agentscope-ai/agentscope · error · ValueError

Unsupported audio source type: {type(source)}

Error message

Unsupported audio source type: {type(source)}

What it means

DashScope formatter raises this ValueError in _format_audio_source when an audio block's source object is neither a URLSource nor a Base64Source (e.g. a LocalFileSource or raw string/bytes). The formatter dispatches on isinstance checks for those two source types; anything else falls through to this raise. It indicates the message's audio data block was built with a source type unsupported by the DashScope backend formatter.

Source

Thrown at src/agentscope/formatter/_dashscope_formatter.py:216

                with open(local_path, "rb") as f:
                    encoded = base64.b64encode(f.read()).decode("utf-8")
                return {
                    "type": "input_audio",
                    "input_audio": {
                        "data": f"data:;base64,{encoded}",
                        "format": fmt,
                    },
                }
            else:
                return {
                    "type": "input_audio",
                    "input_audio": {
                        "data": url_str,
                        "format": fmt,
                    },
                }

        raise ValueError(f"Unsupported audio source type: {type(source)}")


class DashScopeChatFormatter(_DashScopeFormatterBase):
    """The DashScope formatter class for chatbot scenario (OpenAI-compatible
    format), where only a user and an agent are involved. We use the ``role``
    field to identify different entities in the conversation.

    This formatter outputs messages in the OpenAI Chat Completions format,
    with DashScope-specific extensions for video (``video_url``) and
    thinking (``reasoning_content``).
    """

    # pylint: disable=too-many-branches
    async def format(
        self,
        msgs: list[Msg],
    ) -> list[dict[str, Any]]:
        """Format message objects into DashScope OpenAI-compatible format.

View on GitHub (pinned to e90f1c7592)

Solutions

1. Convert the audio to a Base64Source before formatting (read the file, base64-encode it, set media_type e.g. 'audio/wav')
2. If the file is hosted, use a URLSource pointing to the remote audio instead
3. Check the source type before calling format() and give a clear user-facing error or fallback to text
4. If you control the pipeline, normalize all media blocks to URLSource/Base64Source at message-construction time

Example fix

# before
msg = Msg("user", [AudioBlock(source=LocalFileSource(path="clip.wav"), alt="clip")])
formatter.format(msg)

# after
import base64
data = base64.b64encode(open("clip.wav", "rb").read()).decode()
msg = Msg("user", [AudioBlock(source=Base64Source(data=data, media_type="audio/wav"), alt="clip")])
formatter.format(msg)

from agentscope.message import URLSource, Base64Source
src = block.source
assert isinstance(src, (URLSource, Base64Source)), f"audio source must be URL/Base64, got {type(src)}"

def is_dashscope_audio_source(src) -> bool:
    return isinstance(src, (URLSource, Base64Source))

try:
    formatted = formatter.format(msgs)
except ValueError as e:
    if "Unsupported audio source type" in str(e):
        # strip audio blocks or convert to base64, then retry
        ...
    raise

When it happens

Trigger: Calling format() on a DashScope formatter with a Msg containing an AudioBlock whose source is a LocalFileSource (or plain path string/bytes) instead of URLSource/Base64Source; any custom source class not derived from the two supported types.

Common situations: Loading audio from a local file path and passing the path or LocalFileSource directly into the audio block; migrating messages between model formatters (OpenAI/Ollama accept local files, DashScope does not); constructing blocks from dicts without going through the source factory helpers.

Related errors

• Unsupported audio source type: {type(source)}.
• Unsupported source type: {type(source)}
• Unsupported image source type: {type(source)}
• Unsupported source type: {type(source)}
• Unsupported image source type: {type(source)}

AI-assisted analysis of agentscope-ai/agentscope@e90f1c7592 (2026-08-28). Data as JSON: /api/errors/1d4c93b87fe45611. Report an issue: GitHub.