Philiprehberger.HttpDebugHandler

DelegatingHandler that logs and times every outgoing HttpClient request.

Installation

dotnet add package Philiprehberger.HttpDebugHandler

Usage

using Philiprehberger.HttpDebugHandler;

// Default: writes to Console
var client = new HttpClient(new DebugHandler(new HttpClientHandler()));

// Custom callback
var handler = new DebugHandler(log =>
{
    Console.WriteLine($"{log.Method} {log.RequestUri} => {log.StatusCode} in {log.ElapsedMilliseconds} ms");
})
{
    InnerHandler = new HttpClientHandler()
};

var client = new HttpClient(handler);

var response = await client.GetAsync("https://example.com");
// Output: GET https://example.com/ => 200 in 142 ms

ASP.NET Core / IHttpClientFactory

builder.Services.AddTransient<DebugHandler>();
builder.Services.AddHttpClient("my-client")
    .AddHttpMessageHandler<DebugHandler>();

Body Capture

Enable request and/or response body logging:

var handler = new DebugHandler(log =>
{
    Console.WriteLine($"{log.Method} {log.RequestUri} => {log.StatusCode}");
    if (log.RequestBody is not null)
        Console.WriteLine($"  Request body: {log.RequestBody}");
    if (log.ResponseBody is not null)
        Console.WriteLine($"  Response body: {log.ResponseBody}");
})
{
    InnerHandler = new HttpClientHandler(),
    CaptureRequestBody = true,
    CaptureResponseBody = true,
    MaxBodyCaptureSize = 4096 // optional, default is 65536 (64 KB)
};

Header Logging

Capture request and response headers:

var handler = new DebugHandler(log =>
{
    if (log.RequestHeaders is not null)
        foreach (var h in log.RequestHeaders)
            Console.WriteLine($"  > {h.Key}: {h.Value}");

    if (log.ResponseHeaders is not null)
        foreach (var h in log.ResponseHeaders)
            Console.WriteLine($"  < {h.Key}: {h.Value}");
})
{
    InnerHandler = new HttpClientHandler(),
    CaptureHeaders = true
};

Slow Request Warning

Get notified when a request exceeds a time threshold:

var handler = new DebugHandler(log =>
{
    Console.WriteLine($"{log.Method} {log.RequestUri} => {log.StatusCode} in {log.ElapsedMilliseconds} ms");
})
{
    InnerHandler = new HttpClientHandler(),
    SlowRequestThreshold = TimeSpan.FromSeconds(2),
    OnSlowRequest = log =>
        Console.WriteLine($"SLOW REQUEST: {log.Method} {log.RequestUri} took {log.ElapsedMilliseconds} ms")
};

API

RequestLog

Property	Type	Description
Method	string	HTTP method (GET, POST, ...)
RequestUri	Uri?	Request URL
StatusCode	int	HTTP response status code
ElapsedMilliseconds	long	Round-trip time in milliseconds
Timestamp	DateTimeOffset	UTC time the request was sent
RequestBody	string?	Request body (when CaptureRequestBody is enabled)
ResponseBody	string?	Response body (when CaptureResponseBody is enabled)
RequestHeaders	Dictionary<string, string>?	Request headers (when CaptureHeaders is enabled)
ResponseHeaders	Dictionary<string, string>?	Response headers (when CaptureHeaders is enabled)

DebugHandler

Member	Description
DebugHandler()	Writes formatted log lines to Console
DebugHandler(Action<RequestLog>)	Invokes the provided callback for every request
CaptureRequestBody	bool — capture request body content (default false)
CaptureResponseBody	bool — capture response body content (default false)
CaptureHeaders	bool — capture request and response headers (default false)
MaxBodyCaptureSize	int — max characters to capture per body (default 65536)
SlowRequestThreshold	TimeSpan? — threshold for slow request detection
OnSlowRequest	Action<RequestLog>? — callback for requests exceeding the threshold

Development

dotnet build src/Philiprehberger.HttpDebugHandler.csproj --configuration Release

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License

MIT