Install Universal Modder in VS Code / Copilot

Quick install

In VS Code Settings, enable chat.plugins.enabled. Run Chat: Install Plugin From Source in the Command Palette, then paste this repository URL:

https://github.com/rehan-remade/universal-modder

Paste the URL into the plugin installer, not into the ordinary terminal.

Before you start

Use a current VS Code installation with Copilot signed in and agent chat available. If you have not connected an account, follow Microsoft's Copilot setup. Account entitlements and model usage belong to your Copilot plan; installing this MIT-licensed toolkit does not provide a model subscription.

Prepare Git and Python 3.10 or later in the environment where agent commands will run. The Universal Modder requirements explain the optional tools for videos and 3D assets. A remote workspace or WSL terminal has its own installed tools and environment; check there if that is where you plan to work.

Before choosing a game, decide where to keep your mod source and notes. A dedicated development folder makes it easier to inspect file changes and separate a build project from the installed game's files. The first-mod tutorial starts with a small Terraria feature and a backup plan.

Step-by-step install

Step 1: Enable plugins in the intended workspace

Search Settings for chat.plugins.enabled and enable it. If the setting or installation command is unavailable, check your VS Code version and whether your organization manages AI features. A managed policy can require help from an administrator.

Open the project folder you intend to use for modding. Keep the account, workspace and terminal visible so that later checks refer to the same environment.

Step 2: Install from the GitHub repository

Run Chat: Install Plugin From Source, enter the URL above and review the identified source before completing installation. If the command palette flow differs in your VS Code version, follow Microsoft's agent plugin guide.

The repository's root plugin.json declares the Agent Plugins 1.0 schema. VS Code recognizes that format and discovers skills/ and the root mcp.json. The .claude-plugin/plugin.json file serves another supported format; this source installation uses the root manifest. Avoid a second manual copy of the skills while checking which source is active.

Step 3: Check skill discovery

Start a fresh agent chat. Use Chat: Configure Skills to inspect the available skills, then ask the agent to load mod-any-game and report its source. The relevant file in the repository is skills/mod-any-game/SKILL.md; it describes the investigation, planning and build loop.

For a clone-based workspace, the repository also contains .agents/skills, AGENTS.md and .vscode/mcp.json. Those files are useful when diagnosing discovery, but the source-install route does not require copying the entire repository into your mod project.

A useful first check is read-only:

Find and load Universal Modder's mod-any-game skill.
Report the skill source and summarize its first investigation steps.
Do not edit the game, install a loader or generate assets yet.

Check the reported path and instructions against skills/mod-any-game/SKILL.md in the repository. Continue only after you can identify the intended skill.

Step 4: Choose whether to use fal

For Install Plugin From Source, the plugin's root mcp.json supplies the fal server at https://mcp.fal.ai/mcp, with a bearer header using FAL_KEY.

For an opened repository clone, .vscode/mcp.json provides the workspace server and references the process variable as ${env:FAL_KEY}. A source-installed plugin does not require this workspace file to be copied into your mod project. Inspect the server's origin so you change the configuration belonging to your route.

Run MCP: List Servers to inspect fal and its source. A key is optional when using placeholder or original art; leave the server disabled if you are postponing generation. When enabling it, make the key available through the corresponding local environment or protected settings and inspect its status. Use VS Code's MCP management controls to manage the server and open its output log.

An integrated terminal can have a different environment from the VS Code process that launches an MCP server. If fal cannot authenticate, verify where the key was set before repeatedly restarting tools. The fal key troubleshooting guide separates CLI key checks from agent-server setup.

Step 5: Check the um CLI

Open VS Code's integrated terminal in your project and run:

um --help
um --version

You should see Universal Modder's command groups and an actual version. If the shell cannot find it, use the standalone CLI installation, reopen the terminal and repeat the checks. The um CLI reference explains the available commands and their help output.

Repeat the help check through the agent's terminal tool if it runs in another environment. A visible skill supplies instructions; the CLI check confirms that the commands those instructions use can actually start.

Check that it works

This is a setup checklist. The mod itself still needs a build and a check inside the game, which the Universal Modder tutorial covers separately.

Your first prompt

Try a small project with an observable result:

Use Universal Modder to plan one new Terraria weapon for my own game.
First inspect the installed edition, tModLoader version and save locations.
Read relevant knowledge-base notes and explain which apply to this setup.
Use placeholder art, propose the smallest working change, and write
MODDING_PLAN.md with build checks and the rollback steps.

This prompt scales the Terraria idea down to one weapon. The FalArsenal example shows the finished project's weapons and art pipeline; your first attempt does not need its full scope. More Universal Modder prompts are organized by task.

Common errors in VS Code / Copilot

• The install command is missing: inspect the plugin setting, your VS Code version and organization policy. Start with agent plugin discovery checks.
• The plugin is installed but its skill is absent: inspect its enabled state and skill source, then start a new conversation in the intended workspace. Check for an older manual copy before changing configuration.
• Git cannot start: run git --version in the affected environment. If the actual message is spawn git ENOENT, use the Git and working-directory checks.
• The agent cannot run um: use um command not found diagnosis in its terminal environment.
• fal reports an error: open the server's output log and identify whether the problem is authentication, connectivity or a disabled server. Preserve the exact message locally, keeping credentials out of shared reports.

Uninstall

Open Agent Plugins - Installed, find Universal Modder, and use its Uninstall action. Manage the installation through the interface you used to add it. If the entry is not listed, follow Microsoft's plugin removal instructions.

Start a new chat and confirm that the removed source no longer provides its skills. Workspace or user-level copies from another installation can remain. Preserve your mod source, notes and game backups. If you installed um independently, remove it through its separate tool-manager uninstall.

Other agents

Compare Claude Code, Codex, Cursor, Gemini CLI and OpenCode. The installation overview keeps their quick commands together.