MCPServer

MCPServer is a .NET 10 workspace for an MCP host, SSH tooling, AgentRouter, and a NativeAOT Python bridge.

The host runs stdio by default. Streamable HTTP is loopback-only and opt-in.

Protocol baseline: MCP 2025-11-25. The current implementation matrix lives in docs/SPEC_COMPLIANCE.md.

Workspace map

• MCPServer.Host is the primary MCP server host.
• MCPServer.Host.Sidecar is the sidecar entry point for host composition.
• MCPServer.Client.Console is the local client for stdio and HTTP checks.
• MCPServer.AgentRouter.* contains the AgentRouter contracts, application layer, infrastructure, and hosting composition.
• MCPServer.Ssh and MCPServer.Tools.Ssh own SSH policy, runtime, and MCP tool exposure.
• python/ contains the ctypes wrapper for the NativeAOT bridge.
• scripts/Sync-PythonBridge.ps1 publishes the native bridge, syncs the Python package payload, and can build the wheel.

Architecture at a glance

Solid arrows point from the owning project or boundary to the dependency it uses.

flowchart LR
    subgraph ClientSide["Client side"]
        Console["MCPServer.Client.Console"]
        ClientLib["MCPServer.Client"]
        ClientInfra["MCPServer.Client.Infrastructure"]
        Python["python/"]
        Native["MCPServer.AgentRouter.PythonBridge.Native"]
    end

    subgraph HostSide["Host side"]
        MainHost["MCPServer.Host"]
        Sidecar["MCPServer.Host.Sidecar"]
        Infra["MCPServer.Infrastructure"]
        App["MCPServer.Application"]
        Ssh["MCPServer.Ssh"]
        SshTools["MCPServer.Tools.Ssh"]
    end

    subgraph RouterCore["AgentRouter core"]
        ARAbs["Abstractions"]
        ARDom["Domain"]
        ARApp["Application"]
        ARInfra["Infrastructure"]
        ARHost["Hosting"]
    end

    Console --> ClientLib
    Console --> ClientInfra
    ClientInfra --> ClientLib

    Python --> Native
    Native --> ARApp

    MainHost --> Infra
    MainHost --> App
    Sidecar --> Ssh
    Infra --> App
    SshTools --> Ssh

    ARHost --> ARInfra --> ARApp --> ARDom --> ARAbs

Loading

Build and test

dotnet restore .\MCPServer.slnx
dotnet build .\MCPServer.slnx -c Debug
dotnet test .\MCPServer.slnx -c Debug

Run the host

Stdio host:

dotnet run --project .\MCPServer.Host\MCPServer.Host.csproj

Console against stdio:

dotnet run --project .\MCPServer.Client.Console\MCPServer.Client.Console.csproj -- --server-path dotnet --server-arg MCPServer.Host.dll --working-directory .\MCPServer.Host\bin\Debug\net10.0 --tool server.info

HTTP host on loopback:

$env:McpTransport__Http__Enabled = 'true'
$env:McpTransport__Http__Port = '3011'
dotnet run --project .\MCPServer.Host\MCPServer.Host.csproj

Console against HTTP:

dotnet run --project .\MCPServer.Client.Console\MCPServer.Client.Console.csproj -- --endpoint http://127.0.0.1:3011/mcp/ --tool ssh.profiles.list

Python bridge

The NativeAOT bridge ships separately.

The release and install path starts from .NET, then syncs the native payload into the Python package and builds the wheel. See docs/INSTALL.md.

If you only need the wrapper package layout, see python/README.md.

Read next

• docs/REPO_ARCHITECTURE.md
• docs/BUILD_AND_TEST.md
• docs/INSTALL.md
• docs/SSH_BOUNDARY.md
• docs/AGENT_ROUTER_BOUNDARY.md
• docs/SPEC_COMPLIANCE.md
• docs/KNOWN_DRIFT.md

Repository rules

• System.Text.Json only.
• Autofac for composition.
• No MediatR.
• Keep boundaries explicit.
• Fix the first real failure before chasing downstream metadata errors.