CSharpEssentials.LoggerHelper.MCP 5.2.2

CSharpEssentials.LoggerHelper.MCP

Give your AI assistant eyes — and hands — on your logs.

CSharpEssentials.LoggerHelper.MCP adds a zero-dependency Model Context Protocol (MCP) server to any ASP.NET Core application that uses LoggerHelper. Point Claude Desktop, Claude Code, Cursor, or any MCP-compatible client at /mcp and ask in plain English:

• "Are all sinks healthy?"
• "Search logs for payment failures in the last 5 minutes"
• "Set Console to Error and Fatal only — no restart needed"
• "Disable the Email sink during tonight's maintenance window"

No dashboard to stand up. No extra infrastructure. One POST endpoint, 7 tools, zero external dependencies.

Install

dotnet add package CSharpEssentials.LoggerHelper.MCP

Requires: CSharpEssentials.LoggerHelper ≥ 5.2.0

Wire up (Program.cs)

using CSharpEssentials.LoggerHelper;
using CSharpEssentials.LoggerHelper.MCP;

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddLoggerHelper(builder.Configuration);
builder.Services.AddLoggerHelperMcp();   // register MCP tools in DI

var app = builder.Build();
app.UseLoggerHelper();
app.MapLoggerHelperMcp("/mcp");          // expose POST /mcp (JSON-RPC 2.0)

app.Run();

Available MCP Tools — 7 total

Read-only (4 tools)

Action tools — new in v5.2.0 (3 tools)

loggerhelper_search_logs requires contextual logging enabled in your config:

"General": { "EnableContextualLogging": true, "ContextualBufferCapacity": 200 }

Connect to Claude Desktop

Add to claude_desktop_config.json:

• Mac: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "myapp-logger": {
      "url": "http://localhost:5000/mcp",
      "transport": "streamable-http"
    }
  }
}

Restart Claude Desktop. A 🔌 icon will appear showing the connected tools.

Connect to Claude Code (CLI)

# IMPORTANT: always specify --transport http
claude mcp add --transport http myapp-logger http://localhost:5000/mcp

⚠️ Without --transport http, Claude Code defaults to stdio (local process) and the connection will fail with × failed. The --transport flag is mandatory for HTTP servers.

Verify the connection:

claude mcp list
# Expected output:
# > myapp-logger · ✓ connected   (7 tools)

How to query tools — natural language, not commands

/mcp in Claude Code is a discovery command — it shows tool metadata but does not call anything.

To actually get data from your app, ask in plain English in the chat:

What happens under the hood:

You type:  "Are there any errors?"
     ↓
Claude understands intent → picks loggerhelper_get_errors
     ↓
POST /mcp  {"method":"tools/call","params":{"name":"loggerhelper_get_errors","arguments":{"count":10}}}
     ↓
Your app returns:  { "errors": [...] }
     ↓
Claude responds in natural language with real data from your app

Connect to Cursor

In Cursor settings → MCP section, add:

{
  "mcpServers": {
    "myapp-logger": {
      "url": "http://localhost:5000/mcp",
      "transport": "http"
    }
  }
}

Test without an AI client (curl)

# List all 7 available tools
curl -X POST http://localhost:5000/mcp \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/list","params":{}}'

# Get health status
curl -X POST http://localhost:5000/mcp \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"loggerhelper_get_health","arguments":{}}}'

# Get last 5 errors
curl -X POST http://localhost:5000/mcp \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":3,"method":"tools/call","params":{"name":"loggerhelper_get_errors","arguments":{"count":5}}}'

# Search logs for a keyword
curl -X POST http://localhost:5000/mcp \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":4,"method":"tools/call","params":{"name":"loggerhelper_search_logs","arguments":{"query":"payment","count":20}}}'

# Change Console to Error+Fatal only (runtime, no restart)
curl -X POST http://localhost:5000/mcp \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":5,"method":"tools/call","params":{"name":"loggerhelper_set_log_level","arguments":{"sink":"Console","levels":"Error,Fatal"}}}'

# Toggle a sink off
curl -X POST http://localhost:5000/mcp \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":6,"method":"tools/call","params":{"name":"loggerhelper_toggle_sink","arguments":{"sink":"Email","enabled":false}}}'

PowerShell equivalent:

curl http://localhost:5000/mcp `
  -Method POST `
  -ContentType "application/json" `
  -Body '{"jsonrpc":"2.0","id":1,"method":"tools/list","params":{}}'

Troubleshooting

× failed after claude mcp add

The most common causes:

Remove a misconfigured server

claude mcp remove myapp-logger

Verify the endpoint is reachable before connecting Claude

curl http://localhost:5000/mcp \
  -X POST -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/list","params":{}}'

If you get a JSON response with "tools":[...] the server is healthy. If Connection refused, the app is not running on that port.

AI client compatibility

Transport details

Implements the Streamable HTTP transport (MCP spec 2024-11-05):

• POST /mcp → JSON-RPC 2.0 request/response
• Supported methods: initialize, tools/list, tools/call
• Zero external dependencies — pure System.Text.Json + Microsoft.AspNetCore.App

Why this matters

Serilog and NLog have no built-in AI tooling. With LoggerHelper MCP:

• AI assistants can diagnose logging issues without reading log files
• AI assistants can act — change levels, toggle sinks — not just observe
• Zero additional infrastructure (no Seq, no Kibana, no Grafana)
• Works in production with RequireAuthorization protecting the endpoint
• Runtime changes survive without restart; original config restored on restart

Docs

• loggerhelper.com
• GitHub
• Full Changelog