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Merged
merged 3 commits into from
Oct 28, 2025
Merged

Adds OpenAIUsageDebuggingPlugin. Closes #1413 #1427

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699426e
Adds OpenAIUsageDebuggingPlugin. Closes #1413
waldekmastykarz Oct 12, 2025
2c917b2
Merge branch 'main' into llmusagedebug
garrytrinder Oct 28, 2025
947eb40
Make OpenAI usage logging more robust by safely parsing headers
waldekmastykarz Oct 28, 2025
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100 changes: 100 additions & 0 deletions DevProxy.Abstractions/LanguageModel/OpenAIModels.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -2,6 +2,9 @@
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

using DevProxy.Abstractions.Utils;
using Microsoft.Extensions.Logging;
using System.Text.Json;
using System.Text.Json.Serialization;

namespace DevProxy.Abstractions.LanguageModel;
Expand All @@ -20,6 +23,95 @@ public class OpenAIRequest
public double? Temperature { get; set; }
[JsonPropertyName("top_p")]
public double? TopP { get; set; }

public static bool TryGetOpenAIRequest(string content, ILogger logger, out OpenAIRequest? request)
{
logger.LogTrace("{Method} called", nameof(TryGetOpenAIRequest));

request = null;

if (string.IsNullOrEmpty(content))
{
logger.LogDebug("Request content is empty or null");
return false;
}

try
{
logger.LogDebug("Checking if the request is an OpenAI request...");

var rawRequest = JsonSerializer.Deserialize<JsonElement>(content, ProxyUtils.JsonSerializerOptions);

// Check for completion request (has "prompt", but not specific to image)
if (rawRequest.TryGetProperty("prompt", out _) &&
!rawRequest.TryGetProperty("size", out _) &&
!rawRequest.TryGetProperty("n", out _))
{
logger.LogDebug("Request is a completion request");
request = JsonSerializer.Deserialize<OpenAICompletionRequest>(content, ProxyUtils.JsonSerializerOptions);
return true;
}

// Chat completion request
if (rawRequest.TryGetProperty("messages", out _))
{
logger.LogDebug("Request is a chat completion request");
request = JsonSerializer.Deserialize<OpenAIChatCompletionRequest>(content, ProxyUtils.JsonSerializerOptions);
return true;
}

// Embedding request
if (rawRequest.TryGetProperty("input", out _) &&
rawRequest.TryGetProperty("model", out _) &&
!rawRequest.TryGetProperty("voice", out _))
{
logger.LogDebug("Request is an embedding request");
request = JsonSerializer.Deserialize<OpenAIEmbeddingRequest>(content, ProxyUtils.JsonSerializerOptions);
return true;
}

// Image generation request
if (rawRequest.TryGetProperty("prompt", out _) &&
(rawRequest.TryGetProperty("size", out _) || rawRequest.TryGetProperty("n", out _)))
{
logger.LogDebug("Request is an image generation request");
request = JsonSerializer.Deserialize<OpenAIImageRequest>(content, ProxyUtils.JsonSerializerOptions);
return true;
}

// Audio transcription request
if (rawRequest.TryGetProperty("file", out _))
{
logger.LogDebug("Request is an audio transcription request");
request = JsonSerializer.Deserialize<OpenAIAudioRequest>(content, ProxyUtils.JsonSerializerOptions);
return true;
}

// Audio speech synthesis request
if (rawRequest.TryGetProperty("input", out _) && rawRequest.TryGetProperty("voice", out _))
{
logger.LogDebug("Request is an audio speech synthesis request");
request = JsonSerializer.Deserialize<OpenAIAudioSpeechRequest>(content, ProxyUtils.JsonSerializerOptions);
return true;
}

// Fine-tuning request
if (rawRequest.TryGetProperty("training_file", out _))
{
logger.LogDebug("Request is a fine-tuning request");
request = JsonSerializer.Deserialize<OpenAIFineTuneRequest>(content, ProxyUtils.JsonSerializerOptions);
return true;
}

logger.LogDebug("Request is not an OpenAI request.");
return false;
}
catch (JsonException ex)
{
logger.LogDebug(ex, "Failed to deserialize OpenAI request.");
return false;
}
}
}

public class OpenAIResponse : ILanguageModelCompletionResponse
Expand Down Expand Up @@ -82,10 +174,18 @@ public class OpenAIResponseUsage
public long CompletionTokens { get; set; }
[JsonPropertyName("prompt_tokens")]
public long PromptTokens { get; set; }
[JsonPropertyName("prompt_tokens_details")]
public PromptTokenDetails? PromptTokensDetails { get; set; }
[JsonPropertyName("total_tokens")]
public long TotalTokens { get; set; }
}

public class PromptTokenDetails
{
[JsonPropertyName("cached_tokens")]
public long CachedTokens { get; set; }
}

public class OpenAIResponsePromptFilterResult
{
[JsonPropertyName("content_filter_results")]
Expand Down
154 changes: 4 additions & 150 deletions DevProxy.Plugins/Inspection/OpenAITelemetryPlugin.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -7,6 +7,7 @@
using DevProxy.Abstractions.Plugins;
using DevProxy.Abstractions.Proxy;
using DevProxy.Abstractions.Utils;
using DevProxy.Plugins.Utils;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
Expand All @@ -19,7 +20,6 @@
using System.Diagnostics;
using System.Diagnostics.Metrics;
using System.Text.Json;
using Titanium.Web.Proxy.Http;

namespace DevProxy.Plugins.Inspection;

Expand Down Expand Up @@ -108,7 +108,7 @@ public override Task BeforeRequestAsync(ProxyRequestArgs e, CancellationToken ca
return Task.CompletedTask;
}

if (!TryGetOpenAIRequest(request.BodyString, out var openAiRequest) || openAiRequest is null)
if (!OpenAIRequest.TryGetOpenAIRequest(request.BodyString, Logger, out var openAiRequest) || openAiRequest is null)
{
Logger.LogRequest("Skipping non-OpenAI request", MessageType.Skipped, new(e.Session));
return Task.CompletedTask;
Expand Down Expand Up @@ -323,9 +323,9 @@ private void ProcessSuccessResponse(Activity activity, ProxyResponseArgs e)
}

var bodyString = response.BodyString;
if (IsStreamingResponse(response))
if (HttpUtils.IsStreamingResponse(response, Logger))
{
bodyString = GetBodyFromStreamingResponse(response);
bodyString = HttpUtils.GetBodyFromStreamingResponse(response, Logger);
}

AddResponseTypeSpecificTags(activity, openAiRequest, bodyString);
Expand Down Expand Up @@ -895,95 +895,6 @@ private void RecordUsageMetrics(Activity activity, OpenAIRequest request, OpenAI
Logger.LogTrace("RecordUsageMetrics() finished");
}

private bool TryGetOpenAIRequest(string content, out OpenAIRequest? request)
{
Logger.LogTrace("TryGetOpenAIRequest() called");

request = null;

if (string.IsNullOrEmpty(content))
{
Logger.LogDebug("Request content is empty or null");
return false;
}

try
{
Logger.LogDebug("Checking if the request is an OpenAI request...");

var rawRequest = JsonSerializer.Deserialize<JsonElement>(content, ProxyUtils.JsonSerializerOptions);

// Check for completion request (has "prompt", but not specific to image)
if (rawRequest.TryGetProperty("prompt", out _) &&
!rawRequest.TryGetProperty("size", out _) &&
!rawRequest.TryGetProperty("n", out _))
{
Logger.LogDebug("Request is a completion request");
request = JsonSerializer.Deserialize<OpenAICompletionRequest>(content, ProxyUtils.JsonSerializerOptions);
return true;
}

// Chat completion request
if (rawRequest.TryGetProperty("messages", out _))
{
Logger.LogDebug("Request is a chat completion request");
request = JsonSerializer.Deserialize<OpenAIChatCompletionRequest>(content, ProxyUtils.JsonSerializerOptions);
return true;
}

// Embedding request
if (rawRequest.TryGetProperty("input", out _) &&
rawRequest.TryGetProperty("model", out _) &&
!rawRequest.TryGetProperty("voice", out _))
{
Logger.LogDebug("Request is an embedding request");
request = JsonSerializer.Deserialize<OpenAIEmbeddingRequest>(content, ProxyUtils.JsonSerializerOptions);
return true;
}

// Image generation request
if (rawRequest.TryGetProperty("prompt", out _) &&
(rawRequest.TryGetProperty("size", out _) || rawRequest.TryGetProperty("n", out _)))
{
Logger.LogDebug("Request is an image generation request");
request = JsonSerializer.Deserialize<OpenAIImageRequest>(content, ProxyUtils.JsonSerializerOptions);
return true;
}

// Audio transcription request
if (rawRequest.TryGetProperty("file", out _))
{
Logger.LogDebug("Request is an audio transcription request");
request = JsonSerializer.Deserialize<OpenAIAudioRequest>(content, ProxyUtils.JsonSerializerOptions);
return true;
}

// Audio speech synthesis request
if (rawRequest.TryGetProperty("input", out _) && rawRequest.TryGetProperty("voice", out _))
{
Logger.LogDebug("Request is an audio speech synthesis request");
request = JsonSerializer.Deserialize<OpenAIAudioSpeechRequest>(content, ProxyUtils.JsonSerializerOptions);
return true;
}

// Fine-tuning request
if (rawRequest.TryGetProperty("training_file", out _))
{
Logger.LogDebug("Request is a fine-tuning request");
request = JsonSerializer.Deserialize<OpenAIFineTuneRequest>(content, ProxyUtils.JsonSerializerOptions);
return true;
}

Logger.LogDebug("Request is not an OpenAI request.");
return false;
}
catch (JsonException ex)
{
Logger.LogDebug(ex, "Failed to deserialize OpenAI request.");
return false;
}
}

private static string GetOperationName(OpenAIRequest request)
{
if (request == null)
Expand All @@ -1004,63 +915,6 @@ private static string GetOperationName(OpenAIRequest request)
};
}

private bool IsStreamingResponse(Response response)
{
Logger.LogTrace("{Method} called", nameof(IsStreamingResponse));
var contentType = response.Headers.FirstOrDefault(h => h.Name.Equals("content-type", StringComparison.OrdinalIgnoreCase))?.Value;
if (string.IsNullOrEmpty(contentType))
{
Logger.LogDebug("No content-type header found");
return false;
}

var isStreamingResponse = contentType.Contains("text/event-stream", StringComparison.OrdinalIgnoreCase);
Logger.LogDebug("IsStreamingResponse: {IsStreamingResponse}", isStreamingResponse);

Logger.LogTrace("{Method} finished", nameof(IsStreamingResponse));
return isStreamingResponse;
}

private string GetBodyFromStreamingResponse(Response response)
{
Logger.LogTrace("{Method} called", nameof(GetBodyFromStreamingResponse));

// default to the whole body
var bodyString = response.BodyString;

var chunks = bodyString.Split("\n\n", StringSplitOptions.RemoveEmptyEntries);
if (chunks.Length == 0)
{
Logger.LogDebug("No chunks found in the response body");
return bodyString;
}

// check if the last chunk is `data: [DONE]`
var lastChunk = chunks.Last().Trim();
if (lastChunk.Equals("data: [DONE]", StringComparison.OrdinalIgnoreCase))
{
// get next to last chunk
var chunk = chunks.Length > 1 ? chunks[^2].Trim() : string.Empty;
if (chunk.StartsWith("data: ", StringComparison.OrdinalIgnoreCase))
{
// remove the "data: " prefix
bodyString = chunk["data: ".Length..].Trim();
Logger.LogDebug("Last chunk starts with 'data: ', using the last chunk as the body: {BodyString}", bodyString);
}
else
{
Logger.LogDebug("Last chunk does not start with 'data: ', using the whole body");
}
}
else
{
Logger.LogDebug("Last chunk is not `data: [DONE]`, using the whole body");
}

Logger.LogTrace("{Method} finished", nameof(GetBodyFromStreamingResponse));
return bodyString;
}

public void Dispose()
{
_loader?.Dispose();
Expand Down
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