Agents Plugins

🕹️ Agents Plugins

The CS Modding marketplace (csmodding) of agent plugins for Claude Code and OpenAI Codex CLI.

Give your coding agent eyes and hands inside a running game: its HTML UI, and its C#/ECS internals. Generic tooling, developed and verified against Cities: Skylines II.

[](https://github.com/CitiesSkylinesModding/agents-plugins/actions/workflows/ci.yml) [](https://www.npmjs.com/package/@csmodding/gameface-devtools-mcp) [](LICENSE)

[Plugins](#plugins) · [Install](#install) · [Development](#development)

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Plugins

| Plugin | Give your agent… | Runs on | Docs | | --------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | 🖼️ [coherent-gameface](plugins/coherent-gameface/README.md) | Eyes and hands in any Coherent Gameface (Cohtml) game UI over CDP: evaluate JS, screenshot, drive the DOM, console, JS breakpoints. Plus an engine skill and a driving skill. | Node 22.4+ | [README](plugins/coherent-gameface/README.md) · [Tools reference](plugins/coherent-gameface/mcp/README.md) · npm | | 🔬 [unity-devtools](plugins/unity-devtools/README.md) | A live line into a Unity Mono dev build over the Mono Soft Debugger: reflect types, invoke C#, read & write ECS state. No code injection. Plus a driving skill. | .NET 10 (Windows) | [README](plugins/unity-devtools/README.md) · [Tools reference](plugins/unity-devtools/README.md#tools) |

Both plugins are generic: they target any game or application embedding the technology, with Cities: Skylines II as the reference target where everything is field-verified.

> [!TIP] > Not using Claude Code or Codex CLI? The Gameface MCP server is also published on npm as > @csmodding/gameface-devtools-mcp > and works with any MCP client (Cursor, Gemini CLI, VS Code, …).

Install

Add the marketplace once, then install the plugin(s) you want. Each plugin autoloads its MCP server from a committed artifact: no installation step, works offline, version-locked to the plugin.

Claude Code

/plugin marketplace add CitiesSkylinesModding/agents-plugins
/plugin install coherent-gameface@csmodding
/plugin install unity-devtools@csmodding

Or from your terminal, claude plugin marketplace add … / claude plugin install … with the same arguments.

Codex CLI

codex plugin marketplace add CitiesSkylinesModding/agents-plugins
codex plugin add coherent-gameface@csmodding
codex plugin add unity-devtools@csmodding

Then run /mcp to confirm the servers connected. Each plugin's README covers its requirements, configuration and troubleshooting.

Development

Uses mise + bun (never npx). The repository is a marketplace: plugin sources live under plugins//, and everything a plugin ships lives inside its directory. The root is a bun workspace carrying the lint/format tooling (oxlint, oxfmt) and the lefthook git hooks; the Gameface MCP server is the plugins/coherent-gameface/mcp/ workspace package, and the Unity MCP server is a .NET solution (agents-plugins.slnx).

bun install         # install all workspace deps (also installs the git hooks)
mise check          # verify (read-only): type-check, lint, format
mise fix            # auto-fix lint + format in place
mise build          # rebuild every shipped artifact (commit the results)

Run mise tasks for the full list, and see [AGENTS.md](AGENTS.md) (plus each plugin's own AGENTS.md) for the architecture notes.

Source & license

This open-source MCP server is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: CitiesSkylinesModding
• Source: CitiesSkylinesModding/agents-plugins
• License: MIT

Install and usage instructions live in the source repository linked above.