Obsidian MCP Server

Instructions

Implementation Reference

• src/obsidian_mcp/server.py:569-610 (handler)

  MCP tool handler for 'create_note'. Registers the tool and implements the logic by calling the vault's create_note method, including input validation and frontmatter handling for tags.
  @mcp.tool(name="create_note", description="Create a new note in the vault") def create_note( path: str, content: str, tags: list[str] | None = None, overwrite: bool = False ) -> str: """ Create a new note. Args: path: Relative path for the new note (e.g., "Projects/New Idea.md") content: Content of the note tags: Optional list of tags to add to frontmatter overwrite: If true, overwrite existing note Returns: Success message """ if not path or not path.strip(): return "Error: Path cannot be empty" if len(path) > 1000: return "Error: Path too long" if len(content) > 1_000_000: return "Error: Content too large (max 1MB)" context = _get_context() try: # Build frontmatter if tags provided frontmatter = None if tags: frontmatter = {"tags": tags} context.vault.create_note(path, content, frontmatter, overwrite) return f"✓ Created note: {path}" except FileExistsError: return f"Error: Note already exists: {path} (use overwrite=true to replace)" except VaultSecurityError as e: return f"Error: Security violation: {e}" except Exception as e: logger.exception(f"Error creating note {path}") return f"Error creating note: {e}"
• src/obsidian_mcp/vault.py:470-511 (helper)

  Core implementation in ObsidianVault class that creates the note file, handles frontmatter insertion, directory creation, and security validation.
  def create_note( self, relative_path: str, content: str, frontmatter: dict[str, Any] | None = None, overwrite: bool = False, ) -> None: """ Create a new note in the vault. Args: relative_path: Path where to create the note content: Content of the note frontmatter: Optional frontmatter dict overwrite: If True, overwrite existing file Raises: VaultSecurityError: If path is invalid FileExistsError: If note already exists and overwrite=False """ file_path = self._validate_path(relative_path) # Check if already exists if file_path.exists() and not overwrite: raise FileExistsError(f"Note already exists: {relative_path}") # Ensure parent directory exists file_path.parent.mkdir(parents=True, exist_ok=True) # Build full content with frontmatter full_content = "" if frontmatter: full_content = "---\n" full_content += yaml.dump(frontmatter, default_flow_style=False, sort_keys=False) full_content += "---\n" full_content += content # Write file file_path.write_text(full_content, encoding="utf-8") logger.info(f"Created note: {relative_path}")
• src/obsidian_mcp/server.py:569-610 (registration)

  The @mcp.tool decorator registers the 'create_note' tool with FastMCP, defining its name, description, and input schema from function signature.
  @mcp.tool(name="create_note", description="Create a new note in the vault") def create_note( path: str, content: str, tags: list[str] | None = None, overwrite: bool = False ) -> str: """ Create a new note. Args: path: Relative path for the new note (e.g., "Projects/New Idea.md") content: Content of the note tags: Optional list of tags to add to frontmatter overwrite: If true, overwrite existing note Returns: Success message """ if not path or not path.strip(): return "Error: Path cannot be empty" if len(path) > 1000: return "Error: Path too long" if len(content) > 1_000_000: return "Error: Content too large (max 1MB)" context = _get_context() try: # Build frontmatter if tags provided frontmatter = None if tags: frontmatter = {"tags": tags} context.vault.create_note(path, content, frontmatter, overwrite) return f"✓ Created note: {path}" except FileExistsError: return f"Error: Note already exists: {path} (use overwrite=true to replace)" except VaultSecurityError as e: return f"Error: Security violation: {e}" except Exception as e: logger.exception(f"Error creating note {path}") return f"Error creating note: {e}"