FoundationAgents/MetaGPT · error · ValueError

No file open. Use the open_file function first.

Error message

No file open. Use the open_file function first.

What it means

Raised by Editor._check_current_file when a stateful editor operation (goto_line, scroll_down, scroll_up, read, edit, etc.) is called before any file has been opened with open_file or created with create_file. The editor tracks self.current_file, and this guard rejects the None/missing state. It is a usage-order error, not a filesystem error.

Source

Thrown at metagpt/tools/libs/editor.py:195

        try:
            return path.exists()
        except PermissionError:
            return False

    @staticmethod
    def _create_paths(file_path: Path) -> bool:
        try:
            if file_path.parent:
                file_path.parent.mkdir(parents=True, exist_ok=True)
            return True
        except PermissionError:
            return False

    def _check_current_file(self, file_path: Optional[Path] = None) -> bool:
        if file_path is None:
            file_path = self.current_file
        if not file_path or not file_path.is_file():
            raise ValueError("No file open. Use the open_file function first.")
        return True

    @staticmethod
    def _clamp(value, min_value, max_value):
        return max(min_value, min(value, max_value))

    def _lint_file(self, file_path: Path) -> tuple[Optional[str], Optional[int]]:
        """Lint the file at the given path and return a tuple with a boolean indicating if there are errors,
        and the line number of the first error, if any.

        Returns:
            tuple[str | None, int | None]: (lint_error, first_error_line_number)
        """

        linter = Linter(root=self.working_dir)
        lint_error = linter.lint(str(file_path))
        if not lint_error:
            # Linting successful. No issues found.

View on GitHub (pinned to 11cdf466d0)

Solutions

1. Call editor.open_file(path) (or create_file for new files) before goto_line/scroll/read/edit operations
2. If the file should exist but does not, check the path and recreate/relocate it, then open it again
3. Persist and restore self.current_file across steps if you reuse the editor in a multi-turn agent loop

Example fix

// before
editor = Editor()
editor.goto_line(5)  # ValueError: No file open

// after
editor = Editor()
editor.open_file('src/main.py')
editor.goto_line(5)

if editor.current_file is None or not editor.current_file.is_file():
    editor.open_file(str(path))
editor.goto_line(n)

try:
    editor.goto_line(n)
except ValueError as e:
    if 'No file open' in str(e):
        editor.open_file(str(path))  # recover and retry once
    else:
        raise

When it happens

Trigger: Calling editor.goto_line(10), editor.scroll_down(), editor.read(...), or any method that starts with self._check_current_file() on a fresh Editor() instance, or after the previously opened file was deleted/moved so current_file.is_file() is False.

Common situations: Agent pipelines or scripts that instantiate a new Editor per step and forget the open_file call; resuming a session where the file was deleted externally; concurrent runs where another process removed the file between open and edit.

Related errors

• File {path} not found
• Line number must be between 1 and {total_lines}
• File '{filename}' already exists.
• Invalid line number: {start}. Line numbers must be between 1
• Invalid start line number: {start}. Line numbers must be bet

AI-assisted analysis of FoundationAgents/MetaGPT@11cdf466d0 (2026-08-14). Data as JSON: /api/errors/39ff0f953071a394. Report an issue: GitHub.