "github_repo": project.get("github_repo"),
-                    "created_at": project["created_at"],
-                    "updated_at": project["updated_at"],
-                    "pinned": project.get("pinned", False),
-                    "description": project.get("description", ""),
-                    "docs": project.get("docs", []),
-                    "features": project.get("features", []),
-                    "data": project.get("data", []),
-                })
+                projects = []
+                for project in response.data:
+                    projects.append({
+                        "id": project["id"],
+                        "title": project["title"],
+                        "github_repo": project.get("github_repo"),
+                        "created_at": project["created_at"],
+                        "updated_at": project["updated_at"],
+                        "pinned": project.get("pinned", False),
+                        "description": project.get("description", ""),
+                        "docs": project.get("docs", []),
+                        "features": project.get("features", []),
+                        "data": project.get("data", []),
+                    })
+            else:
+                # Lightweight response for MCP - fetch all data but only return metadata + stats
+                # FIXED: N+1 query problem - now using single query
+                response = (
+                    self.supabase_client.table("archon_projects")
+                    .select("*")  # Fetch all fields in single query
+                    .order("created_at", desc=True)
+                    .execute()
+                )
+
+                projects = []
+                for project in response.data:
+                    # Calculate counts from fetched data (no additional queries)
+                    docs_count = len(project.get("docs", []))
+                    features_count = len(project.get("features", []))
+                    has_data = bool(project.get("data", []))
+                    
+                    # Return only metadata + stats, excluding large JSONB fields
+                    projects.append({
+                        "id": project["id"],
+                        "title": project["title"],
+                        "github_repo": project.get("github_repo"),
+                        "created_at": project["created_at"],
+                        "updated_at": project["updated_at"],
+                        "pinned": project.get("pinned", False),
+                        "description": project.get("description", ""),
+                        "stats": {
+                            "docs_count": docs_count,
+                            "features_count": features_count,
+                            "has_data": has_data
+                        }
+                    })
 
             return True, {"projects": projects, "total_count": len(projects)}
 
diff --git a/python/src/server/services/projects/task_service.py b/python/src/server/services/projects/task_service.py
index 1d8f450..9d82d0f 100644
--- a/python/src/server/services/projects/task_service.py
+++ b/python/src/server/services/projects/task_service.py
@@ -186,17 +186,36 @@ class TaskService:
             return False, {"error": f"Error creating task: {str(e)}"}
 
     def list_tasks(
-        self, project_id: str = None, status: str = None, include_closed: bool = False
+        self, 
+        project_id: str = None, 
+        status: str = None, 
+        include_closed: bool = False,
+        exclude_large_fields: bool = False
     ) -> tuple[bool, dict[str, Any]]:
         """
         List tasks with various filters.
 
+        Args:
+            project_id: Filter by project
+            status: Filter by status
+            include_closed: Include done tasks
+            exclude_large_fields: If True, excludes sources and code_examples fields
+
         Returns:
             Tuple of (success, result_dict)
         """
         try:
             # Start with base query
-            query = self.supabase_client.table("archon_tasks").select("*")
+            if exclude_large_fields:
+                # Select all fields except large JSONB ones
+                query = self.supabase_client.table("archon_tasks").select(
+                    "id, project_id, parent_task_id, title, description, "
+                    "status, assignee, task_order, feature, archived, "
+                    "archived_at, archived_by, created_at, updated_at, "
+                    "sources, code_examples"  # Still fetch for counting, but will process differently
+                )
+            else:
+                query = self.supabase_client.table("archon_tasks").select("*")
 
             # Track filters for debugging
             filters_applied = []
@@ -265,7 +284,7 @@ class TaskService:
 
             tasks = []
             for task in response.data:
-                tasks.append({
+                task_data = {
                     "id": task["id"],
                     "project_id": task["project_id"],
                     "title": task["title"],
@@ -276,7 +295,20 @@ class TaskService:
                     "feature": task.get("feature"),
                     "created_at": task["created_at"],
                     "updated_at": task["updated_at"],
-                })
+                }
+                
+                if not exclude_large_fields:
+                    # Include full JSONB fields
+                    task_data["sources"] = task.get("sources", [])
+                    task_data["code_examples"] = task.get("code_examples", [])
+                else:
+                    # Add counts instead of full content
+                    task_data["stats"] = {
+                        "sources_count": len(task.get("sources", [])),
+                        "code_examples_count": len(task.get("code_examples", []))
+                    }
+                
+                tasks.append(task_data)
 
             filter_info = []
             if project_id:
diff --git a/python/tests/test_token_optimization.py b/python/tests/test_token_optimization.py
new file mode 100644
index 0000000..ebc5ac0
--- /dev/null
+++ b/python/tests/test_token_optimization.py
@@ -0,0 +1,356 @@
+"""
+Test suite for token optimization changes.
+Ensures backward compatibility and validates token reduction.
+"""
+
+import json
+import pytest
+from unittest.mock import Mock, patch
+
+from src.server.services.projects import ProjectService
+from src.server.services.projects.task_service import TaskService
+from src.server.services.projects.document_service import DocumentService
+
+
+class TestProjectServiceOptimization:
+    """Test ProjectService with include_content parameter."""
+    
+    @patch('src.server.utils.get_supabase_client')
+    def test_list_projects_with_full_content(self, mock_supabase):
+        """Test backward compatibility - default returns full content."""
+        # Setup mock
+        mock_client = Mock()
+        mock_supabase.return_value = mock_client
+        
+        # Mock response with large JSONB fields
+        mock_response = Mock()
+        mock_response.data = [{
+            "id": "test-id",
+            "title": "Test Project",
+            "description": "Test Description",
+            "github_repo": "https://github.com/test/repo",
+            "docs": [{"id": "doc1", "content": {"large": "content" * 100}}],
+            "features": [{"feature1": "data"}],
+            "data": [{"key": "value"}],
+            "pinned": False,
+            "created_at": "2024-01-01",
+            "updated_at": "2024-01-01"
+        }]
+        
+        mock_table = Mock()
+        mock_select = Mock()
+        mock_order = Mock()
+        mock_order.execute.return_value = mock_response
+        mock_select.order.return_value = mock_order
+        mock_table.select.return_value = mock_select
+        mock_client.table.return_value = mock_table
+        
+        # Test
+        service = ProjectService(mock_client)
+        success, result = service.list_projects()  # Default include_content=True
+        
+        # Assertions
+        assert success
+        assert len(result["projects"]) == 1
+        assert "docs" in result["projects"][0]
+        assert "features" in result["projects"][0]
+        assert "data" in result["projects"][0]
+        
+        # Verify full content is returned
+        assert len(result["projects"][0]["docs"]) == 1
+        assert result["projects"][0]["docs"][0]["content"]["large"] is not None
+        
+        # Verify SELECT * was used
+        mock_table.select.assert_called_with("*")
+    
+    @patch('src.server.utils.get_supabase_client')
+    def test_list_projects_lightweight(self, mock_supabase):
+        """Test lightweight response excludes large fields."""
+        # Setup mock
+        mock_client = Mock()
+        mock_supabase.return_value = mock_client
+        
+        # Mock response with full data (after N+1 fix, we fetch all data)
+        mock_response = Mock()
+        mock_response.data = [{
+            "id": "test-id",
+            "title": "Test Project",
+            "description": "Test Description",
+            "github_repo": "https://github.com/test/repo",
+            "created_at": "2024-01-01",
+            "updated_at": "2024-01-01",
+            "pinned": False,
+            "docs": [{"id": "doc1"}, {"id": "doc2"}, {"id": "doc3"}],  # 3 docs
+            "features": [{"feature1": "data"}, {"feature2": "data"}],  # 2 features
+            "data": [{"key": "value"}]  # Has data
+        }]
+        
+        # Setup mock chain - now simpler after N+1 fix
+        mock_table = Mock()
+        mock_select = Mock()
+        mock_order = Mock()
+        
+        mock_order.execute.return_value = mock_response
+        mock_select.order.return_value = mock_order
+        mock_table.select.return_value = mock_select
+        mock_client.table.return_value = mock_table
+        
+        # Test
+        service = ProjectService(mock_client)
+        success, result = service.list_projects(include_content=False)
+        
+        # Assertions
+        assert success
+        assert len(result["projects"]) == 1
+        project = result["projects"][0]
+        
+        # Verify no large fields
+        assert "docs" not in project
+        assert "features" not in project
+        assert "data" not in project
+        
+        # Verify stats are present
+        assert "stats" in project
+        assert project["stats"]["docs_count"] == 3
+        assert project["stats"]["features_count"] == 2
+        assert project["stats"]["has_data"] is True
+        
+        # Verify SELECT * was used (after N+1 fix, we fetch all data in one query)
+        mock_table.select.assert_called_with("*")
+        assert mock_client.table.call_count == 1  # Only one query now!
+    
+    def test_token_reduction(self):
+        """Verify token count reduction."""
+        # Simulate full content response
+        full_content = {
+            "projects": [{
+                "id": "test",
+                "title": "Test",
+                "description": "Test Description",
+                "docs": [{"content": {"large": "x" * 10000}} for _ in range(5)],
+                "features": [{"data": "y" * 5000} for _ in range(3)],
+                "data": [{"values": "z" * 8000}]
+            }]
+        }
+        
+        # Simulate lightweight response
+        lightweight = {
+            "projects": [{
+                "id": "test",
+                "title": "Test",
+                "description": "Test Description",
+                "stats": {
+                    "docs_count": 5,
+                    "features_count": 3,
+                    "has_data": True
+                }
+            }]
+        }
+        
+        # Calculate approximate token counts (rough estimate: 1 token ≈ 4 chars)
+        full_tokens = len(json.dumps(full_content)) / 4
+        light_tokens = len(json.dumps(lightweight)) / 4
+        
+        reduction_percentage = (1 - light_tokens / full_tokens) * 100
+        
+        # Assert 95% reduction (allowing some margin)
+        assert reduction_percentage > 95, f"Token reduction is only {reduction_percentage:.1f}%"
+
+
+class TestTaskServiceOptimization:
+    """Test TaskService with exclude_large_fields parameter."""
+    
+    @patch('src.server.utils.get_supabase_client')
+    def test_list_tasks_with_large_fields(self, mock_supabase):
+        """Test backward compatibility - default includes large fields."""
+        mock_client = Mock()
+        mock_supabase.return_value = mock_client
+        
+        mock_response = Mock()
+        mock_response.data = [{
+            "id": "task-1",
+            "project_id": "proj-1",
+            "title": "Test Task",
+            "description": "Test Description",
+            "sources": [{"url": "http://example.com", "content": "large"}],
+            "code_examples": [{"code": "function() { /* large */ }"}],
+            "status": "todo",
+            "assignee": "User",
+            "task_order": 0,
+            "feature": None,
+            "created_at": "2024-01-01",
+            "updated_at": "2024-01-01"
+        }]
+        
+        # Setup mock chain
+        mock_table = Mock()
+        mock_select = Mock()
+        mock_or = Mock()
+        mock_order1 = Mock()
+        mock_order2 = Mock()
+        
+        mock_order2.execute.return_value = mock_response
+        mock_order1.order.return_value = mock_order2
+        mock_or.order.return_value = mock_order1
+        mock_select.neq().or_.return_value = mock_or
+        mock_table.select.return_value = mock_select
+        mock_client.table.return_value = mock_table
+        
+        service = TaskService(mock_client)
+        success, result = service.list_tasks()
+        
+        assert success
+        assert "sources" in result["tasks"][0]
+        assert "code_examples" in result["tasks"][0]
+    
+    @patch('src.server.utils.get_supabase_client')
+    def test_list_tasks_exclude_large_fields(self, mock_supabase):
+        """Test excluding large fields returns counts instead."""
+        mock_client = Mock()
+        mock_supabase.return_value = mock_client
+        
+        mock_response = Mock()
+        mock_response.data = [{
+            "id": "task-1",
+            "project_id": "proj-1",
+            "title": "Test Task",
+            "description": "Test Description",
+            "status": "todo",
+            "assignee": "User",
+            "task_order": 0,
+            "feature": None,
+            "sources": [1, 2, 3],  # Will be counted
+            "code_examples": [1, 2],  # Will be counted
+            "created_at": "2024-01-01",
+            "updated_at": "2024-01-01"
+        }]
+        
+        # Setup mock chain
+        mock_table = Mock()
+        mock_select = Mock()
+        mock_or = Mock()
+        mock_order1 = Mock()
+        mock_order2 = Mock()
+        
+        mock_order2.execute.return_value = mock_response
+        mock_order1.order.return_value = mock_order2
+        mock_or.order.return_value = mock_order1
+        mock_select.neq().or_.return_value = mock_or
+        mock_table.select.return_value = mock_select
+        mock_client.table.return_value = mock_table
+        
+        service = TaskService(mock_client)
+        success, result = service.list_tasks(exclude_large_fields=True)
+        
+        assert success
+        task = result["tasks"][0]
+        assert "sources" not in task
+        assert "code_examples" not in task
+        assert "stats" in task
+        assert task["stats"]["sources_count"] == 3
+        assert task["stats"]["code_examples_count"] == 2
+
+
+class TestDocumentServiceOptimization:
+    """Test DocumentService with include_content parameter."""
+    
+    @patch('src.server.utils.get_supabase_client')
+    def test_list_documents_metadata_only(self, mock_supabase):
+        """Test default returns metadata only."""
+        mock_client = Mock()
+        mock_supabase.return_value = mock_client
+        
+        mock_response = Mock()
+        mock_response.data = [{
+            "docs": [{
+                "id": "doc-1",
+                "title": "Test Doc",
+                "content": {"huge": "content" * 1000},
+                "document_type": "spec",
+                "status": "draft",
+                "version": "1.0",
+                "tags": ["test"],
+                "author": "Test Author"
+            }]
+        }]
+        
+        # Setup mock chain
+        mock_table = Mock()
+        mock_select = Mock()
+        mock_eq = Mock()
+        
+        mock_eq.execute.return_value = mock_response
+        mock_select.eq.return_value = mock_eq
+        mock_table.select.return_value = mock_select
+        mock_client.table.return_value = mock_table
+        
+        service = DocumentService(mock_client)
+        success, result = service.list_documents("project-1")  # Default include_content=False
+        
+        assert success
+        doc = result["documents"][0]
+        assert "content" not in doc
+        assert "stats" in doc
+        assert doc["stats"]["content_size"] > 0
+        assert doc["title"] == "Test Doc"
+    
+    @patch('src.server.utils.get_supabase_client')
+    def test_list_documents_with_content(self, mock_supabase):
+        """Test include_content=True returns full documents."""
+        mock_client = Mock()
+        mock_supabase.return_value = mock_client
+        
+        mock_response = Mock()
+        mock_response.data = [{
+            "docs": [{
+                "id": "doc-1",
+                "title": "Test Doc",
+                "content": {"huge": "content"},
+                "document_type": "spec"
+            }]
+        }]
+        
+        # Setup mock chain
+        mock_table = Mock()
+        mock_select = Mock()
+        mock_eq = Mock()
+        
+        mock_eq.execute.return_value = mock_response
+        mock_select.eq.return_value = mock_eq
+        mock_table.select.return_value = mock_select
+        mock_client.table.return_value = mock_table
+        
+        service = DocumentService(mock_client)
+        success, result = service.list_documents("project-1", include_content=True)
+        
+        assert success
+        doc = result["documents"][0]
+        assert "content" in doc
+        assert doc["content"]["huge"] == "content"
+
+
+class TestBackwardCompatibility:
+    """Ensure all changes are backward compatible."""
+    
+    def test_api_defaults_preserve_behavior(self):
+        """Test that API defaults maintain current behavior."""
+        # ProjectService default should include content
+        service = ProjectService(Mock())
+        # Check default parameter value
+        import inspect
+        sig = inspect.signature(service.list_projects)
+        assert sig.parameters['include_content'].default is True
+        
+        # DocumentService default should NOT include content
+        doc_service = DocumentService(Mock())
+        sig = inspect.signature(doc_service.list_documents)
+        assert sig.parameters['include_content'].default is False
+        
+        # TaskService default should NOT exclude fields
+        task_service = TaskService(Mock())
+        sig = inspect.signature(task_service.list_tasks)
+        assert sig.parameters['exclude_large_fields'].default is False
+
+
+if __name__ == "__main__":
+    pytest.main([__file__, "-v"])
\ No newline at end of file
diff --git a/python/tests/test_token_optimization_integration.py b/python/tests/test_token_optimization_integration.py
new file mode 100644
index 0000000..7d82caa
--- /dev/null
+++ b/python/tests/test_token_optimization_integration.py
@@ -0,0 +1,189 @@
+"""
+Integration tests to verify token optimization in running system.
+Run with: uv run pytest tests/test_token_optimization_integration.py -v
+"""
+
+import httpx
+import json
+import asyncio
+from typing import Dict, Any, Tuple
+
+
+async def measure_response_size(url: str, params: Dict[str, Any] = None) -> Tuple[int, int]:
+    """Measure response size and estimate token count."""
+    async with httpx.AsyncClient() as client:
+        try:
+            response = await client.get(url, params=params, timeout=10.0)
+            response_text = response.text
+            response_size = len(response_text)
+            # Rough token estimate: 1 token ≈ 4 characters
+            estimated_tokens = response_size / 4
+            return response_size, estimated_tokens
+        except httpx.ConnectError:
+            print(f"⚠️  Could not connect to {url} - is the server running?")
+            return 0, 0
+        except Exception as e:
+            print(f"❌ Error measuring {url}: {e}")
+            return 0, 0
+
+
+async def test_projects_endpoint():
+    """Test /api/projects with and without include_content."""
+    base_url = "http://localhost:8181/api/projects"
+    
+    print("\n=== Testing Projects Endpoint ===")
+    
+    # Test with full content (backward compatibility)
+    size_full, tokens_full = await measure_response_size(base_url, {"include_content": "true"})
+    if size_full > 0:
+        print(f"Full content: {size_full:,} bytes | ~{tokens_full:,.0f} tokens")
+    else:
+        print("⚠️  Skipping - server not available")
+        return
+    
+    # Test lightweight
+    size_light, tokens_light = await measure_response_size(base_url, {"include_content": "false"})
+    print(f"Lightweight: {size_light:,} bytes | ~{tokens_light:,.0f} tokens")
+    
+    # Calculate reduction
+    if size_full > 0:
+        reduction = (1 - size_light / size_full) * 100 if size_full > size_light else 0
+        print(f"Reduction: {reduction:.1f}%")
+        
+        if reduction > 50:
+            print("✅ Significant token reduction achieved!")
+        else:
+            print("⚠️  Token reduction less than expected")
+    
+    # Verify backward compatibility - default should include content
+    size_default, _ = await measure_response_size(base_url)
+    if size_default > 0:
+        if abs(size_default - size_full) < 100:  # Allow small variation
+            print("✅ Backward compatibility maintained (default includes content)")
+        else:
+            print("⚠️  Default behavior may have changed")
+
+
+async def test_tasks_endpoint():
+    """Test /api/tasks with exclude_large_fields."""
+    base_url = "http://localhost:8181/api/tasks"
+    
+    print("\n=== Testing Tasks Endpoint ===")
+    
+    # Test with full content
+    size_full, tokens_full = await measure_response_size(base_url, {"exclude_large_fields": "false"})
+    if size_full > 0:
+        print(f"Full content: {size_full:,} bytes | ~{tokens_full:,.0f} tokens")
+    else:
+        print("⚠️  Skipping - server not available")
+        return
+    
+    # Test lightweight
+    size_light, tokens_light = await measure_response_size(base_url, {"exclude_large_fields": "true"})
+    print(f"Lightweight: {size_light:,} bytes | ~{tokens_light:,.0f} tokens")
+    
+    # Calculate reduction
+    if size_full > size_light:
+        reduction = (1 - size_light / size_full) * 100
+        print(f"Reduction: {reduction:.1f}%")
+        
+        if reduction > 30:  # Tasks may have less reduction if fewer have large fields
+            print("✅ Token reduction achieved for tasks!")
+        else:
+            print("ℹ️  Minimal reduction (tasks may not have large fields)")
+
+
+async def test_documents_endpoint():
+    """Test /api/projects/{id}/docs with include_content."""
+    # First get a project ID if available
+    async with httpx.AsyncClient() as client:
+        try:
+            response = await client.get(
+                "http://localhost:8181/api/projects", 
+                params={"include_content": "false"},
+                timeout=10.0
+            )
+            if response.status_code == 200:
+                projects = response.json()
+                if projects and len(projects) > 0:
+                    project_id = projects[0]["id"]
+                    print(f"\n=== Testing Documents Endpoint (Project: {project_id[:8]}...) ===")
+                    
+                    base_url = f"http://localhost:8181/api/projects/{project_id}/docs"
+                    
+                    # Test with content
+                    size_full, tokens_full = await measure_response_size(base_url, {"include_content": "true"})
+                    print(f"With content: {size_full:,} bytes | ~{tokens_full:,.0f} tokens")
+                    
+                    # Test without content (default)
+                    size_light, tokens_light = await measure_response_size(base_url, {"include_content": "false"})
+                    print(f"Metadata only: {size_light:,} bytes | ~{tokens_light:,.0f} tokens")
+                    
+                    # Calculate reduction if there are documents
+                    if size_full > size_light and size_full > 500:  # Only if meaningful data
+                        reduction = (1 - size_light / size_full) * 100
+                        print(f"Reduction: {reduction:.1f}%")
+                        print("✅ Document endpoint optimized!")
+                    else:
+                        print("ℹ️  No documents or minimal content in project")
+                else:
+                    print("\n⚠️  No projects available for document testing")
+        except Exception as e:
+            print(f"\n⚠️  Could not test documents endpoint: {e}")
+
+
+async def test_mcp_endpoints():
+    """Test MCP endpoints if available."""
+    mcp_url = "http://localhost:8051/health"
+    
+    print("\n=== Testing MCP Server ===")
+    
+    async with httpx.AsyncClient() as client:
+        try:
+            response = await client.get(mcp_url, timeout=5.0)
+            if response.status_code == 200:
+                print("✅ MCP server is running")
+                # Could add specific MCP tool tests here
+            else:
+                print(f"⚠️  MCP server returned status {response.status_code}")
+        except httpx.ConnectError:
+            print("ℹ️  MCP server not running (optional for tests)")
+        except Exception as e:
+            print(f"⚠️  Could not check MCP server: {e}")
+
+
+async def main():
+    """Run all integration tests."""
+    print("=" * 60)
+    print("Token Optimization Integration Tests")
+    print("=" * 60)
+    
+    # Check if server is running
+    async with httpx.AsyncClient() as client:
+        try:
+            response = await client.get("http://localhost:8181/health", timeout=5.0)
+            if response.status_code == 200:
+                print("✅ Server is healthy and running")
+            else:
+                print(f"⚠️  Server returned status {response.status_code}")
+        except httpx.ConnectError:
+            print("❌ Server is not running! Start with: docker-compose up -d")
+            print("\nTests require a running server. Please start the services first.")
+            return
+        except Exception as e:
+            print(f"❌ Error checking server health: {e}")
+            return
+    
+    # Run tests
+    await test_projects_endpoint()
+    await test_tasks_endpoint()
+    await test_documents_endpoint()
+    await test_mcp_endpoints()
+    
+    print("\n" + "=" * 60)
+    print("✅ Integration tests completed!")
+    print("=" * 60)
+
+
+if __name__ == "__main__":
+    asyncio.run(main())
\ No newline at end of file