microsoft/autogen · error · ValueError

Invalid URI format. It should be a base64 encoded image URI.

Error message

Invalid URI format. It should be a base64 encoded image URI.

What it means

Error "Invalid URI format. It should be a base64 encoded image URI." thrown in microsoft/autogen.

Source

Thrown at python/packages/autogen-core/src/autogen_core/_image.py:52

                        content = await response.read()
                        return Image.from_pil(PILImage.open(content))


            image = asyncio.run(from_url("https://example.com/image"))

    """

    def __init__(self, image: PILImage.Image):
        self.image: PILImage.Image = image.convert("RGB")

    @classmethod
    def from_pil(cls, pil_image: PILImage.Image) -> Image:
        return cls(pil_image)

    @classmethod
    def from_uri(cls, uri: str) -> Image:
        if not re.match(r"data:image/(?:png|jpeg);base64,", uri):
            raise ValueError("Invalid URI format. It should be a base64 encoded image URI.")

        # A URI. Remove the prefix and decode the base64 string.
        base64_data = re.sub(r"data:image/(?:png|jpeg);base64,", "", uri)
        return cls.from_base64(base64_data)

    @classmethod
    def from_base64(cls, base64_str: str) -> Image:
        return cls(PILImage.open(BytesIO(base64.b64decode(base64_str))))

    def to_base64(self) -> str:
        buffered = BytesIO()
        self.image.save(buffered, format="PNG")
        content = buffered.getvalue()
        return base64.b64encode(content).decode("utf-8")

    @classmethod
    def from_file(cls, file_path: Path) -> Image:
        return cls(PILImage.open(file_path))

View on GitHub (pinned to 027ecf0a37)

Solutions

1. Use data:<mediatype>;base64,<data> format

Example fix

Image.from_uri('data:image/png;base64,...')

When it happens

Trigger: Thrown at python/packages/autogen-core/src/autogen_core/_image.py:52 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of microsoft/autogen@027ecf0a37 (2026-08-15). Data as JSON: /api/errors/42e3a26b2d078222. Report an issue: GitHub.