Add articles on logging and progress (#717)

* Add articles on logging and progress
* Address comments in PR review
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Mike Kistler 2025-08-25 20:51:41 -05:00 • committed by GitHub
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---
title: Elicitation
author: mikekistler
description: Learn about the telemetry collected by the HttpRepl.
description: Enable interactive AI experiences by requesting user input during tool execution.
uid: elicitation
---
## Elicitation
The **elicitation** feature allows servers to request additional information from users during interactions. This enables more dynamic and interactive AI experiences, making it easier to gather necessary context before executing tasks.
## Server Support for Elicitation
### Server Support for Elicitation
Servers request structured data from users with the [ElicitAsync] extension method on [IMcpServer].
The C# SDK registers an instance of [IMcpServer] with the dependency injection container,
@ -27,7 +29,7 @@ The following example demonstrates how a server could request a boolean response
[!code-csharp[](samples/server/Tools/InteractiveTools.cs?name=snippet_GuessTheNumber)]
## Client Support for Elicitation
### Client Support for Elicitation
Elicitation is an optional feature so clients declare their support for it in their capabilities as part of the `initialize` request. In the MCP C# SDK, this is done by configuring an [ElicitationHandler] in the [McpClientOptions]:

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---
title: Logging
author: mikekistler
description: How to use the logging feature in the MCP C# SDK.
uid: logging
---
## Logging
MCP servers may expose log messages to clients through the [Logging utility].
[Logging utility]: https://modelcontextprotocol.io/specification/2025-06-18/server/utilities/logging
This document describes how to implement logging in MCP servers and how clients can consume log messages.
### Logging Levels
MCP uses the logging levels defined in [RFC 5424](https://tools.ietf.org/html/rfc5424).
The MCP C# SDK uses the standard .NET [ILogger] and [ILoggerProvider] abstractions, which support a slightly
different set of logging levels. Here's the levels and how they map to standard .NET logging levels.
| Level | .NET | Description | Example Use Case |
|-----------|------|-----------------------------------|------------------------------|
| debug | ✓ | Detailed debugging information | Function entry/exit points |
| info | ✓ | General informational messages | Operation progress updates |
| notice | | Normal but significant events | Configuration changes |
| warning | ✓ | Warning conditions | Deprecated feature usage |
| error | ✓ | Error conditions | Operation failures |
| critical | ✓ | Critical conditions | System component failures |
| alert | | Action must be taken immediately | Data corruption detected |
| emergency | | System is unusable | |
**Note:** .NET's [ILogger] also supports a `Trace` level (more verbose than Debug) log level.
As there is no equivalent level in the MCP logging levels, Trace level logs messages are silently
dropped when sending messages to the client.
[ILogger]: https://learn.microsoft.com/dotnet/api/microsoft.extensions.logging.ilogger
[ILoggerProvider]: https://learn.microsoft.com/dotnet/api/microsoft.extensions.logging.iloggerprovider
### Server configuration and logging
MCP servers that implement the Logging utility must declare this in the capabilities sent in the
[Initialization] phase at the beginning of the MCP session.
[Initialization]: https://modelcontextprotocol.io/specification/2025-06-18/basic/lifecycle#initialization
Servers built with the C# SDK always declare the logging capability. Doing so does not obligate the server
to send log messages -- only allows it. Note that stateless MCP servers may not be capable of sending log
messages as there may not be an open connection to the client on which the log messages could be sent.
The C# SDK provides an extension method [WithSetLoggingLevelHandler] on [IMcpServerBuilder] to allow the
server to perform any special logic it wants to perform when a client sets the logging level. However, the
SDK already takes care of setting the [LoggingLevel] in the [IMcpServer], so most servers will not need to
implement this.
[IMcpServer]: https://modelcontextprotocol.github.io/csharp-sdk/api/ModelContextProtocol.Server.IMcpServer.html
[IMcpServerBuilder]: https://modelcontextprotocol.github.io/csharp-sdk/api/Microsoft.Extensions.DependencyInjection.IMcpServerBuilder.html
[WithSetLoggingLevelHandler]: https://modelcontextprotocol.github.io/csharp-sdk/api/Microsoft.Extensions.DependencyInjection.McpServerBuilderExtensions.html#Microsoft_Extensions_DependencyInjection_McpServerBuilderExtensions_WithSetLoggingLevelHandler_Microsoft_Extensions_DependencyInjection_IMcpServerBuilder_System_Func_ModelContextProtocol_Server_RequestContext_ModelContextProtocol_Protocol_SetLevelRequestParams__System_Threading_CancellationToken_System_Threading_Tasks_ValueTask_ModelContextProtocol_Protocol_EmptyResult___
[LoggingLevel]: https://modelcontextprotocol.github.io/csharp-sdk/api/ModelContextProtocol.Server.IMcpServer.html#ModelContextProtocol_Server_IMcpServer_LoggingLevel
MCP Servers using the MCP C# SDK can obtain an [ILoggerProvider] from the IMcpServer [AsClientLoggerProvider] extension method,
and from that can create an [ILogger] instance for logging messages that should be sent to the MCP client.
[!code-csharp[](samples/server/Tools/LoggingTools.cs?name=snippet_LoggingConfiguration)]
[ILoggerProvider]: https://learn.microsoft.com/dotnet/api/microsoft.extensions.logging.iloggerprovider
[AsClientLoggerProvider]: https://modelcontextprotocol.github.io/csharp-sdk/api/ModelContextProtocol.Server.McpServerExtensions.html#ModelContextProtocol_Server_McpServerExtensions_AsClientLoggerProvider_ModelContextProtocol_Server_IMcpServer_
[ILogger]: https://learn.microsoft.com/dotnet/api/microsoft.extensions.logging.ilogger
### Client support for logging
When the server indicates that it supports logging, clients should configure
the logging level to specify which messages the server should send to the client.
Clients should check if the server supports logging by checking the [Logging] property of the [ServerCapabilities] field of [IMcpClient].
[IMcpClient]: https://modelcontextprotocol.github.io/csharp-sdk/api/ModelContextProtocol.Client.IMcpClient.html
[ServerCapabilities]: https://modelcontextprotocol.github.io/csharp-sdk/api/ModelContextProtocol.Client.IMcpClient.html#ModelContextProtocol_Client_IMcpClient_ServerCapabilities
[Logging]: https://modelcontextprotocol.github.io/csharp-sdk/api/ModelContextProtocol.Protocol.ServerCapabilities.html#ModelContextProtocol_Protocol_ServerCapabilities_Logging
[!code-csharp[](samples/client/Program.cs?name=snippet_LoggingCapabilities)]
If the server supports logging, the client should set the level of log messages it wishes to receive with
the [SetLoggingLevel] method on [IMcpClient]. If the client does not set a logging level, the server might choose
to send all log messages or none -- this is not specified in the protocol -- so it is important that the client
sets a logging level to ensure it receives the desired log messages and only those messages.
The `loggingLevel` set by the client is an MCP logging level.
See the [Logging Levels](#logging-levels) section above for the mapping between MCP and .NET logging levels.
[SetLoggingLevel]: https://modelcontextprotocol.github.io/csharp-sdk/api/ModelContextProtocol.Client.McpClientExtensions.html#ModelContextProtocol_Client_McpClientExtensions_SetLoggingLevel_ModelContextProtocol_Client_IMcpClient_Microsoft_Extensions_Logging_LogLevel_System_Threading_CancellationToken_
[!code-csharp[](samples/client/Program.cs?name=snippet_LoggingLevel)]
Lastly, the client must configure a notification handler for [NotificationMethods.LoggingMessageNotification] notifications.
The following example simply writes the log messages to the console.
[NotificationMethods.LoggingMessageNotification]: https://modelcontextprotocol.github.io/csharp-sdk/api/ModelContextProtocol.Protocol.NotificationMethods.html#ModelContextProtocol_Protocol_NotificationMethods_LoggingMessageNotification
[!code-csharp[](samples/client/Program.cs?name=snippet_LoggingHandler)]

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<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup>
<OutputType>Exe</OutputType>
<TargetFramework>net9.0</TargetFramework>
<ImplicitUsings>enable</ImplicitUsings>
<Nullable>enable</Nullable>
</PropertyGroup>
<ItemGroup>
<PackageReference Include="ModelContextProtocol.Core" Version="0.3.0-preview.3" />
</ItemGroup>
</Project>

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using ModelContextProtocol.Protocol;
using ModelContextProtocol.Client;
using System.Text.Json;
var endpoint = Environment.GetEnvironmentVariable("ENDPOINT") ?? "http://localhost:3001";
var clientTransport = new SseClientTransport(new()
{
Endpoint = new Uri(endpoint),
TransportMode = HttpTransportMode.StreamableHttp,
});
await using var mcpClient = await McpClientFactory.CreateAsync(clientTransport);
// <snippet_LoggingCapabilities>
// Verify that the server supports logging
if (mcpClient.ServerCapabilities.Logging is null)
{
Console.WriteLine("Server does not support logging.");
return;
}
// </snippet_LoggingCapabilities>
// Get the first argument if it was specified
var firstArgument = args.Length > 0 ? args[0] : null;
if (firstArgument is not null)
{
// Set the logging level to the value from the first argument
if (Enum.TryParse<LoggingLevel>(firstArgument, true, out var loggingLevel))
{
// <snippet_LoggingLevel>
await mcpClient.SetLoggingLevel(loggingLevel);
// </snippet_LoggingLevel>
}
else
{
Console.WriteLine($"Invalid logging level: {firstArgument}");
// Print a list of valid logging levels
Console.WriteLine("Valid logging levels are:");
foreach (var level in Enum.GetValues<LoggingLevel>())
{
Console.WriteLine($" - {level}");
}
}
}
// <snippet_LoggingHandler>
mcpClient.RegisterNotificationHandler(NotificationMethods.LoggingMessageNotification,
(notification, ct) =>
{
if (JsonSerializer.Deserialize<LoggingMessageNotificationParams>(notification.Params) is { } ln)
{
Console.WriteLine($"[{ln.Level}] {ln.Logger} {ln.Data}");
}
else
{
Console.WriteLine($"Received unexpected logging notification: {notification.Params}");
}
return default;
});
// </snippet_LoggingHandler>
// Now call the "logging_tool" tool
await mcpClient.CallToolAsync("logging_tool");

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<Project Sdk="Microsoft.NET.Sdk.Web">
<PropertyGroup>
<TargetFramework>net9.0</TargetFramework>
<Nullable>enable</Nullable>
<ImplicitUsings>enable</ImplicitUsings>
</PropertyGroup>
<ItemGroup>
<PackageReference Include="ModelContextProtocol.AspNetCore" Version="0.3.0-preview.3" />
</ItemGroup>
</Project>

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@HostAddress = http://localhost:3001
POST {{HostAddress}}/
Accept: application/json, text/event-stream
Content-Type: application/json
{
"jsonrpc": "2.0",
"id": 1,
"method": "initialize",
"params": {
"clientInfo": {
"name": "RestClient",
"version": "0.1.0"
},
"capabilities": {},
"protocolVersion": "2025-06-18"
}
}
###
@SessionId = JCo3W4Q7KA_evyWoFE5qwA
###
POST {{HostAddress}}/
Accept: application/json, text/event-stream
Content-Type: application/json
MCP-Protocol-Version: 2025-06-18
Mcp-Session-Id: {{SessionId}}
{
"jsonrpc": "2.0",
"id": 2,
"method": "tools/call",
"params": {
"name": "logging_tool"
}
}

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using Logging.Tools;
var builder = WebApplication.CreateBuilder(args);
// Add services to the container.
builder.Services.AddMcpServer()
.WithHttpTransport(options =>
options.IdleTimeout = Timeout.InfiniteTimeSpan // Never timeout
)
.WithTools<LoggingTools>();
// .WithSetLoggingLevelHandler(async (ctx, ct) => new EmptyResult());
var app = builder.Build();
app.UseHttpsRedirection();
app.MapMcp();
app.Run();

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{
"$schema": "https://json.schemastore.org/launchsettings.json",
"profiles": {
"http": {
"commandName": "Project",
"dotnetRunMessages": true,
"launchBrowser": false,
"applicationUrl": "http://localhost:3001",
"environmentVariables": {
"ASPNETCORE_ENVIRONMENT": "Development"
}
},
"https": {
"commandName": "Project",
"dotnetRunMessages": true,
"launchBrowser": false,
"applicationUrl": "https://localhost:7207;http://localhost:3001",
"environmentVariables": {
"ASPNETCORE_ENVIRONMENT": "Development"
}
}
}
}

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using System.ComponentModel;
using ModelContextProtocol.Protocol;
using ModelContextProtocol.Server;
namespace Logging.Tools;
[McpServerToolType]
public class LoggingTools
{
[McpServerTool, Description("Demonstrates a tool that produces log messages")]
public static async Task<string> LoggingTool(
RequestContext<CallToolRequestParams> context,
int duration = 10,
int steps = 10)
{
var progressToken = context.Params?.ProgressToken;
var stepDuration = duration / steps;
// <snippet_LoggingConfiguration >
ILoggerProvider loggerProvider = context.Server.AsClientLoggerProvider();
ILogger logger = loggerProvider.CreateLogger("LoggingTools");
// </snippet_LoggingConfiguration>
for (int i = 1; i <= steps; i++)
{
await Task.Delay(stepDuration * 1000);
try
{
logger.LogCritical("A critial log message");
logger.LogError("An error log message");
logger.LogWarning("A warning log message");
logger.LogInformation("An informational log message");
logger.LogDebug("A debug log message");
logger.LogTrace("A trace log message");
}
catch (Exception ex)
{
logger.LogError(ex, "An error occurred while logging messages");
}
}
return $"Long running tool completed. Duration: {duration} seconds. Steps: {steps}.";
}
}

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{
"Logging": {
"LogLevel": {
"Default": "Information",
"Microsoft.AspNetCore": "Warning"
}
}
}

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{
"Logging": {
"LogLevel": {
"Default": "Information",
"Microsoft.AspNetCore": "Warning"
}
},
"AllowedHosts": "*"
}

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---
title: Progress
author: mikekistler
description:
uid: progress
---
## Progress
The Model Context Protocol (MCP) supports [progress tracking] for long-running operations through notification messages.
[progress tracking]: https://modelcontextprotocol.io/specification/2025-06-18/basic/utilities/progress
Typically progress tracking is supported by server tools that perform operations that take a significant amount of time to complete, such as image generation or complex calculations.
However, progress tracking is defined in the MCP specification as a general feature that can be implemented for any request that is handled by either a server or a client.
This project illustrates the common case of a server tool that performs a long-running operation and sends progress updates to the client.
### Server Implementation
When processing a request, the server can use the [sendNotificationAsync] extension method of [IMcpServer] to send progress updates,
specifying `"notifications/progress"` as the notification method name.
The C# SDK registers an instance of [IMcpServer] with the dependency injection container,
so tools can simply add a parameter of type [IMcpServer] to their method signature to access it.
The parameters passed to [sendNotificationAsync] should be an instance of [ProgressNotificationParams], which includes the current progress, total steps, and an optional message.
[sendNotificationAsync]: https://modelcontextprotocol.github.io/csharp-sdk/api/ModelContextProtocol.McpEndpointExtensions.html#ModelContextProtocol_McpEndpointExtensions_SendNotificationAsync_ModelContextProtocol_IMcpEndpoint_System_String_System_Threading_CancellationToken_
[IMcpServer]: https://modelcontextprotocol.github.io/csharp-sdk/api/ModelContextProtocol.Server.IMcpServer.html
[ProgressNotificationParams]: https://modelcontextprotocol.github.io/csharp-sdk/api/ModelContextProtocol.Protocol.ProgressNotificationParams.html
The server must verify that the caller provided a `progressToken` in the request and include it in the call to [sendNotificationAsync]. The following example demonstrates how a server can send a progress notification:
[!code-csharp[](samples/server/Tools/LongRunningTools.cs?name=snippet_SendProgress)]
### Client Implementation
Clients request progress updates by including a `progressToken` in the parameters of a request.
Note that servers are not required to support progress tracking, so clients should not depend on receiving progress updates.
In the MCP C# SDK, clients can specify a `progressToken` in the request parameters when calling a tool method.
The client should also provide a notification handler to process "notifications/progress" notifications.
There are two way to do this. The first is to register a notification handler using the [RegisterNotificationHandler] method on the [IMcpClient] instance. A handler registered this way will receive all progress notifications sent by the server.
[IMcpClient]: https://modelcontextprotocol.github.io/csharp-sdk/api/ModelContextProtocol.Client.IMcpClient.html
[RegisterNotificationHandler]: https://modelcontextprotocol.github.io/csharp-sdk/api/ModelContextProtocol.IMcpEndpoint.html#ModelContextProtocol_IMcpEndpoint_RegisterNotificationHandler_System_String_System_Func_ModelContextProtocol_Protocol_JsonRpcNotification_System_Threading_CancellationToken_System_Threading_Tasks_ValueTask__
```csharp
mcpClient.RegisterNotificationHandler(NotificationMethods.ProgressNotification,
(notification, cancellationToken) =>
{
if (JsonSerializer.Deserialize<ProgressNotificationParams>(notification.Params) is { } pn &&
pn.ProgressToken == progressToken)
{
// progress.Report(pn.Progress);
Console.WriteLine($"Tool progress: {pn.Progress.Progress} of {pn.Progress.Total} - {pn.Progress.Message}");
}
return ValueTask.CompletedTask;
}).ConfigureAwait(false);
```
The second way is to pass a [Progress`<T>`] instance to the tool method. [Progress`<T>`] is a standard .NET type that provides a way to receive progress updates.
For the purposes of MCP progress notifications, `T` should be [ProgressNotificationValue].
The MCP C# SDK will automatically handle progress notifications and report them through the [Progress`<T>`] instance.
This notification handler will only receive progress updates for the specific request that was made,
rather than all progress notifications from the server.
[Progress`<T>`]: https://learn.microsoft.com/en-us/dotnet/api/system.progress-1
[ProgressNotificationValue]: https://modelcontextprotocol.github.io/csharp-sdk/api/ModelContextProtocol.ProgressNotificationValue.html
[!code-csharp[](samples/client/Program.cs?name=snippet_ProgressHandler)]

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using System.Text.Json;
using ModelContextProtocol;
using ModelContextProtocol.Client;
using ModelContextProtocol.Protocol;
var endpoint = Environment.GetEnvironmentVariable("ENDPOINT") ?? "http://localhost:3001";
var clientTransport = new SseClientTransport(new()
{
Endpoint = new Uri(endpoint),
TransportMode = HttpTransportMode.StreamableHttp,
});
McpClientOptions options = new()
{
ClientInfo = new()
{
Name = "ProgressClient",
Version = "1.0.0"
}
};
await using var mcpClient = await McpClientFactory.CreateAsync(clientTransport, options);
var tools = await mcpClient.ListToolsAsync();
foreach (var tool in tools)
{
Console.WriteLine($"Connected to server with tools: {tool.Name}");
}
Console.WriteLine($"Calling tool: {tools.First().Name}");
// <snippet_ProgressHandler>
var progressHandler = new Progress<ProgressNotificationValue>(value =>
{
Console.WriteLine($"Tool progress: {value.Progress} of {value.Total} - {value.Message}");
});
var result = await mcpClient.CallToolAsync(toolName: tools.First().Name, progress: progressHandler);
// </snippet_ProgressHandler>
foreach (var block in result.Content)
{
if (block is TextContentBlock textBlock)
{
Console.WriteLine(textBlock.Text);
}
else
{
Console.WriteLine($"Received unexpected result content of type {block.GetType()}");
}
}

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<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup>
<OutputType>Exe</OutputType>
<TargetFramework>net9.0</TargetFramework>
<ImplicitUsings>enable</ImplicitUsings>
<Nullable>enable</Nullable>
</PropertyGroup>
<ItemGroup>
<PackageReference Include="ModelContextProtocol.Core" Version="0.3.0-preview.3" />
</ItemGroup>
</Project>

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using Progress.Tools;
var builder = WebApplication.CreateBuilder(args);
// Add services to the container.
builder.Services.AddMcpServer()
.WithHttpTransport()
.WithTools<LongRunningTools>();
builder.Logging.AddConsole(options =>
{
options.LogToStandardErrorThreshold = LogLevel.Information;
});
var app = builder.Build();
app.UseHttpsRedirection();
app.MapMcp();
app.Run();

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<Project Sdk="Microsoft.NET.Sdk.Web">
<PropertyGroup>
<TargetFramework>net9.0</TargetFramework>
<Nullable>enable</Nullable>
<ImplicitUsings>enable</ImplicitUsings>
</PropertyGroup>
<ItemGroup>
<PackageReference Include="ModelContextProtocol.AspNetCore" Version="0.3.0-preview.3" />
</ItemGroup>
</Project>

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@HostAddress = http://localhost:3001
POST {{HostAddress}}/
Accept: application/json, text/event-stream
Content-Type: application/json
MCP-Protocol-Version: 2025-06-18
{
"jsonrpc": "2.0",
"id": 2,
"method": "tools/call",
"params": {
"_meta": {
"progressToken": "abc123"
},
"name": "long_running_tool"
}
}

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{
"$schema": "https://json.schemastore.org/launchsettings.json",
"profiles": {
"http": {
"commandName": "Project",
"dotnetRunMessages": true,
"launchBrowser": false,
"applicationUrl": "http://localhost:3001",
"environmentVariables": {
"ASPNETCORE_ENVIRONMENT": "Development"
}
},
"https": {
"commandName": "Project",
"dotnetRunMessages": true,
"launchBrowser": false,
"applicationUrl": "https://localhost:7175;http://localhost:3001",
"environmentVariables": {
"ASPNETCORE_ENVIRONMENT": "Development"
}
}
}
}

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using System.ComponentModel;
using ModelContextProtocol;
using ModelContextProtocol.Protocol;
using ModelContextProtocol.Server;
namespace Progress.Tools;
[McpServerToolType]
public class LongRunningTools
{
[McpServerTool, Description("Demonstrates a long running tool with progress updates")]
public static async Task<string> LongRunningTool(
IMcpServer server,
RequestContext<CallToolRequestParams> context,
int duration = 10,
int steps = 5)
{
var progressToken = context.Params?.ProgressToken;
var stepDuration = duration / steps;
for (int i = 1; i <= steps; i++)
{
await Task.Delay(stepDuration * 1000);
// <snippet_SendProgress >
if (progressToken is not null)
{
await server.SendNotificationAsync("notifications/progress", new ProgressNotificationParams
{
ProgressToken = progressToken.Value,
Progress = new ProgressNotificationValue
{
Progress = i,
Total = steps,
Message = $"Step {i} of {steps} completed.",
},
});
}
// </snippet_SendProgress >
}
return $"Long running tool completed. Duration: {duration} seconds. Steps: {steps}.";
}
}

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{
"Logging": {
"LogLevel": {
"Default": "Information",
"Microsoft.AspNetCore": "Warning"
}
}
}

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