What causes "File {path} not found" in FoundationAgents/MetaGPT?

Verify the path exists with Path(p).is_file() before calling open_file

FoundationAgents/MetaGPT · error · FileNotFoundError

File {path} not found

Error message

File {path} not found

What it means

Raised by Editor.open_file after path normalization (_try_fix_path) when the resolved path does not point to an existing regular file. The editor deliberately fails fast instead of creating the file: open_file is strictly for existing files, while create_file makes new ones.

Source

Thrown at metagpt/tools/libs/editor.py:297

    def open_file(
        self, path: Union[Path, str], line_number: Optional[int] = 1, context_lines: Optional[int] = None
    ) -> str:
        """Opens the file at the given path in the editor. If line_number is provided, the window will be moved to include that line.
        It only shows the first 100 lines by default! Max `context_lines` supported is 2000, use `scroll up/down`
        to view the file if you want to see more.

        Args:
            path: str: The path to the file to open, preferred absolute path.
            line_number: int | None = 1: The line number to move to. Defaults to 1.
            context_lines: int | None = 100: Only shows this number of lines in the context window (usually from line 1), with line_number as the center (if possible). Defaults to 100.
        """
        if context_lines is None:
            context_lines = self.window

        path = self._try_fix_path(path)

        if not path.is_file():
            raise FileNotFoundError(f"File {path} not found")

        self.current_file = path
        with path.open() as file:
            total_lines = max(1, sum(1 for _ in file))

        if not isinstance(line_number, int) or line_number < 1 or line_number > total_lines:
            raise ValueError(f"Line number must be between 1 and {total_lines}")
        self.current_line = line_number

        # Override WINDOW with context_lines
        if context_lines is None or context_lines < 1:
            context_lines = self.window

        output = self._cur_file_header(path, total_lines)
        output += self._print_window(path, self.current_line, self._clamp(context_lines, 1, 2000))
        self.resource.report(path, "path")
        return output

View on GitHub (pinned to 11cdf466d0)

Solutions

Verify the path exists with Path(p).is_file() before calling open_file
If the file is new, use editor.create_file(path) instead of open_file
Pass an absolute path, or check what base directory _try_fix_path resolves relative paths against

Example fix

// before
editor.open_file('src/utils/helper.py')  # FileNotFoundError

// after
p = Path('src/utils/helper.py')
if p.is_file():
    editor.open_file(str(p))
else:
    editor.create_file(str(p))

Defensive patterns

Strategy: validation

Validate before calling

from pathlib import Path
p = Path(path)
if not p.is_file():
    raise SystemExit(f'missing file: {p.resolve()}')
editor.open_file(str(p))

Type guard

def is_openable_file(p: str) -> bool:
    return Path(p).is_file()

Try / catch

try:
    editor.open_file(path)
except FileNotFoundError:
    editor.create_file(path)  # only if creating is intended

Prevention

Prefer absolute paths so resolution does not depend on CWD
Use create_file for new files and open_file for existing ones
Validate paths at the boundary where LLM/user input enters your pipeline

When it happens

Trigger: editor.open_file('src/app.py') where the file does not exist; passing a directory path; passing a relative path that _try_fix_path resolves against the wrong base directory; typos or wrong-case filenames on case-sensitive filesystems.

Common situations: Relative paths resolved from an unexpected CWD; agent-generated paths that guess at filenames; files not yet created because a previous create/write step failed; symlink targets deleted.

Related errors

AI-assisted analysis of FoundationAgents/MetaGPT@11cdf466d0 (2026-08-14). Data as JSON: /api/errors/b884a20e72a00494. Report an issue: GitHub.