How do I install the Gumcli skill?

Run npx skillmds@latest add vchelaru/gumcli in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

What does the Gumcli skill do?

gumcli It is listed under Coding & Dev Tools on SkillMD.

Is Gumcli safe to use?

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Gumcli?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Gumcli free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Gumcli?

vchelaru (@vchelaru) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Gumcli by vchelaru — Agent Skill

Name: Gumcli
Author: vchelaru

File contents

gumcli

gumcli is a cross-platform .NET tool for working with Gum projects without the editor. It is the primary way an AI assistant acts on a Gum project and verifies its own work: machine-readable output on stdout, meaningful exit codes, fully headless. Full reference: https://docs.flatredball.com/gum/cli.

Install

dotnet tool install -g GumCli

The edit → validate → verify loop

After any change to a Gum project (by hand, by tool, or by an assistant), run this loop. Skipping validation is the most common way agent-authored UI breaks silently.

1. Generate code (project + codegen mode only)

gumcli codegen-init  MyProject.gumx     # once: writes code-gen settings
gumcli codegen       MyProject.gumx     # after any element edit: emits typed C#

Regenerate after editing elements so the generated classes match the XML. If you rename or delete an element, delete its stale generated .cs file before regenerating.

2. Validate — always

gumcli check MyProject.gumx            # human-readable
gumcli check MyProject.gumx --json     # machine-readable

check catches the mistakes that are easy to make and invisible otherwise — most importantly misspelled XML element names that Gum drops without error (see gum-file-format). Exit code 0 = clean, 1 = errors found, 2 = project could not be loaded / bad arguments. Branch on the exit code; do not parse prose. Run check after every hand edit before trusting the file.

3. Verify visually

Compiling is not proof the UI looks right. Render it and inspect:

gumcli screenshot MyProject.gumx ScreenOrComponentName --output out.png
gumcli svg        MyProject.gumx ScreenOrComponentName --output out.svg

Open the image to confirm layout matches intent. With a multimodal model, the assistant can look at the PNG directly.

Other commands

Command	Purpose
`gumcli new <path> [--template forms\|empty]`	Scaffold a new project. `forms` (default) includes the built-in Forms controls.
`gumcli fonts <project.gumx>`	Generate missing bitmap font files (`.fnt`+`.png`). Windows-only.
`gumcli pack <project.gumx>`	Bundle a project into a single file.

Notes

stdout is data, stderr is chatter. Consume results (--json, paths) from stdout; banners and progress go to stderr.
Pair gumcli with the MCP documentation server so the assistant can look up a property while it drives the project. See https://docs.flatredball.com/gum/ai/gumcli-for-agents.

---name: gumclidescription: gumcli---# gumcli`gumcli` is a cross-platform .NET tool for working with Gum projects **without**the editor. It is the primary way an AI assistant acts on a Gum project andverifies its own work: machine-readable output on stdout, meaningful exit codes,fully headless. Full reference: <https://docs.flatredball.com/gum/cli>.## Install```dotnet tool install -g GumCli```## The edit → validate → verify loopAfter **any** change to a Gum project (by hand, by tool, or by an assistant),run this loop. Skipping validation is the most common way agent-authored UIbreaks silently.### 1. Generate code (project + codegen mode only)```gumcli codegen-init MyProject.gumx # once: writes code-gen settingsgumcli codegen MyProject.gumx # after any element edit: emits typed C#```Regenerate after editing elements so the generated classes match the XML. If yourename or delete an element, delete its stale generated `.cs` file beforeregenerating.### 2. Validate — always```gumcli check MyProject.gumx # human-readablegumcli check MyProject.gumx --json # machine-readable````check` catches the mistakes that are easy to make and invisible otherwise —most importantly **misspelled XML element names that Gum drops without error**(see **gum-file-format**). Exit code `0` = clean, `1` = errors found, `2` =project could not be loaded / bad arguments. Branch on the exit code; do notparse prose. Run `check` after every hand edit before trusting the file.### 3. Verify visuallyCompiling is not proof the UI looks right. Render it and inspect:```gumcli screenshot MyProject.gumx ScreenOrComponentName --output out.pnggumcli svg MyProject.gumx ScreenOrComponentName --output out.svg```Open the image to confirm layout matches intent. With a multimodal model, theassistant can look at the PNG directly.## Other commands| Command | Purpose ||---------|---------|| `gumcli new <path> [--template forms\|empty]` | Scaffold a new project. `forms` (default) includes the built-in Forms controls. || `gumcli fonts <project.gumx>` | Generate missing bitmap font files (`.fnt`+`.png`). **Windows-only.** || `gumcli pack <project.gumx>` | Bundle a project into a single file. |## Notes- **stdout is data, stderr is chatter.** Consume results (`--json`, paths) from stdout; banners and progress go to stderr.- Pair `gumcli` with the MCP documentation server so the assistant can look up a property while it drives the project. See <https://docs.flatredball.com/gum/ai/gumcli-for-agents>.

Frequently asked questions

Gumcli