diff --git a/README.md b/README.md
index e69de29b..fefe0106 100644
--- a/README.md
+++ b/README.md
@@ -0,0 +1,124 @@
+# Haiku SQLite RAG
+
+A SQLite-based Retrieval-Augmented Generation (RAG) system built for efficient document storage, chunking, and hybrid search capabilities.
+
+## Features
+
+- **Document Management**: Store and manage documents with automatic content parsing
+- **Smart Updates**: Intelligent file/URL monitoring with MD5-based change detection
+- **Hybrid Search**: Full-text search (FTS5) combined with vector embeddings
+- **Multi-format Support**: Parse 40+ file formats including PDF, DOCX, HTML, Markdown, and more
+- **Web Content**: Direct URL ingestion with automatic content type detection
+- **Vector Embeddings**: Uses sqlite-vec for efficient similarity search
+- **Automatic Chunking**: Intelligent document segmentation for better retrieval
+
+## Installation
+
+```bash
+uv pip install haiku.rag
+```
+
+or for development, checkout the repository and then,
+
+```bash
+# Install dependencies
+uv sync
+
+# Activate virtual environment
+source .venv/bin/activate
+```
+
+## Quick Start
+
+```python
+from pathlib import Path
+from haiku.rag.client import HaikuRAG
+
+# Initialize client with database path
+client = HaikuRAG("path/to/database.db")
+# Or use in-memory database for testing
+client = HaikuRAG(":memory:")
+
+# Create document from text
+doc = await client.create_document(
+    content="Your document content here",
+    uri="doc://example",
+    metadata={"source": "manual", "topic": "example"}
+)
+
+# Create document from file (auto-parses content)
+doc = await client.create_document_from_source("path/to/document.pdf")
+
+# Create document from URL
+doc = await client.create_document_from_source("https://example.com/article.html")
+
+# Retrieve documents
+doc = await client.get_document_by_id(1)
+doc = await client.get_document_by_uri("file:///path/to/document.pdf")
+
+# List all documents with pagination
+docs = await client.list_documents(limit=10, offset=0)
+
+# Update document content
+doc.content = "Updated content"
+await client.update_document(doc)
+
+# Delete document
+await client.delete_document(doc.id)
+
+# Clean up
+client.close()
+```
+
+## Smart Document Updates
+
+The system automatically tracks file changes using MD5 hashes:
+
+```python
+# First call - creates new document
+doc1 = await client.create_document_from_source("document.txt")
+
+# Second call - no changes, returns existing document (no processing)
+doc2 = await client.create_document_from_source("document.txt")
+assert doc1.id == doc2.id
+
+# After file modification - automatically updates existing document
+# File content changed...
+doc3 = await client.create_document_from_source("document.txt")
+assert doc1.id == doc3.id  # Same document
+assert doc3.content != doc1.content  # Updated content
+```
+
+## Supported File Formats
+
+The system supports 40+ file formats through MarkItDown:
+
+- **Documents**: PDF, DOCX, PPTX, XLSX
+- **Web**: HTML, XML
+- **Text**: TXT, MD, CSV, JSON, YAML
+- **Code**: PY, JS, TS, C, CPP, JAVA, GO, RS, and more
+- **Media**: MP3, WAV (transcription)
+
+## Document Metadata
+
+Documents automatically include metadata:
+
+```python
+doc = await client.create_document_from_source("example.pdf")
+print(doc.metadata)
+# {
+#   "contentType": "application/pdf",
+#   "md5": "abc123...",
+#   "custom_field": "value"  # Your custom metadata
+# }
+```
+
+## Contributing
+
+1. Fork the repository
+2. Create a feature branch
+3. Add tests for new functionality
+4. Ensure all tests pass: `pytest`
+5. Run type checking: `pyright`
+6. Run linting: `ruff check`
+7. Submit a pull request
diff --git a/src/haiku/rag/client.py b/src/haiku/rag/client.py
index 0e46b39b..1a7e8724 100644
--- a/src/haiku/rag/client.py
+++ b/src/haiku/rag/client.py
@@ -1,3 +1,5 @@
+import hashlib
+import mimetypes
 import tempfile
 from pathlib import Path
 from typing import Literal
@@ -11,7 +13,7 @@ from haiku.rag.store.models.document import Document
 from haiku.rag.store.repositories.document import DocumentRepository
 
 
-class RAGClient:
+class HaikuRAG:
     """High-level haiku-rag client."""
 
     def __init__(self, db_path: Path | Literal[":memory:"]):
@@ -31,16 +33,21 @@ class RAGClient:
         return await self.document_repository.create(document)
 
     async def create_document_from_source(
-        self, source: str | Path, metadata: dict | None = None
+        self, source: str | Path, metadata: dict = {}
     ) -> Document:
-        """Create a document from a file path or URL.
+        """Create or update a document from a file path or URL.
+
+        Checks if a document with the same URI already exists:
+        - If MD5 is unchanged, returns existing document
+        - If MD5 changed, updates the document
+        - If no document exists, creates a new one
 
         Args:
             source: File path (as string or Path) or URL to parse
             metadata: Optional metadata dictionary
 
         Returns:
-            Created Document instance
+            Document instance (created, updated, or existing)
 
         Raises:
             ValueError: If the file/URL cannot be parsed or doesn't exist
@@ -51,7 +58,7 @@ class RAGClient:
         source_str = str(source)
         parsed_url = urlparse(source_str)
         if parsed_url.scheme in ("http", "https"):
-            return await self._create_document_from_url(source_str, metadata)
+            return await self._create_or_update_document_from_url(source_str, metadata)
 
         # Handle as file path
         source_path = Path(source) if isinstance(source, str) else source
@@ -61,24 +68,52 @@ class RAGClient:
         if not source_path.exists():
             raise ValueError(f"File does not exist: {source_path}")
 
+        uri = str(source_path.resolve())
+        md5_hash = hashlib.md5(source_path.read_bytes()).hexdigest()
+
+        # Check if document already exists
+        existing_doc = await self.get_document_by_uri(uri)
+        if existing_doc and existing_doc.metadata.get("md5") == md5_hash:
+            # MD5 unchanged, return existing document
+            return existing_doc
+
         content = FileReader.parse_file(source_path)
 
-        # Create the document
-        return await self.create_document(
-            content=content, uri=str(source_path.resolve()), metadata=metadata
-        )
+        # Get content type from file extension
+        content_type, _ = mimetypes.guess_type(str(source_path))
+        if not content_type:
+            content_type = "application/octet-stream"
 
-    async def _create_document_from_url(
-        self, url: str, metadata: dict | None = None
+        # Merge metadata with contentType and md5
+        metadata.update({"contentType": content_type, "md5": md5_hash})
+
+        if existing_doc:
+            # Update existing document
+            existing_doc.content = content
+            existing_doc.metadata = metadata
+            return await self.update_document(existing_doc)
+        else:
+            # Create new document
+            return await self.create_document(
+                content=content, uri=uri, metadata=metadata
+            )
+
+    async def _create_or_update_document_from_url(
+        self, url: str, metadata: dict = {}
     ) -> Document:
-        """Create a document from a URL by downloading and parsing the content.
+        """Create or update a document from a URL by downloading and parsing the content.
+
+        Checks if a document with the same URI already exists:
+        - If MD5 is unchanged, returns existing document
+        - If MD5 changed, updates the document
+        - If no document exists, creates a new one
 
         Args:
             url: URL to download and parse
             metadata: Optional metadata dictionary
 
         Returns:
-            Created Document instance
+            Document instance (created, updated, or existing)
 
         Raises:
             ValueError: If the content cannot be parsed
@@ -88,10 +123,16 @@ class RAGClient:
             response = await client.get(url)
             response.raise_for_status()
 
+            md5_hash = hashlib.md5(response.content).hexdigest()
+
+            # Check if document already exists
+            existing_doc = await self.get_document_by_uri(url)
+            if existing_doc and existing_doc.metadata.get("md5") == md5_hash:
+                # MD5 unchanged, return existing document
+                return existing_doc
+
             # Get content type to determine file extension
             content_type = response.headers.get("content-type", "").lower()
-
-            # Try to determine file extension from content type or URL
             file_extension = self._get_extension_from_content_type_or_url(
                 url, content_type
             )
@@ -112,10 +153,17 @@ class RAGClient:
                 # Parse the content using FileReader
                 content = FileReader.parse_file(temp_path)
 
-                # Create the document with the original URL as URI
-                return await self.create_document(
-                    content=content, uri=url, metadata=metadata
-                )
+                # Merge metadata with contentType and md5
+                metadata.update({"contentType": content_type, "md5": md5_hash})
+
+                if existing_doc:
+                    existing_doc.content = content
+                    existing_doc.metadata = metadata
+                    return await self.update_document(existing_doc)
+                else:
+                    return await self.create_document(
+                        content=content, uri=url, metadata=metadata
+                    )
             finally:
                 # Clean up temporary file
                 temp_path.unlink(missing_ok=True)
diff --git a/tests/test_client.py b/tests/test_client.py
index d5af9df3..31b34ee0 100644
--- a/tests/test_client.py
+++ b/tests/test_client.py
@@ -6,14 +6,14 @@ import httpx
 import pytest
 from datasets import Dataset
 
-from haiku.rag.client import RAGClient
+from haiku.rag.client import HaikuRAG
 
 
 @pytest.mark.asyncio
 async def test_client_document_crud(qa_corpus: Dataset):
-    """Test RAGClient CRUD operations for documents."""
+    """Test HaikuRAG CRUD operations for documents."""
     # Create client with in-memory database
-    client = RAGClient(":memory:")
+    client = HaikuRAG(":memory:")
 
     # Get test data
     first_doc = qa_corpus[0]
@@ -82,7 +82,7 @@ async def test_client_document_crud(qa_corpus: Dataset):
 @pytest.mark.asyncio
 async def test_client_create_document_from_source():
     """Test creating a document from a file source."""
-    client = RAGClient(":memory:")
+    client = HaikuRAG(":memory:")
 
     # Create a temporary text file
     with tempfile.NamedTemporaryFile(mode="w", suffix=".txt", delete=False) as f:
@@ -100,6 +100,9 @@ async def test_client_create_document_from_source():
         assert doc.content == test_content
         assert doc.uri == str(temp_path.resolve())
         assert doc.metadata["source_type"] == "file"
+        assert "contentType" in doc.metadata
+        assert "md5" in doc.metadata
+        assert doc.metadata["contentType"] == "text/plain"
 
         # Test create_document_from_source with string path
         doc2 = await client.create_document_from_source(source=str(temp_path))
@@ -107,6 +110,8 @@ async def test_client_create_document_from_source():
         assert doc2.id is not None
         assert doc2.content == test_content
         assert doc2.uri == str(temp_path.resolve())
+        assert "contentType" in doc2.metadata
+        assert "md5" in doc2.metadata
 
     finally:
         # Clean up
@@ -117,7 +122,7 @@ async def test_client_create_document_from_source():
 @pytest.mark.asyncio
 async def test_client_create_document_from_source_unsupported():
     """Test creating a document from an unsupported file type."""
-    client = RAGClient(":memory:")
+    client = HaikuRAG(":memory:")
 
     # Create a temporary file with unsupported extension
     with tempfile.NamedTemporaryFile(
@@ -139,7 +144,7 @@ async def test_client_create_document_from_source_unsupported():
 @pytest.mark.asyncio
 async def test_client_create_document_from_source_nonexistent():
     """Test creating a document from a non-existent file."""
-    client = RAGClient(":memory:")
+    client = HaikuRAG(":memory:")
 
     non_existent_path = Path("/non/existent/file.txt")
 
@@ -153,7 +158,7 @@ async def test_client_create_document_from_source_nonexistent():
 @pytest.mark.asyncio
 async def test_client_create_document_from_url():
     """Test creating a document from a URL."""
-    client = RAGClient(":memory:")
+    client = HaikuRAG(":memory:")
 
     # Mock the HTTP response
     mock_response = AsyncMock()
@@ -171,6 +176,9 @@ async def test_client_create_document_from_url():
         assert "test content" in doc.content
         assert doc.uri == "https://example.com/test.html"
         assert doc.metadata["source_type"] == "web"
+        assert "contentType" in doc.metadata
+        assert "md5" in doc.metadata
+        assert doc.metadata["contentType"] == "text/html"
 
     client.close()
 
@@ -178,7 +186,7 @@ async def test_client_create_document_from_url():
 @pytest.mark.asyncio
 async def test_client_create_document_from_url_with_different_content_types():
     """Test creating documents from URLs with different content types."""
-    client = RAGClient(":memory:")
+    client = HaikuRAG(":memory:")
 
     # Test JSON content
     mock_json_response = AsyncMock()
@@ -196,6 +204,9 @@ async def test_client_create_document_from_url_with_different_content_types():
         assert doc.id is not None
         assert "Test JSON" in doc.content
         assert doc.uri == "https://api.example.com/data.json"
+        assert "contentType" in doc.metadata
+        assert "md5" in doc.metadata
+        assert doc.metadata["contentType"] == "application/json"
 
     # Test plain text content
     mock_text_response = AsyncMock()
@@ -209,6 +220,9 @@ async def test_client_create_document_from_url_with_different_content_types():
         assert doc.id is not None
         assert doc.content == "This is plain text content from a URL."
         assert doc.uri == "https://example.com/readme.txt"
+        assert "contentType" in doc.metadata
+        assert "md5" in doc.metadata
+        assert doc.metadata["contentType"] == "text/plain"
 
     client.close()
 
@@ -216,7 +230,7 @@ async def test_client_create_document_from_url_with_different_content_types():
 @pytest.mark.asyncio
 async def test_client_create_document_from_url_unsupported_content():
     """Test creating a document from URL with unsupported content type."""
-    client = RAGClient(":memory:")
+    client = HaikuRAG(":memory:")
 
     # Mock response with unsupported content type
     mock_response = AsyncMock()
@@ -234,7 +248,7 @@ async def test_client_create_document_from_url_unsupported_content():
 @pytest.mark.asyncio
 async def test_client_create_document_from_url_http_error():
     """Test handling HTTP errors when creating document from URL."""
-    client = RAGClient(":memory:")
+    client = HaikuRAG(":memory:")
 
     with patch("httpx.AsyncClient.get") as mock_get:
         mock_get.side_effect = httpx.HTTPStatusError(
@@ -254,7 +268,7 @@ async def test_client_create_document_from_url_http_error():
 @pytest.mark.asyncio
 async def test_get_extension_from_content_type_or_url():
     """Test the helper method for determining file extensions."""
-    client = RAGClient(":memory:")
+    client = HaikuRAG(":memory:")
 
     # Test content type mappings
     assert client._get_extension_from_content_type_or_url("", "text/html") == ".html"
@@ -292,3 +306,123 @@ async def test_get_extension_from_content_type_or_url():
     )
 
     client.close()
+
+
+@pytest.mark.asyncio
+async def test_client_metadata_content_type_and_md5():
+    """Test that contentType and md5 metadata are correctly set."""
+    import hashlib
+
+    client = HaikuRAG(":memory:")
+
+    # Create a temporary file with known content
+    test_content = "Test content for MD5 calculation."
+    expected_md5 = hashlib.md5(test_content.encode()).hexdigest()
+
+    with tempfile.NamedTemporaryFile(mode="w", suffix=".txt", delete=False) as f:
+        f.write(test_content)
+        temp_path = Path(f.name)
+
+    try:
+        doc = await client.create_document_from_source(temp_path)
+
+        assert doc.metadata["contentType"] == "text/plain"
+        assert doc.metadata["md5"] == expected_md5
+
+        mock_response = AsyncMock()
+        mock_response.content = test_content.encode()
+        mock_response.headers = {"content-type": "text/plain"}
+        mock_response.raise_for_status = AsyncMock()
+
+        with patch("httpx.AsyncClient.get", return_value=mock_response):
+            url_doc = await client.create_document_from_source(
+                "https://example.com/test.txt"
+            )
+
+            assert url_doc.metadata["contentType"] == "text/plain"
+            assert url_doc.metadata["md5"] == expected_md5
+
+    finally:
+        temp_path.unlink()
+        client.close()
+
+
+@pytest.mark.asyncio
+async def test_client_create_update_no_op_behavior():
+    """Test create/update/no-op behavior based on MD5 changes."""
+    client = HaikuRAG(":memory:")
+
+    # Create a temporary file
+    test_content = "Original content for testing."
+    with tempfile.NamedTemporaryFile(mode="w", suffix=".txt", delete=False) as f:
+        f.write(test_content)
+        temp_path = Path(f.name)
+
+    try:
+        # First call - should create new document
+        doc1 = await client.create_document_from_source(temp_path)
+        assert doc1.id is not None
+        assert doc1.content == test_content
+        original_id = doc1.id
+
+        # Second call with same content - should return existing document (no-op)
+        doc2 = await client.create_document_from_source(temp_path)
+        assert doc2.id == original_id  # Same document
+        assert doc2.content == test_content
+
+        # Modify file content
+        updated_content = "Updated content for testing."
+        temp_path.write_text(updated_content)
+
+        # Third call with changed content - should update existing document
+        doc3 = await client.create_document_from_source(temp_path)
+        assert doc3.id == original_id  # Same document ID
+        assert doc3.content == updated_content  # Updated content
+
+        # Verify the document was actually updated in database
+        retrieved_doc = await client.get_document_by_id(original_id)
+        assert retrieved_doc is not None
+        assert retrieved_doc.content == updated_content
+
+    finally:
+        temp_path.unlink()
+        client.close()
+
+
+@pytest.mark.asyncio
+async def test_client_url_create_update_no_op_behavior():
+    """Test create/update/no-op behavior for URLs based on MD5 changes."""
+    client = HaikuRAG(":memory:")
+
+    url = "https://example.com/test.txt"
+    original_content = b"Original URL content"
+    updated_content = b"Updated URL content"
+
+    # Mock first response
+    mock_response1 = AsyncMock()
+    mock_response1.content = original_content
+    mock_response1.headers = {"content-type": "text/plain"}
+    mock_response1.raise_for_status = AsyncMock()
+
+    with patch("httpx.AsyncClient.get", return_value=mock_response1):
+        # First call - should create new document
+        doc1 = await client.create_document_from_source(url)
+        assert doc1.id is not None
+        original_id = doc1.id
+
+        # Second call with same content - should return existing document (no-op)
+        doc2 = await client.create_document_from_source(url)
+        assert doc2.id == original_id  # Same document
+
+    mock_response2 = AsyncMock()
+    mock_response2.content = updated_content
+    mock_response2.headers = {"content-type": "text/plain"}
+    mock_response2.raise_for_status = AsyncMock()
+
+    with patch("httpx.AsyncClient.get", return_value=mock_response2):
+        # Third call with changed content - should update existing document
+        doc3 = await client.create_document_from_source(url)
+        assert doc3.id == original_id  # Same document ID
+        assert doc3.content == updated_content.decode()  # Updated content
+
+    client.close()