added new backlink tool

documentation/MCP.md

@@ -14,6 +14,7 @@ MCP (Model Context Protocol) is an open standard that allows AI assistants to se
 - 📂 **Organize** notes (move, rename, folders)
 - 📋 **Use templates** to create structured notes
 - 🔗 **Explore** the knowledge graph
+- 🔙 **Discover backlinks** (notes that link to a specific note)
 
 ## Quick Setup
 
@@ -126,6 +127,7 @@ The MCP server provides these tools to AI assistants:
 | `list_tags` | List all tags with note counts |
 | `get_notes_by_tag` | Find notes with a specific tag (supports pagination) |
 | `get_graph` | Get knowledge graph data |
+| `get_backlinks` | Get notes that link to a specific note (reverse links) |
 
 ### Note Management
 
@@ -172,6 +174,23 @@ Some tools support optional pagination parameters for large vaults:
 
 ---
 
+### `get_backlinks`
+
+Find all notes that link TO a specific note (reverse links / backlinks). Useful for understanding how a note connects to your knowledge base.
+
+| Parameter | Type | Required | Description |
+|-----------|------|----------|-------------|
+| `path` | string | Yes | Path to the note to find backlinks for |
+
+**Returns:** List of notes that contain links to the specified note, with context snippets showing where the link appears.
+
+**Example prompts:**
+- "What notes link to my Project Alpha note?"
+- "Show me the backlinks for meeting-notes.md"
+- "Find all notes that reference my API documentation"
+
+---
+
 ### `append_to_note`
 
 Append content to an existing note without overwriting. Perfect for journals, logs, or collecting ideas.
@@ -266,6 +285,12 @@ Once configured, you can interact with your notes naturally:
 > 
 > "Created 'meetings/design-review-2024-03-13.md' from your meeting-notes template."
 
+> **User:** "What notes link to my Project Alpha document?"
+> 
+> **AI:** *Uses `get_backlinks` to find reverse links*
+> 
+> "3 notes reference Project Alpha: your meeting notes from March 12, the quarterly review, and the team standup notes..."
+
 ## Authentication
 
 If you have authentication enabled in NoteDiscovery:

mcp_server/client.py

@@ -354,11 +354,24 @@ class NoteDiscoveryClient:
     def get_graph(self) -> APIResponse:
         """
         Get note relationship graph data.
-        
+
         Returns:
             APIResponse with graph nodes and links
         """
         return self._request("GET", "/api/graph")
+
+    def get_backlinks(self, path: str) -> APIResponse:
+        """
+        Get backlinks (reverse links) for a specific note.
+
+        Args:
+            path: Note path (e.g., "folder/note.md")
+
+        Returns:
+            APIResponse with note info and backlinks
+        """
+        encoded_path = urllib.parse.quote(path, safe="")
+        return self._request("GET", f"/api/notes/{encoded_path}", params={"include_backlinks": "true"})
     
     # =========================================================================
     # Templates API

mcp_server/server.py

@@ -414,6 +414,41 @@ class MCPServer:
                 output.append(f"  {note}: {count} connections")
         
         return "\n".join(output)
+
+    def _tool_get_backlinks(self, args: dict) -> str:
+        """Get backlinks (reverse links) for a note."""
+        path = args.get("path", "")
+        is_valid, error = self._validate_path(path)
+        if not is_valid:
+            return f"Error: {error}"
+
+        response = self.client.get_backlinks(path)
+
+        if not response.success:
+            return f"Failed to get backlinks: {response.error}"
+
+        data = response.data or {}
+        backlinks = data.get("backlinks", [])
+        note_path = data.get("path", path)
+
+        if not backlinks:
+            return f"No backlinks found for '{note_path}'. No other notes link to this note."
+
+        output = [f"Backlinks for '{note_path}': {len(backlinks)} note(s) link to this note\n"]
+
+        for bl in backlinks:
+            bl_path = bl.get("path", "unknown")
+            bl_name = bl.get("name", bl_path)
+            references = bl.get("references", [])
+
+            output.append(f"📄 {bl_name} ({bl_path})")
+            for ref in references:
+                line_num = ref.get("line_number", "?")
+                context = ref.get("context", "")
+                link_type = ref.get("type", "link")
+                output.append(f"   Line {line_num} [{link_type}]: {context}")
+
+        return "\n".join(output)
     
     def _tool_create_note(self, args: dict) -> str:
         """Create or update a note."""

mcp_server/tools.py

@@ -114,6 +114,20 @@ TOOLS: list[dict[str, Any]] = [
             "required": []
         }
     },
+    {
+        "name": "get_backlinks",
+        "description": "Get all notes that link TO a specific note (backlinks/reverse links). Use this to discover what other notes reference the current note, helping understand its importance and connections in the knowledge base.",
+        "inputSchema": {
+            "type": "object",
+            "properties": {
+                "path": {
+                    "type": "string",
+                    "description": "Path to the note to find backlinks for (e.g., 'folder/note.md' or 'note.md')"
+                }
+            },
+            "required": ["path"]
+        }
+    },
     
     # =========================================================================
     # Note Management (Write Operations)