Add generate_badge and get_website_preview tools, refactor blob access (#52)

* Add generate_badge and get_website_preview tools, refactor blob access

- Re-add generate_badge (List[ContentBlock] with SVG + text)
- Re-add get_website_preview (List[ContentBlock] with TextContent + ResourceLink)
- Refactor get_snippet_with_metadata to use blob input binding instead of SDK
- Refactor save_snippet_structured to use blob output binding instead of SDK
- Add connection string fallback in batch_save_snippets for local dev
- Add aiohttp to requirements.txt
- Update README with new tools

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Remove trailing newlines

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: lilyjma

src/FunctionsMcpTool/README.md

@@ -15,7 +15,9 @@ This project is a Python Azure Function app that exposes multiple MCP (Model Con
 | `get_snippet` | Retrieves a code snippet from blob storage |
 | `save_snippet` | Saves a code snippet to blob storage |
 | `generate_qr_code` | Generates a QR code image from text |
-| `get_snippet_with_metadata` | Retrieves a snippet with structured metadata |
+| `generate_badge` | Generates an SVG status badge (List[ContentBlock]) |
+| `get_website_preview` | Fetches website metadata and returns a resource link (List[ContentBlock]) |
+| `get_snippet_with_metadata` | Retrieves a snippet with structured metadata (CallToolResult) |
 | `batch_save_snippets` | Saves multiple snippets at once |
 | `save_snippet_structured` | Saves a snippet and returns a structured dataclass |
 

src/FunctionsMcpTool/function_app.py

@@ -2,13 +2,14 @@
 import base64
 import json
 import os
+import re
 from dataclasses import dataclass
 from datetime import datetime, timezone
-from typing import Optional
+from typing import Optional, List
 from io import BytesIO
 
 import azure.functions as func
-from mcp.types import ImageContent, TextContent, CallToolResult
+from mcp.types import ImageContent, TextContent, ContentBlock, ResourceLink, CallToolResult
 from azure.storage.blob import BlobServiceClient
 
 app = func.FunctionApp(http_auth_level=func.AuthLevel.FUNCTION)
@@ -93,6 +94,87 @@ def generate_qr_code(text: str) -> ImageContent:
     )
 
 
+@app.mcp_tool()
+@app.mcp_tool_property(arg_name="label", description="The label text for the badge.", is_required=True)
+@app.mcp_tool_property(arg_name="value", description="The value text for the badge.", is_required=True)
+@app.mcp_tool_property(arg_name="color", description="The hex color for the value section (e.g., '#4CAF50').", is_required=False)
+def generate_badge(label: str, value: str, color: str = "#4CAF50") -> List[ContentBlock]:
+    """Demonstrates returning multiple content blocks (List[ContentBlock]). Generates an SVG status badge and returns it alongside a text description."""
+    logging.info(f"Generating badge: {label} | {value}")
+    
+    label_width = len(label) * 7 + 12
+    value_width = len(value) * 7 + 12
+    total_width = label_width + value_width
+    
+    svg = f"""<svg xmlns="http://www.w3.org/2000/svg" width="{total_width}" height="20">
+  <rect width="{label_width}" height="20" fill="#555"/>
+  <rect x="{label_width}" width="{value_width}" height="20" fill="{color}"/>
+  <text x="{label_width // 2}" y="14" fill="#fff" text-anchor="middle"
+        font-family="Verdana,sans-serif" font-size="11">{label}</text>
+  <text x="{label_width + value_width // 2}" y="14" fill="#fff" text-anchor="middle"
+        font-family="Verdana,sans-serif" font-size="11">{value}</text>
+</svg>"""
+    
+    return [
+        TextContent(type="text", text=f"Badge: {label} — {value}"),
+        ImageContent(
+            type="image",
+            data=base64.b64encode(svg.encode('utf-8')).decode('utf-8'),
+            mimeType="image/svg+xml"
+        )
+    ]
+
+
+@app.mcp_tool()
+@app.mcp_tool_property(arg_name="url", description="The URL of the website to preview.", is_required=True)
+async def get_website_preview(url: str) -> List[ContentBlock]:
+    """Demonstrates returning TextContentBlock and ResourceLinkBlock together. Fetches basic metadata from a URL and returns it with a resource link."""
+    import aiohttp
+    import html
+    
+    logging.info(f"Fetching website preview for {url}")
+    
+    # Ensure URL has a protocol
+    if not url.startswith(('http://', 'https://')):
+        url = f'https://{url}'
+        logging.info(f"Added https:// protocol to URL: {url}")
+    
+    title = url
+    description = "No description available."
+    
+    try:
+        async with aiohttp.ClientSession() as session:
+            async with session.get(url, timeout=aiohttp.ClientTimeout(total=10), 
+                                  headers={"User-Agent": "MCPTool/1.0"}) as response:
+                html_content = await response.text()
+                
+                # Extract title
+                title_match = re.search(r'<title[^>]*>(.*?)</title>', html_content, re.IGNORECASE)
+                if title_match:
+                    title = html.unescape(title_match.group(1)).strip()
+                
+                # Extract description
+                desc_match = re.search(
+                    r'<meta[^>]+name=["\']description["\'][^>]+content=["\']([^"\']*)["\'\']',
+                    html_content,
+                    re.IGNORECASE
+                )
+                if desc_match:
+                    description = html.unescape(desc_match.group(1)).strip()
+    
+    except Exception as ex:
+        logging.warning(f"Failed to fetch metadata for {url}: {ex}")
+        description = f"Could not fetch metadata: {str(ex)}"
+    
+    return [
+        TextContent(type="text", text=f"{title}\n\n{description}"),
+        ResourceLink(
+            type="resource_link",
+            uri=url,
+            name=title,
+            description=description
+        )
+    ]
 
 # ============================================================================
 # Snippet Data Class
@@ -121,47 +203,33 @@ class Snippet:
 
 @app.mcp_tool()
 @app.mcp_tool_property(arg_name="snippetname", description="The name of the snippet.", is_required=True)
-def get_snippet_with_metadata(snippetname: str) -> CallToolResult:
+@app.blob_input(arg_name="file", connection="AzureWebJobsStorage", path=_BLOB_PATH)
+def get_snippet_with_metadata(file: func.InputStream, snippetname: str) -> CallToolResult:
     """
     Demonstrates returning both content blocks and structured metadata via CallToolResult.
-    
+
     Returns a CallToolResult with:
     - content: List of ContentBlock objects (for backward compatibility)
     - structured_content: JSON metadata (for clients that support it)
-    
+
     This pattern allows clients to choose between simple text content or
     richer structured data depending on their capabilities.
     """
     logging.info(f"Getting snippet with metadata: {snippetname}")
-    
-    # Try to read the snippet from blob storage
+
     snippet_content = None
     try:
-        blob_service_uri = os.environ.get("AzureWebJobsStorage__blobServiceUri")
-        
-        if blob_service_uri:
-            from azure.identity import DefaultAzureCredential
-            credential = DefaultAzureCredential(
-                managed_identity_client_id=os.environ.get("AzureWebJobsStorage__clientId")
-            )
-            blob_service_client = BlobServiceClient(blob_service_uri, credential=credential)
-            container_client = blob_service_client.get_container_client("snippets")
-            blob_client = container_client.get_blob_client(f"{snippetname}.json")
-            
-            blob_data = blob_client.download_blob()
-            snippet_content = blob_data.readall().decode('utf-8')
+        snippet_content = file.read().decode("utf-8")
     except Exception as ex:
         logging.warning(f"Could not read snippet '{snippetname}': {ex}")
-    
-    # Build metadata
+
     metadata = {
         "name": snippetname,
         "found": snippet_content is not None,
         "character_count": len(snippet_content) if snippet_content else 0,
         "retrieved_at": datetime.now(timezone.utc).isoformat()
     }
-    
-    # Return CallToolResult with both content blocks and structured metadata
+
     return CallToolResult(
         content=[
             TextContent(
@@ -186,18 +254,21 @@ def get_snippet_with_metadata(snippetname: str) -> CallToolResult:
 def batch_save_snippets(snippet_items) -> str:
     """
     Demonstrates batch tool inputs - saving multiple snippets in one operation.
+
+    Accepts an array of snippet objects and saves each one to blob storage. 
     
-    Accepts an array of snippet objects and saves each one to blob storage.
     This pattern is useful for bulk operations and reduces the number of
     tool invocations needed.
     
+    Uses managed identity when deployed to Azure, falls back to connection
+    string for local development with Azurite.
+
     Args:
         snippet_items: List of dicts with 'name' and 'content' keys (or JSON string)
-        
+
     Returns:
         JSON string with summary of saved snippets
     """
-    # Parse snippet_items if it's a string
     if isinstance(snippet_items, str):
         try:
             snippet_items = json.loads(snippet_items)
@@ -206,58 +277,63 @@ def batch_save_snippets(snippet_items) -> str:
             return json.dumps({
                 "error": f"Invalid JSON format: {str(e)}"
             })
-    
+
     logging.info(f"Batch saving {len(snippet_items)} snippets")
-    
+
     try:
+        # Try managed identity first (Azure), fall back to connection string (local)
         blob_service_uri = os.environ.get("AzureWebJobsStorage__blobServiceUri")
-        if not blob_service_uri:
-            return json.dumps({
-                "error": "AzureWebJobsStorage__blobServiceUri not configured"
-            })
-        
-        from azure.identity import DefaultAzureCredential
-        credential = DefaultAzureCredential(
-            managed_identity_client_id=os.environ.get("AzureWebJobsStorage__clientId")
-        )
-        blob_service_client = BlobServiceClient(blob_service_uri, credential=credential)
+        if blob_service_uri:
+            from azure.identity import DefaultAzureCredential
+            credential = DefaultAzureCredential(
+                managed_identity_client_id=os.environ.get("AzureWebJobsStorage__clientId")
+            )
+            blob_service_client = BlobServiceClient(blob_service_uri, credential=credential)
+        else:
+            connection_string = os.environ.get("AzureWebJobsStorage")
+            if not connection_string:
+                return json.dumps({
+                    "error": "No blob storage configuration found"
+                })
+            blob_service_client = BlobServiceClient.from_connection_string(connection_string)
+
         container_client = blob_service_client.get_container_client("snippets")
-        
+
         # Create container if it doesn't exist
         try:
             container_client.create_container()
         except:
             pass  # Container already exists
-        
+
         saved_snippets = []
-        
+
         for item in snippet_items:
             try:
                 name = item.get("name")
                 content = item.get("content", "")
-                
+
                 if not name:
                     logging.warning("Skipping snippet with no name")
                     continue
-                
+
                 blob_client = container_client.get_blob_client(f"{name}.json")
                 blob_client.upload_blob(
                     content,
                     overwrite=True
                 )
                 saved_snippets.append(name)
                 logging.info(f"Saved snippet: {name}")
-                
+
             except Exception as ex:
                 logging.error(f"Failed to save snippet {item.get('name', 'unknown')}: {ex}")
-        
+
         result = {
             "message": f"Successfully saved {len(saved_snippets)} snippets",
             "snippets": saved_snippets
         }
-        
+
         return json.dumps(result, indent=2)
-        
+
     except Exception as ex:
         logging.error(f"Batch save failed: {ex}")
         return json.dumps({
@@ -268,7 +344,8 @@ def batch_save_snippets(snippet_items) -> str:
 @app.mcp_tool()
 @app.mcp_tool_property(arg_name="name", description="The name of the snippet", is_required=True)
 @app.mcp_tool_property(arg_name="content", description="The code snippet content", is_required=True)
-def save_snippet_structured(name: str, content: str) -> Snippet:
+@app.blob_output(arg_name="file", connection="AzureWebJobsStorage", path="snippets/{mcptoolargs.name}.json")
+def save_snippet_structured(file: func.Out[str], name: str, content: str) -> Snippet:
     """
     Demonstrates returning a structured data class (Snippet POCO equivalent).
     
@@ -284,24 +361,5 @@ def save_snippet_structured(name: str, content: str) -> Snippet:
         Snippet dataclass instance
     """
     logging.info(f"Saving snippet '{name}' as structured content")
-    
-    # Save to blob storage
-    try:
-        blob_service_uri = os.environ.get("AzureWebJobsStorage__blobServiceUri")
-        if not blob_service_uri:
-            logging.warning("AzureWebJobsStorage__blobServiceUri not configured")
-            return Snippet(name=name, content=content)
-        
-        from azure.identity import DefaultAzureCredential
-        credential = DefaultAzureCredential(
-            managed_identity_client_id=os.environ.get("AzureWebJobsStorage__clientId")
-        )
-        blob_service_client = BlobServiceClient(blob_service_uri, credential=credential)
-        container_client = blob_service_client.get_container_client("snippets")
-        blob_client = container_client.get_blob_client(f"{name}.json")
-        blob_client.upload_blob(content, overwrite=True)
-    except Exception as ex:
-        logging.warning(f"Could not save to blob storage: {ex}")
-    
-    # Return structured Snippet object
+    file.set(content)
     return Snippet(name=name, content=content)

src/FunctionsMcpTool/requirements.txt

@@ -6,4 +6,5 @@ azure-functions>=2.2.0b3
 qrcode[pil]
 azure-storage-blob
 azure-identity
+aiohttp
 mcp