microsoft/autogen · error · HttpRequestException

Failed to download the image from {uri}

Error message

Failed to download the image from {uri}

What it means

Error "Failed to download the image from {uri}" thrown in microsoft/autogen.

Source

Thrown at dotnet/src/AutoGen.Anthropic/Middleware/AnthropicMessageConnector.cs:228

        {
            return new ImageSource
            {
                MediaType = imageMessage.Data.MediaType,
                Data = Convert.ToBase64String(imageMessage.Data.ToArray())
            };
        }

        if (imageMessage.Url is null)
        {
            throw new InvalidOperationException("Invalid ImageMessage, the data or url must be provided");
        }

        var uri = new Uri(imageMessage.Url);
        using var client = new HttpClient();
        var response = client.GetAsync(uri).Result;
        if (!response.IsSuccessStatusCode)
        {
            throw new HttpRequestException($"Failed to download the image from {uri}");
        }

        return new ImageSource
        {
            MediaType = "image/jpeg",
            Data = Convert.ToBase64String(await response.Content.ReadAsByteArrayAsync())
        };
    }

    private IEnumerable<IMessage> ProcessToolCallMessage(ToolCallMessage toolCallMessage, IAgent _)
    {
        var chatMessage = new ChatMessage("assistant", new List<ContentBase>());
        foreach (var toolCall in toolCallMessage.ToolCalls)
        {
            chatMessage.AddContent(new ToolUseContent
            {
                Id = toolCall.ToolCallId,
                Name = toolCall.FunctionName,

View on GitHub (pinned to 027ecf0a37)

Solutions

1. Verify the URI is reachable and returns an image; add retry/auth as needed

Example fix

Check response.EnsureSuccessStatusCode() and that Content-Type is an image

When it happens

Trigger: Thrown at dotnet/src/AutoGen.Anthropic/Middleware/AnthropicMessageConnector.cs:228 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/5db6bb7f484c89f0. Report an issue: GitHub.