bytedance/deer-flow · warning · HTTPException

Symlinked artifacts cannot be edited

Error message

Symlinked artifacts cannot be edited

What it means

HTTP 415 from _load_editable_artifact: os.lstat shows S_ISLNK, i.e. the artifact path is a symbolic link. The atomic replace strategy (mkstemp + rename in the same directory) would replace the link itself, not the target, silently changing semantics — so symlinks are excluded from editing.

Source

Thrown at backend/app/gateway/routers/artifacts.py:83

        yield


def _normalize_editable_artifact_path(path: str) -> str:
    stripped = path.lstrip("/")
    if not stripped.startswith(_EDITABLE_OUTPUTS_PREFIX):
        raise HTTPException(status_code=400, detail="Only files in /mnt/user-data/outputs can be edited")
    if ".skill/" in stripped or stripped.endswith(".skill"):
        raise HTTPException(status_code=415, detail="Skill archives cannot be edited in the artifacts panel")
    return f"/{stripped}"


def _load_editable_artifact(actual_path: Path, path: str, expected_sha256: str) -> tuple[bytes, os.stat_result]:
    try:
        file_stat = os.lstat(actual_path)
    except FileNotFoundError:
        raise HTTPException(status_code=404, detail=f"Artifact not found: {path}") from None
    if stat.S_ISLNK(file_stat.st_mode):
        raise HTTPException(status_code=415, detail="Symlinked artifacts cannot be edited")
    if not stat.S_ISREG(file_stat.st_mode):
        raise HTTPException(status_code=400, detail=f"Path is not a file: {path}")
    if file_stat.st_size > MAX_EDITABLE_ARTIFACT_BYTES:
        raise HTTPException(status_code=413, detail="Artifact is too large to edit")

    current = actual_path.read_bytes()
    if len(current) > MAX_EDITABLE_ARTIFACT_BYTES:
        raise HTTPException(status_code=413, detail="Artifact is too large to edit")
    if b"\x00" in current:
        raise HTTPException(status_code=415, detail="Binary artifacts cannot be edited")
    try:
        current.decode("utf-8")
    except UnicodeDecodeError:
        raise HTTPException(status_code=415, detail="Only UTF-8 text artifacts can be edited") from None

    current_sha256 = hashlib.sha256(current).hexdigest()
    if current_sha256 != expected_sha256:
        raise HTTPException(status_code=412, detail="Artifact changed since it was opened")

View on GitHub (pinned to 1dd6ba1acb)

Solutions

1. Replace the symlink with the real file (cp -L) if editing is required, then retry
2. Edit the canonical target through its own outputs path if it is itself under outputs
3. Keep symlinked artifacts read-only in UIs and surface the 415 detail to the user

import os, stat

def is_editable_file(actual_path: str) -> bool:
    try:
        st = os.lstat(actual_path)
    except OSError:
        return False
    return not stat.S_ISLNK(st.st_mode) and stat.S_ISREG(st.st_mode)

if resp.status_code == 415 and "Symlinked" in resp.text:
    # resolve or materialize the real file, then re-open editor
    materialize_real_file(path)

When it happens

Trigger: PUT edit-artifact where the outputs path is a symlink (agent created ln -s to share a file across output paths, or an operator symlinked outputs into the directory).

Common situations: Agents using symlinks to deduplicate large outputs, deployments where /mnt/user-data/outputs is itself reached through links, or attempts to edit a file whose canonical content lives outside outputs via a link.

Related errors

• Skill archives cannot be edited in the artifacts panel
• Path is not a file: {path}
• Binary artifacts cannot be edited
• Only UTF-8 text artifacts can be edited
• Binary content cannot be saved as an artifact

AI-assisted analysis of bytedance/deer-flow@1dd6ba1acb (2026-08-14). Data as JSON: /api/errors/e506bb35581814fc. Report an issue: GitHub.