ASP.NET Core Debugger — MCP Server for AI Agents

Name: ASP.NET Core Debugger — MCP Server for AI Agents
Author: magna-nz

by magna-nzversion 1.4.0i★ –iRuns on your computer

Registry nameio.github.magna-nz/aspnetcore-debugger-mcp

Install

Overview

Description from the maker (original English)

MCP server giving AI agents interactive .NET / ASP.NET Core debugging via netcoredbg + DAP.

PopNx MCP’s three pillars

These three are never merged into one score: opinions, measurements and popularity are different things.

User voiceiNo reviews yetReviews open together with accounts in a later step
Our basic checksi1 of 1 passedChecked from public information; code not scanned yet
UsageiNot measured yet★ –

What you can do with it

We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.

Connection: Runs on your computer
Transport: stdio
Category: Developer tools

Install

Pick the AI app you use, then copy the settings.

Before you install

Basic checks: 1 of 1 passed
Runs on your computer with your user’s permissions (files, network, apps).
The registry lists no key to fill in.

Which app do you use?

ClaudeClaude CodeCursorVS CodeChatGPT

Pick your app above. We remember it, so next time the button says “Install in …”.

Open Claude Desktop → Settings → Developer → Edit Config, and paste this into claude_desktop_config.json

{
  "mcpServers": {
    "aspnetcore-debugger": {
      "command": "dnx",
      "args": [
        "AspNetCoreDebuggerMcp",
        "--yes"
      ]
    }
  }
}

Run this in your terminal

claude mcp add aspnetcore-debugger -- dnx AspNetCoreDebuggerMcp --yes

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

{
  "mcpServers": {
    "aspnetcore-debugger": {
      "command": "dnx",
      "args": [
        "AspNetCoreDebuggerMcp",
        "--yes"
      ]
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "aspnetcore-debugger": {
      "type": "stdio",
      "command": "dnx",
      "args": [
        "AspNetCoreDebuggerMcp",
        "--yes"
      ]
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

This one runs on your computer, and ChatGPT can only connect to servers on the internet. Pick another app.

Your choice stays on this device in a cookie; no account needed.

These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

What it can do

Runs on your computer; the tool list appears in your AI app after you install it.

Basic checksi

We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 7, 2026

✓ Pass
Maker matches the repo
The registry name was verified with the GitHub account magna-nz, which owns the repo
… Not checked yet
Still maintained
We have not read this repo from GitHub yet
… Not checked yet
Has a licence
We have not read this repo from GitHub yet
– Not applicable
Endpoint responds
This one runs on your computer; there is no internet endpoint
– Not applicable
Sign-in with OAuth
Runs on your computer and uses local settings instead
… Not checked yet
No hidden instructions in tool descriptions
Runs on your computer; we can only read tool lists from internet endpoints

Compared with others in Developer toolsi

More stars than 0% of the other 4908 servers in this category
Published to the registry more recently than 41% of the other 4908 servers in this category
Basic checks equal to or better than 100% of the other 4908 servers in this category

Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.

Common questions

Is ASP.NET Core Debugger — MCP Server for AI Agents safe?

It passed 1 of 1 applicable basic checks. We have not read the code. Before adding a key or token, see what access the server asks for and use a key with only the permissions you need.

What keys or codes does it need?

The registry does not list a required key, though some servers ask you to sign in on first use.

Does it run on my computer or in the cloud?

It runs on your computer. Your AI app starts it when needed, and data does not pass through the maker’s servers (unless it calls an online service itself).

Is it still maintained?

The GitHub repo last changed –, and the latest version (1.4.0) reached the registry 2 months ago.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. You also need .NET on your computer.

What can I use instead?

In the same category: GitHub, Desktop Commander, Cloudflare MCP

Alternatives

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Reading a card:★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi

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GitHub’s official server lets AI read and manage code, issues and pull requests in your account. Use GitHub’s hosted version or run it locally with Docker.

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README from the maker

Open the README

Copied from the maker’s repo as written. PopNx MCP has not reviewed or endorsed it. HTML, images and scripts are removed. Links lead off this site.

ASP.NET Core Debugging MCP Server

The cross-platform .NET debugging MCP — runs on Linux, macOS, and Windows.

An MIT-licensed [MCP](https://modelcontextprotocol.io/) server that lets an AI agent (Claude, etc.) debug your .NET / ASP.NET Core app — netcoredbg bundled for every platform, nothing extra to install.

Instead of *"I think the bug is around line 42, try this"*, the agent runs your code, pauses it, reads the actual runtime values, mutates state to test a fix, and answers grounded in what it actually saw.

See it in action — 5 conversations showing the agent at work
How it works — architecture diagram
Use it in 3 steps — install + register with Claude
Platforms — supported OS / architecture matrix
Tools (27) — full tool surface grouped by purpose
How this compares — vs. other .NET / DAP MCPs
Docs — install, examples, tool reference, limits
License

See it in action

Why is my EF Core query returning empty?

You

GET /users/active returns [], but I know there are active users in the DB. What's the

query actually doing?

Claude

I'll pause inside UserRepository.GetActiveAsync and read what EF Core actually sent.

`sql

SELECT u.*

FROM Users AS u

WHERE u.IsActive = 1 AND u.TenantId = @__tenantId_0

@__tenantId_0 = 0

`

The SQL is correct; the parameter is wrong. TenantId = 0, but your tenants start at 1.

ICurrentUser.TenantId is being read in the repository constructor — before the request

scope resolves it. Fix: read the tenant inside the query (or apply it via HasQueryFilter

with IHttpContextAccessor) instead of capturing it at construction.

Why is my JWT auth returning 401?

You

/admin/users is 401-ing for Anna, but her token looks valid to me. What does the auth

handler actually see?

Claude

I'll break inside JwtBearerHandler.HandleAuthenticateAsync after her request lands.

`

Token signature: ✓ valid

Claims built:

name : anna

role : User

iss : https://auth.staging.example

aud : app-api

exp : 2026-05-26T14:12:00Z (not expired)

`

The token validates fine — but the claim is role=User. Your endpoint is

[Authorize(Roles="Admin")]. So the 401 is correct: Anna isn't actually an admin yet

upstream. Either her IdP record needs updating, or this policy is wrong.

Test a fix without restarting

You

I think capping discount at 100 fixes the bug. Test that hypothesis without me touching

the code.

Claude

I'll pause inside ApplyDiscount on the next checkout and mutate discount in place.

`

Paused at PricingService.cs:47

discount = 250 ← bug: two promos stacked

Set discount = 100, resumed.

Result:

subtotal = $400

final = $300

refund-service complaints: 0

`

Capping at 100 unblocks the flow downstream. Hypothesis confirmed — time to make the edit

for real and decide where the cap belongs (ApplyDiscount itself, or upstream in

PromoEngine).

My app is hung — what's actually blocking?

You

/reports hangs forever in staging. Attach and tell me why.

Claude

Attached. Ran hang_analyze.

`

Thread 12 (HTTP request)

→ blockedOnTask at ReportService.cs:38 Task.Wait() on T#14

Thread 14 (worker)

→ blockedOnMonitor at SqlConnectionPool.cs:91

waiting for SqlConnection

(pool max=5, in-use=5)

`

Classic sync-over-async deadlock. Thread 12 calls .Wait() on a task that itself needs to

open another SqlConnection from a fully-held pool. The connection it's holding can't be

released until the task completes; the task can't proceed until a connection frees up. Fix:

await all the way down in ReportService, or don't hold a connection across the awaited

call.

Where is a slow request actually spending its time?

You

GET /order/42 takes 800ms. I don't want to set breakpoints all over — just show me where

the time is going.

Claude

I'll auto-instrument your order pipeline and fire the request. Each entry logs the

timestamp + arguments, then resumes — the code runs near-normal speed.

`

[+ 4ms] → OrderController.GetOrder() id=42

[+ 6ms] --→ OrderService.LookupOrder() id=42

[+ 9ms] ----→ OrderRepository.FetchById() id=42

[+ 14ms] ------→ SqlClient.ExecuteQuery() sql="SELECT * FROM orders WHERE id=42"

[+ 287ms] ----→ EnrichmentService.Enrich() raw="rows(...)"

[+ 781ms] ------→ HttpClient.PostAsync() url="https://crm.internal/enrich"

`

Time is in the CRM enrichment HTTP call — 500ms inside HttpClient.PostAsync. DB itself

was 5ms. Worth caching EnrichmentService.Enrich or moving it off the request path.

More examples →

How it works

Claude (MCP client)

│ MCP (stdio / JSON-RPC) ▼ aspnetcore-debugger-mcp ← this server │ DAP (Debug Adapter Protocol) ▼ netcoredbg ← Samsung's MIT-licensed .NET debugger, child process │ ICorDebug ▼ target .NET process

A protocol bridge with agent-friendly composites on top — exception_autopsy, stack_explore, hang_analyze, and the trace tools — that bundle multiple DAP requests into a single tool call.

Use it in 3 steps

Install the tool — needs the .NET 10 SDK.

   dotnet tool install -g AspNetCoreDebuggerMcp --prerelease

The package bundles prebuilt netcoredbg for linux-x64, linux-arm64, win-x64, osx-x64, and osx-arm64 — no separate install needed.

Register with Claude — either the quick CLI command:

   claude mcp add aspnetcore-debugger -- aspnetcore-debugger-mcp

…or edit .mcp.json (project-scoped) / ~/.claude.json (global) / claude_desktop_config.json (Claude Desktop) directly:

"mcpServers": { "aspnetcore-debugger": { "command": "aspnetcore-debugger-mcp" } } }

3. **Just chat with Claude.** `/mcp` confirms it's connected. From there, describe what you want — *"why does this endpoint return null"* — and the agent picks the right tools.

Full install + troubleshooting →

Platforms

Bundled netcoredbg binary is selected at runtime — no per-platform install dance.

OS	Architectures	Status
Linux	x64, arm64	✅ Supported (Samsung prebuilt)
macOS	Intel (x64), Apple Silicon (arm64)	✅ Supported (arm64 built by us, since Samsung doesn't ship one)
Windows	x64	✅ Supported (Samsung prebuilt)

Requires the .NET 10 SDK on the host. The MCP server itself is a cross-platform .NET global tool — same install command everywhere.

Tools (27)

Category	Tools	What it's for
Session	`debug_launch`, `debug_attach`, `debug_disconnect`, `debug_state`	Start, attach to, or stop a debug session
Execution	`debug_continue`, `debug_pause`, `debug_step`, `breakpoint_wait`	Drive the debuggee and wait for it to stop
Breakpoints	`breakpoint_set`, `breakpoint_set_function`, `breakpoint_set_exception`, `breakpoint_set_data`, `breakpoint_remove`, `breakpoint_list`	Line, function, exception, and data breakpoints
Inspection	`threads_list`, `stacktrace_get`, `variables_get`, `variables_set`, `evaluate`, `stack_explore`	Examine and mutate program state
Exception Autopsy	`exception_autopsy`	One call: exception chain + top frames + locals + source snippet
Hang / Deadlock	`hang_analyze`	Auto-pause, classify each thread's blocking pattern (Monitor / Task / Semaphore / async / …)
Request Tracing	`trace_start`, `trace_get`, `trace_stop`	Server-side request tracing — auto-instrument a call chain and capture arguments at every entry
Process I/O	`process_read_output`	Drain the debuggee's stdout/stderr
Health	`debugger_health`	Quick check that netcoredbg loaded and the bundled binary is reachable

Full tool reference with parameters →

How this compares

Project	License	Platforms	Approach	.NET
aspnetcore-debugger-mcp (this)	MIT	Linux + macOS + Windows	netcoredbg via DAP, ASP.NET-focused composites (request tracing, hang analysis)	Native, .NET 10
debug-mcp	AGPL-3.0	Linux only (Win/macOS planned)	ICorDebug direct, Roslyn code nav	Native, .NET 10
mcp-debugger	—	Cross-platform	DAP	Via external debugger
dap-mcp	—	Cross-platform	DAP	Via external debugger
LLDB MCP	NCSA	Cross-platform	Native LLDB	No

Different sweet spots: this project is the MIT, cross-platform option, with ASP.NET-flavoured composites on top of a DAP. debug-mcp goes deeper into runtime internals via ICorDebug but is Linux-only and AGPL today.

Docs

[Install & configure](docs/install.md) — 3 steps, both Claude Code & Desktop, troubleshooting
[What you can do with it](docs/examples.md) — 7 things you can ask Claude to do for you
[Full tool reference](docs/tools.md) — every parameter on every tool
[Known limits](docs/limits.md) — when *not* to use this tool, adapter & tracing limits
[macOS Apple Silicon — building netcoredbg](docs/macos-arm64.md)
[Contributing](docs/contributing.md) — repo layout, tests, dev loop

License

MIT — see LICENSE. Built on netcoredbg (MIT) and the ModelContextProtocol SDK (MIT).

ASP.NET Core Debugger — MCP Server for AI Agents

Overview

PopNx MCP’s three pillars

What you can do with it

Install

Before you install

What it can do

Basic checksi

Maker matches the repo

Still maintained

Has a licence

Endpoint responds

Sign-in with OAuth

No hidden instructions in tool descriptions

Compared with others in Developer toolsi

Common questions

Alternatives

GitHub

Desktop Commander

Cloudflare MCP

README from the maker

ASP.NET Core Debugging MCP Server

The cross-platform .NET debugging MCP — runs on Linux, macOS, and Windows.

Contents

See it in action

Why is my EF Core query returning empty?

Why is my JWT auth returning 401?

Test a fix without restarting

My app is hung — what's actually blocking?

Where is a slow request actually spending its time?

How it works

Use it in 3 steps

Platforms

Tools (27)

How this compares

Docs

License