Aseprite MCP Tools

Instructions

Implementation Reference

• aseprite_mcp/tools/export.py:12-74 (handler)

  The 'export_sprite' tool handler function that executes Aseprite export via command line arguments.

  @mcp.tool()
  async def export_sprite(
      filename: str, 
      output_filename: str, 
      format: Optional[str] = None,
      scale: float = 1.0,
      frame_range: Optional[str] = None
  ) -> str:
      """Export the Aseprite file to another format.
  
      Args:
          filename: Name of the Aseprite file to export
          output_filename: Name of the output file
          format: Output format (default: inferred from extension, can be "png", "gif", "jpg", etc.)
          scale: Export scale factor (default: 1.0)
          frame_range: Frame range to export (e.g., "1-5" or "2,4,6")
      """
      try:
          # Validate inputs
          file_path = validate_file_path(filename, must_exist=True)
          output_path = validate_file_path(output_filename, must_exist=False)
          
          # Determine format from extension if not provided
          if format is None:
              format = output_path.suffix.lstrip('.')
              if not format:
                  format = 'png'
          
          format = validate_export_format(format)
          
          # Ensure output filename has the correct extension
          if not output_path.suffix.lower() == f".{format}":
              output_path = output_path.with_suffix(f".{format}")
          
          # Validate scale
          if scale <= 0:
              raise ValidationError("scale", scale, "Scale must be positive")
          
          cmd = get_command()
          
          # Use command line for exports (more reliable than Lua for this)
          args = ["--batch", str(file_path)]
          
          # Add frame range if specified
          if frame_range:
              args.extend(["--frame-range", frame_range])
          
          # Add scale if not 1.0
          if scale != 1.0:
              args.extend(["--scale", str(scale)])
          
          # Add output
          args.extend(["--save-as", str(output_path)])
          
          success, output = cmd.run_command(args)
          
          return f"Sprite exported successfully to {output_path}"
          
      except (ValidationError, AsepriteError) as e:
          return f"Failed to export sprite: {e}"
      except Exception as e:
          return f"Unexpected error: {e}"