.NET Extensions 10.11: buffered logs can finally keep their scopes

.NET Extensions 10.11.0 shipped to NuGet on October 15, 2026. Most of the AI fixes are small, but one telemetry change closes a gap that has been there since log buffering first appeared: buffered log records lost every ILogger.BeginScope value. You buffered Information logs, an exception fired, you called Flush(), and the records came out without the OrderId, TenantId or request ID you had pushed into scope. Exactly the context you wanted when debugging the failure.

What a flush looked like before

Log buffering lives in Microsoft.Extensions.Telemetry (global buffer) and Microsoft.AspNetCore.Diagnostics.Middleware (per-request buffer). Records that match a rule are held in a circular buffer and only written when you call Flush(). Here is a minimal repro with the JSON console logger, which normally prints scopes when IncludeScopes is on:

var builder = Host.CreateApplicationBuilder();
builder.Logging.ClearProviders();
builder.Logging.AddJsonConsole(o => o.IncludeScopes = true);
builder.Logging.AddGlobalBuffer(o =>
{
    o.Rules.Add(new LogBufferingFilterRule(logLevel: LogLevel.Information));
    o.IncludeScopes = true; // new in 10.11.0, EXTEXP0003
});
using var host = builder.Build();
var logger = host.Services.GetRequiredService<ILogger<Program>>();
var buffer = host.Services.GetRequiredService<GlobalLogBuffer>();

using (logger.BeginScope(new Dictionary<string, object?> { ["OrderId"] = 4711, ["TenantId"] = "contoso" }))
{
    logger.LogInformation("Reserving stock for {Sku}", "SKU-42");
    buffer.Flush();
}

I ran it as a file-based app on SDK 10.0.302. Against Microsoft.Extensions.Telemetry 10.10.0 (without the IncludeScopes line, which does not compile there), the flushed record has no trace of the scope, even though the flush happens inside it:

{"EventId":0,"LogLevel":"Information","Category":"Program","Message":"Reserving stock for SKU-42","Exception":"","State":{"Message":null,"Sku":"SKU-42","{OriginalFormat}":"Reserving stock for {Sku}"}}

On 10.11.0 with IncludeScopes = true:

{"EventId":0,"LogLevel":"Information","Category":"Program","Message":"Reserving stock for SKU-42","Exception":"","State":{"Message":null,"Sku":"SKU-42","OrderId":"4711","TenantId":"contoso","{OriginalFormat}":"Reserving stock for {Sku}"}}

How it works

PR #7813 captures the scopes at the moment a record is buffered, not at flush time, which is what you want: by the time something calls Flush() the original scope is usually long gone. The buffers get an IExternalScopeProvider from DI (shared with ExtendedLoggerFactory) and copy each scope’s name/value pairs into the record.

A few details worth knowing:

• Scopes show up as attributes, not as scopes. IBufferedLogger providers see them in BufferedLogRecord.Attributes; other providers get them merged into the state passed to ILogger.Log. That is why they land in State above rather than in a Scopes array.
• Only scopes that implement IEnumerable<KeyValuePair<string, object?>> are captured. A plain string scope such as BeginScope("Checkout") is skipped, and {OriginalFormat} pairs are dropped. ActivityTrackingOptions scopes (trace ID, span ID) are included.
• It is off by default, experimental under EXTEXP0003, and bindable from configuration. The options are re-read on every buffered record, so a config reload takes effect immediately.

For ASP.NET Core per-request buffering, the same switch exists on PerRequestLogBufferingOptions:

builder.Logging.AddPerIncomingRequestBuffer(o =>
{
    o.Rules.Add(new LogBufferingFilterRule(logLevel: LogLevel.Information));
    o.IncludeScopes = true;
});

Also in 10.11.0

The release fixes an ArgumentNullException in per-request buffering at the end of a request (#7811) and a buffering race caused by a rule-selector cache (#7803). If you use the experimental HTTP latency enricher, AddHttpLatencyTelemetry is now AddHttpServerLatencyTelemetry (#7730). On the AI side, FunctionInvocationContext.Terminate is now honored when the function throws (#7801), and ChatResponseUpdate.Clone keeps ContinuationToken (#7699). The previous release in this series was Microsoft.Extensions.AI 10.10.1.

To upgrade:

dotnet add package Microsoft.Extensions.Telemetry --version 10.11.0

If you buffer logs and correlate them by scope values, turn IncludeScopes on. Without it, the logs you flush when something fails are missing the IDs you need to correlate them.