Skills mcp-csharp-publish

Name: mcp-csharp-publish
Author: dotnet

install

source · Clone the upstream repo

git clone https://github.com/dotnet/skills

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/dotnet/skills "$T" && mkdir -p ~/.claude/skills && cp -r "$T/plugins/dotnet-ai/skills/mcp-csharp-publish" ~/.claude/skills/dotnet-skills-mcp-csharp-publish && rm -rf "$T"

manifest: plugins/dotnet-ai/skills/mcp-csharp-publish/SKILL.md

source content

C# MCP Server Publishing

Publish and deploy MCP servers to their target platforms. stdio servers are distributed as NuGet tool packages. HTTP servers are containerized and deployed to Azure or other container hosts. Both can optionally be listed in the official MCP Registry.

When to Use

Packaging a stdio MCP server for NuGet distribution
Creating a Docker container for an HTTP MCP server
Deploying to Azure Container Apps or App Service
Publishing to the official MCP Registry for discoverability
Setting up
```
server.json
```
metadata for the MCP Registry

Stop Signals

Server not tested yet? → Use
```
mcp-csharp-test
```
first
Server not working locally? → Use
```
mcp-csharp-debug
```
No server project yet? → Use
```
mcp-csharp-create
```
Publishing a non-MCP NuGet package? → Use
```
nuget-trusted-publishing
```
instead

Inputs

Input	Required	Description
Transport type	Yes	`stdio` → NuGet path, `http` → Docker/Azure path
Target destination	Yes	NuGet.org, Docker registry, Azure Container Apps, Azure App Service, MCP Registry
Project path	Yes	Path to the `.csproj` file
Package ID / server name	Required for publishing	NuGet `PackageId` or MCP Registry name

Workflow

Step 1: Choose the publishing path

Transport	Primary Destination	Users Run With
stdio	NuGet.org	`dnx YourPackage@version`
HTTP	Docker → Azure	Container URL

Both paths can optionally publish to the MCP Registry for discoverability.

Step 2a: NuGet publishing (stdio servers)

Configure
.csproj
with package properties:

<PropertyGroup>
  <PackAsTool>true</PackAsTool>
  <ToolCommandName>mymcpserver</ToolCommandName>
  <PackageId>YourUsername.MyMcpServer</PackageId>
  <Version>1.0.0</Version>
  <Authors>Your Name</Authors>
  <Description>MCP server for interacting with MyService</Description>
  <PackageLicenseExpression>MIT</PackageLicenseExpression>
  <PackageTags>mcp;modelcontextprotocol;ai;llm</PackageTags>
  <PackageReadmeFile>README.md</PackageReadmeFile>
</PropertyGroup>

<ItemGroup>
  <None Include="README.md" Pack="true" PackagePath="\" />
</ItemGroup>

Build and pack:

dotnet build -c Release
dotnet pack -c Release

Test locally before publishing:

dotnet tool install --global --add-source bin/Release/ YourUsername.MyMcpServer
mymcpserver --help          # verify it runs
dotnet tool uninstall --global YourUsername.MyMcpServer

Push to NuGet.org:

dotnet nuget push bin/Release/*.nupkg \
  --api-key YOUR_NUGET_API_KEY \
  --source https://api.nuget.org/v3/index.json

Verify — users configure in
```
mcp.json
```
:

{
  "servers": {
    "MyMcpServer": {
      "type": "stdio",
      "command": "dnx",
      "args": ["YourUsername.MyMcpServer@1.0.0", "--yes"]
    }
  }
}

For detailed NuGet packaging and trusted publishing setup, see references/nuget-packaging.md.

Step 2b: Docker containerization (HTTP servers)

Create Dockerfile:

FROM mcr.microsoft.com/dotnet/sdk:10.0 AS build
WORKDIR /src
COPY *.csproj ./
RUN dotnet restore
COPY . ./
RUN dotnet publish -c Release -o /app

FROM mcr.microsoft.com/dotnet/aspnet:10.0
WORKDIR /app
COPY --from=build /app .

# Non-root user for security
RUN adduser --disabled-password --gecos '' appuser
USER appuser

ENV ASPNETCORE_URLS=http://+:8080
EXPOSE 8080
HEALTHCHECK --interval=30s --timeout=3s --start-period=10s --retries=3 \
  CMD curl -f http://localhost:8080/health || exit 1
ENTRYPOINT ["dotnet", "MyMcpServer.dll"]

Build and test locally:

docker build -t mymcpserver:latest .
docker run -d -p 3001:8080 -e API_KEY=test-key --name mymcpserver mymcpserver:latest
curl http://localhost:3001/health

Push to container registry:

# Docker Hub
docker tag mymcpserver:latest <yourusername>/<mymcpserver>:1.0.0
docker push <yourusername>/<mymcpserver>:1.0.0

# Azure Container Registry
az acr login --name yourregistry
docker tag mymcpserver:latest <yourregistry>.azurecr.io/<mymcpserver>:1.0.0
docker push <yourregistry>.azurecr.io/<mymcpserver>:1.0.0

Step 3: Deploy to Azure (HTTP servers)

Azure Container Apps (recommended — serverless with auto-scaling):

az containerapp create \
  --name mymcpserver \
  --resource-group mygroup \
  --environment myenvironment \
  --image <yourregistry>.azurecr.io/<mymcpserver>:1.0.0 \
  --target-port 8080 \
  --ingress external \
  --min-replicas 0 \
  --max-replicas 10 \
  --secrets api-key=my-actual-api-key \
  --env-vars API_KEY=secretref:api-key

Azure App Service (traditional web hosting):

az webapp create \
  --name mymcpserver \
  --resource-group mygroup \
  --plan myplan \
  --deployment-container-image-name <yourregistry>.azurecr.io/<mymcpserver>:1.0.0

For detailed Azure deployment, see references/docker-azure.md.

Step 4: Publish to MCP Registry (optional)

List your server in the official MCP Registry for discoverability.

Install
mcp-publisher
:

# macOS/Linux
brew install mcp-publisher

# Or download from https://github.com/modelcontextprotocol/registry/releases

Create
.mcp/server.json
(or run
```
mcp-publisher init
```
to generate interactively):

{
  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-12-11/server.schema.json",
  "name": "io.github.username/servername",
  "description": "Your server description",
  "version": "1.0.0",
  "packages": [{
    "registryType": "nuget",
    "registryBaseUrl": "https://api.nuget.org",
    "identifier": "YourUsername.MyMcpServer",
    "version": "1.0.0",
    "transport": { "type": "stdio" }
  }],
  "repository": {
    "url": "https://github.com/username/repo",
    "source": "github"
  }
}

Version consistency (critical): The root
version
,
packages[].version
, and
<Version>
in
.csproj
must all match. A mismatch causes registry validation failures or users downloading the wrong version.

Authenticate and publish:

mcp-publisher login github      # name must be io.github.<username>/... for GitHub auth
mcp-publisher publish

Verify:

curl "https://registry.modelcontextprotocol.io/v0.1/servers?search=io.github.<username>/<servername>"

For Registry details (namespace conventions, environment variables, CI/CD automation), see references/mcp-registry.md.

Step 5: Security checklist

No hardcoded secrets — use environment variables or Key Vault
HTTPS enabled for HTTP transport in production
Health check endpoint implemented
Input validation on all tool parameters
Rate limiting considered for HTTP servers

Validation

NuGet: Package installs and runs via
```
dnx PackageId@version
```
Docker: Container starts and health check passes
Azure: Server is reachable and tools respond
MCP Registry: Server appears at
```
registry.modelcontextprotocol.io
```
MCP client can connect and call tools on the deployed server

Common Pitfalls

Pitfall	Solution
NuGet package doesn't run as a tool	Missing `<PackAsTool>true</PackAsTool>` in `.csproj`
Version mismatch between `.csproj` and `server.json`	Keep `<Version>` , `server.json` root `version` , and `packages[].version` in sync
Docker container exits immediately	Check entrypoint DLL name matches project output. Run `docker logs mymcpserver` for errors
Azure Container App returns 502	Target port mismatch. Ensure `--target-port` matches `ASPNETCORE_URLS` port in the container
MCP Registry rejects publish	Name must follow namespace convention: `io.github.<username>/<name>` for GitHub auth
API keys leaked in Docker image	Use multi-stage builds. Never `COPY` `.env` files. Pass secrets via `--env-vars` at runtime

Related Skills

```
mcp-csharp-create
```
— Create a new MCP server project
```
mcp-csharp-debug
```
— Running and interactive debugging
```
mcp-csharp-test
```
— Automated tests and evaluations

Reference Files

references/nuget-packaging.md — Complete NuGet
```
.csproj
```
configuration,
```
server.json
```
for MCP, NuGet.org push, testing with
```
dnx
```
, version management. Load when: publishing a stdio server to NuGet.
references/docker-azure.md — Production Dockerfile patterns, ACR setup, Azure Container Apps full configuration, App Service with Key Vault, secrets management. Load when: deploying an HTTP server to Docker or Azure.
references/mcp-registry.md —
```
mcp-publisher
```
CLI installation,
```
server.json
```
schema, namespace conventions (GitHub vs DNS auth), CI/CD automation. Load when: publishing to the official MCP Registry.

More Info

NuGet publishing — NuGet.org publishing guide
Azure Container Apps — Serverless container hosting
MCP Registry — Official MCP server registry