BerriAI/litellm · error · ValueError

No supported extensions for MIME type: {mime_type}. Supporte

Error message

No supported extensions for MIME type: {mime_type}. Supported formats: {supported_doc_formats}

What it means

Bedrock document handling: given a mime_type, LiteLLM tries mimetypes.guess_all_extensions and falls back to its own mime-to-extension table, keeping only extensions in the supported document formats list. If both yield nothing usable, this ValueError is raised — the document's MIME type has no Bedrock-supported extension.

Source

Thrown at litellm/litellm_core_utils/prompt_templates/factory.py:3516

        potential_extensions: Final = mimetypes.guess_all_extensions(mime_type, strict=False)
        valid_extensions = [ext[1:] for ext in potential_extensions if ext[1:] in supported_doc_formats]

        # Fallback to types/files.py if mimetypes doesn't return valid extensions
        #################
        # litellm runs on docker containers and `mimetypes` depends on the installed mimetypes of the OS
        # we fallback to well known mime types in types/files.py if mimetypes doesn't return valid extensions
        if not valid_extensions:
            try:
                fallback_extension: Final = get_file_extension_from_mime_type(mime_type)
                if fallback_extension in supported_doc_formats:
                    valid_extensions = [fallback_extension]
            except ValueError:
                # Neither mimetypes nor files.py could handle this MIME type
                # get_file_extension_from_mime_type raises ValueError if the mime type is not supported
                pass

        if not valid_extensions:
            raise ValueError(
                f"No supported extensions for MIME type: {mime_type}. Supported formats: {supported_doc_formats}"
            )

        # Use first valid extension instead of provided image_format
        return valid_extensions[0]

    @staticmethod
    def _create_bedrock_block(image_bytes: str, mime_type: str, image_format: str) -> BedrockContentBlock:
        """Create appropriate Bedrock content block based on mime type."""
        _blob: Final = BedrockSourceBlock(bytes=image_bytes)

        document_types: Final = ["application", "text"]
        is_document: Final = any(mime_type.startswith(doc_type) for doc_type in document_types)

        supported_video_formats: Final = litellm.AmazonConverseConfig().get_supported_video_types()
        is_video: Final = any(image_format.startswith(video_type) for video_type in supported_video_formats)

        HASH_SAMPLE_BYTES: Final = 64 * 1024  # hash up to 64 KB of data

View on GitHub (pinned to 6c2dcb801b)

Solutions

1. Convert the document to a supported type (typically PDF or plain text) before sending
2. Fix the mime_type/extension on the file so it maps to a supported document format (check the error's supported list)
3. For data files, extract the text and send it as text content instead of a document block

Example fix

# before
block = {"type": "file", "file": {"filename": "data.zip", "file_data": "data:application/zip;base64,<b64>"}}

# after: convert content to PDF/text first
import subprocess
subprocess.run(["libreoffice", "--headless", "--convert-to", "pdf", "report.doc"], check=True)
block = {"type": "file", "file": {"filename": "report.pdf", "file_data": "data:application/pdf;base64,<b64>"}}

import mimetypes

SUPPORTED_DOC_EXTENSIONS = {"pdf", "doc", "docx", "xls", "xlsx", "csv", "md", "txt"}  # align with error's list

def validate_bedrock_document(filename: str, mime_type: str) -> None:
    exts = {e.lstrip(".").lower() for e in mimetypes.guess_all_extensions(mime_type)}
    if not (exts & SUPPORTED_DOC_EXTENSIONS):
        raise ValueError(f"convert {mime_type} to a supported document type (e.g. PDF) before sending")

When it happens

Trigger: Sending a document with an unsupported mime type (e.g. application/x-zip-compressed, application/msword legacy, text/csv variants, proprietary types) to a Bedrock model via the document path; mislabelled content-type on stored files.

Common situations: Uploading DOC/XLS/ZIP/etc. files when only PDF/DOCX/TXT/MD-style document types are supported; files whose extension was stripped so only a weird mime header remains; CSV/TSV sent where a text/* type is accepted only for specific extensions.

Related errors

• Unsupported image format: {image_format}. Supported formats:
• Invalid guardrailConfig={raw_guardrail_config}. Expected for
• guardrailConfig={raw_guardrail_config} is missing 'guardrail
• Invalid S3 URI format: {s3_uri}
• model parameter is required

AI-assisted analysis of BerriAI/litellm@6c2dcb801b (2026-08-15). Data as JSON: /api/errors/9541fc8e67116ce3. Report an issue: GitHub.