# Uno DevServer

Builds, tests and maintains the Uno DevServer CLI, host and MCP proxy.

- Repository: https://github.com/unoplatform/uno (10099 stars)
- Category: Engineering
- License: Apache-2.0
- Last updated: 2026-11-01
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add unoplatform/uno --skill devserver -g -a claude-code -y`
Codex: `npx skills add unoplatform/uno --skill devserver -g -a codex -y`
Cursor: `npx skills add unoplatform/uno --skill devserver -g -a cursor -y`
Gemini CLI: `npx skills add unoplatform/uno --skill devserver -g -a gemini-cli -y`

## Description

Build, test, and maintain the Uno DevServer (CLI tool, RemoteControl Host, MCP proxy, add-in discovery). Use when working under src/Uno.UI.DevServer.Cli, src/Uno.UI.RemoteControl.Host, or src/Uno.UI.RemoteControl.DevServer.Tests, or on DevServer CLI commands, the MCP proxy, IDE channel, or add-in resolution.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# DevServer (CLI / Host / MCP)

Maintain and extend the Uno DevServer: the CLI tool, the Host process, MCP proxy integration, and add-in discovery. The DevServer projects are **independent of the UI framework** and do **not** require `crosstargeting_override.props`.

## 1. Architecture, a 2-process chain

1. **CLI** (`Uno.UI.DevServer.Cli`), entry point, user-facing commands, MCP STDIO proxy, start-lifecycle management.
2. **Host** (`Uno.UI.RemoteControl.Host`), ASP.NET Core server for Hot Reload, IDE channel, processors.

The CLI `start` command handles existing-server detection (AmbientRegistry), IDE channel rebinding, port allocation, and launches the Host in **direct mode** (no `--command`), so all arguments (including `--ideChannel`) reach the Host via `IConfiguration` regardless of Host binary version. Non-start commands (`stop`, `list`, `cleanup`) use the Host's controller mode (`--command=<verb>`). The CLI can also run in **MCP mode** (`--mcp-app`) as a Model Context Protocol proxy between AI agents and the running Host.

### Packages
| NuGet Package | Contents |
|---------------|----------|
| `Uno.DevServer` | CLI tool (installed via `dotnet tool`) |
| `Uno.WinUI.DevServer` | Host binaries, processors, BuildTransitive targets |

## 2. Source map
| Directory | Purpose |
|-----------|---------|
| `src/Uno.UI.DevServer.Cli/` | CLI tool: commands, helpers, MCP proxy |
| `src/Uno.UI.DevServer.Cli/Helpers/` | Discovery, caching, process helpers |
| `src/Uno.UI.DevServer.Cli/Mcp/` | MCP server, client proxy |
| `src/Uno.UI.RemoteControl.Host/` | Host process: server, extensibility, IDE channel |
| `src/Uno.UI.RemoteControl.Host/Extensibility/` | Add-in loading and discovery |
| `src/Uno.UI.RemoteControl.DevServer.Tests/` | Unit and integration tests |
| `build/test-scripts/` | PowerShell integration test harness |
| `build/nuget/Uno.WinUI.DevServer.nuspec` | NuGet package definition |

The rest: https://github.com/unoplatform/uno/blob/HEAD/.claude/skills/devserver/SKILL.md