unslothai/unsloth · warning · ValueError

filename is required when using content_base64

Error message

filename is required when using content_base64

What it means

Pydantic model_validator error on SeedInspectUploadRequest when the legacy inline mode is used (content_base64 present) but filename is not supplied. The backend needs the filename to detect the data format (jsonl/csv/parquet etc.) since inline content has no name of its own.

Source

Thrown at studio/backend/models/data_recipe.py:107

    @model_validator(mode = "after")
    def _check_mutual_exclusivity(self) -> "SeedInspectUploadRequest":
        has_legacy = self.content_base64 is not None
        has_multi = self.file_ids is not None
        if has_legacy and has_multi:
            raise ValueError("Provide either content_base64 or file_ids, not both")
        if not has_legacy and not has_multi:
            raise ValueError("Provide either content_base64 or file_ids")
        if has_multi:
            if len(self.file_ids) == 0:
                raise ValueError("file_ids must not be empty")
            if not self.block_id:
                raise ValueError("block_id is required when using file_ids")
            if self.file_names is None or len(self.file_ids) != len(self.file_names):
                raise ValueError("file_names must be provided and same length as file_ids")
        if has_legacy:
            if not self.filename:
                raise ValueError("filename is required when using content_base64")
        return self


class SeedInspectResponse(BaseModel):
    dataset_name: str
    resolved_path: str
    columns: list[str] = Field(default_factory = list)
    preview_rows: list[dict[str, Any]] = Field(default_factory = list)
    split: str | None = None
    subset: str | None = None
    resolved_paths: list[str] | None = None


class UnstructuredFileUploadResponse(BaseModel):
    file_id: str
    filename: str
    size_bytes: int
    status: str  # "ok" or "error"

View on GitHub (pinned to 203007d190)

Solutions

1. Include 'filename' (exact key, snake-free single word) with the original file name including extension, e.g. 'data.jsonl'.
2. If uploading from an in-memory buffer, synthesize a meaningful name with the right extension for format detection.
3. Ensure the value is a non-empty string.

Example fix

// before
{ "content_base64": "eyJhIjoxfQ==" }
// after
{ "content_base64": "eyJhIjoxfQ==", "filename": "data.jsonl" }

def inline_fields_valid(content_base64: str | None, filename: str | None) -> bool:
    return content_base64 is None or bool(filename and filename.strip())

def has_filename(p: dict) -> bool:
    fn = p.get("filename")
    return isinstance(fn, str) and fn.strip() != ""

When it happens

Trigger: POSTing {"content_base64": "..."} with no 'filename' field (or an empty string), e.g. a client that reads file bytes but forgets to include the original name.

Common situations: Client refactor where the file input's name is dropped; programmatic uploads from buffers that have no natural filename; key named 'file_name' instead of 'filename'.

Related errors

• Provide either content_base64 or file_ids, not both
• Provide either content_base64 or file_ids
• file_ids must not be empty
• block_id is required when using file_ids
• file_names must be provided and same length as file_ids

AI-assisted analysis of unslothai/unsloth@203007d190 (2026-08-15). Data as JSON: /api/errors/c4dca6c8a012ce5e. Report an issue: GitHub.