Update YAML Metadata
update_metadataModify YAML frontmatter in Markdown documents to update document metadata like status, tags, author, or date.
Instructions
Modifies the document's Frontmatter.
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| file_path | Yes | ||
| metadata | Yes |
Output Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| success | No |
Implementation Reference
- Main tool handler: acquires file lock, updates document metadata via Document.update_metadata(), performs atomic file write, updates cache, confirms journal entry. Handles write errors with rollback.
async def update_metadata( self, file_path: str, metadata: Dict[str, Any] ) -> Dict[str, Any]: abs_path = resolve_path(file_path) with FileLock(abs_path): doc = self.get_doc(file_path) result = doc.update_metadata(metadata) if "success" in result: try: self._atomic_write(file_path, doc.get_content()) self._update_cache_mtime(abs_path) doc.confirm_journal() except Exception as e: doc.rollback_last_entry() self.invalidate_cache(file_path) return {"error": f"Failed to write file: {e}"} return result - src/markdown_editor/server.py:330-356 (registration)Tool registration in @app.list_tools(): defines name, description, input/output schemas for update_metadata tool.
Tool( name="update_metadata", title="Update YAML Metadata", description="Modifies the document's Frontmatter.", inputSchema={ "type": "object", "properties": { "file_path": { "type": "string", "examples": ["./document.md", "./blog/post.md"], }, "metadata": { "type": "object", "examples": [ {"status": "published", "tags": ["mcp", "ai"]}, {"author": "John Doe", "date": "2025-12-27"}, ], }, }, "required": ["file_path", "metadata"], "additionalProperties": False, }, outputSchema={ "type": "object", "properties": {"success": {"type": "boolean"}}, }, ), - Input/output schema definition for the update_metadata tool, specifying file_path and metadata object.
Tool( name="update_metadata", title="Update YAML Metadata", description="Modifies the document's Frontmatter.", inputSchema={ "type": "object", "properties": { "file_path": { "type": "string", "examples": ["./document.md", "./blog/post.md"], }, "metadata": { "type": "object", "examples": [ {"status": "published", "tags": ["mcp", "ai"]}, {"author": "John Doe", "date": "2025-12-27"}, ], }, }, "required": ["file_path", "metadata"], "additionalProperties": False, }, outputSchema={ "type": "object", "properties": {"success": {"type": "boolean"}}, }, ), - Core Document class method: updates metadata dictionary, rebuilds raw content from structure, creates journal entry for undo support.
def update_metadata(self, new_metadata: Dict[str, Any]) -> Dict[str, Any]: """Update YAML metadata""" old = deepcopy(self.metadata) self.metadata.update(new_metadata) self._rebuild_raw_content() # Create journal entry for undo support entry = JournalEntry( operation="update_metadata", path="metadata", old_value=json.dumps(old, ensure_ascii=False), new_value=json.dumps(self.metadata, ensure_ascii=False), transaction_id=self._transaction_id, ) if not self._transaction_active: self.journal.append(entry) # Note: _save_journal() is NOT called here # Caller must call confirm_journal() after successful file write self.version += 1 return {"success": True, "old": old, "new": self.metadata} - src/markdown_editor/server.py:637-643 (registration)Dispatch logic in @app.call_tool(): calls the update_document_metadata handler when tool name matches.
elif name == "update_metadata": res = await update_document_metadata(file_path, arguments["metadata"]) return CallToolResult( content=[TextContent(type="text", text="Metadata updated")], structuredContent=res, isError="error" in res, )