Show HN: no-fi – a linter for the ASCII wireframes agents draw

Wireframes without the distraction. no-fi is an agent skill that draws UI as plain text, so a team argues about layout, content, and flow instead of color and type.

Ask for a screen and Claude answers with a monospaced drawing: boxes, fields, buttons, tables, and bar charts made from plain characters. There are no colors, fonts, or icons to react to, so the only thing left to discuss is structure.

What it looks like

Install

Use it

The rules

The vocabulary

Examples

Check your work

Repository layout

What it looks like

╔══════════════════════════════════════╗ ║ SIGN IN ║ ║ ║ ║ ┌──────────────────────────────────┐ ║ ║ │ Email │ ║ ║ │ [ ana@acme.com_______________ ] │ ║ ║ │ │ ║ ║ │ Password │ ║ ║ │ [ ************_______________ ] │ ║ ║ │ │ ║ ║ │ [[ Sign in ]] [ Forgot? ] │ ║ ║ └──────────────────────────────────┘ ║ ╚══════════════════════════════════════╝

The outer frame is double-lined, every box inside it is single-lined, and the primary button gets double brackets. Larger screens are in Examples.

Pick one. Each puts the no-fi skill folder where your agent loads skills from.

Copy the install prompt from no-fi.dev and paste it into Claude Code or any agent. It runs the npx command below, or downloads the files one by one if it can't run npx.

npx no-fi-skill

This copies the skill into ~/.claude/skills/no-fi. Add --project to install it into ./.claude/skills/no-fi instead, and --force to replace an existing install.

npx skills add p-a-u-l-i-e/no-fi --skill no-fi

By hand

git clone https://github.com/p-a-u-l-i-e/no-fi.git cp -R no-fi/plugin/skills/no-fi ~/.claude/skills/

On claude.ai

Download no-fi.zip and upload it under Settings, Capabilities, Skills. It holds only the skill folder. GitHub's Download ZIP holds the whole repository, which claude.ai won't take as a skill.

The skill is plain text plus one small checker script, in Node and Python, so you can read every file before you install it.

Ask for a screen the way you would ask a designer for a sketch. Saying wireframe or sketch is enough to load the skill, or type /no-fi in Claude Code.

Wireframe a send-money form with three steps.

Draw the settings page for notification preferences.

Let's talk through the transactions table before we design it.

Claude replies with a fenced code block, runs the checker on it, and adds a note below the drawing for anything that needs a visual described in words.

Seven rules keep every wireframe readable. The full text is in SKILL.md.

44 elements in 7 groups: Structure, Fields, Buttons, Feedback, Navigation, Data, and Charts. Each element looks like the component it stands for:

The complete table, with a drawing and a note for each element, is in SKILL.md. The same data is in vocabulary.json.

Seven finished screens in examples/, built to use the whole vocabulary:

Your agent checks every wireframe before it shows you one. To check one yourself, from anywhere:

npx no-fi-skill check wireframe.txt

The checker also ships with the skill, in Node and Python with the same output. From an install, or from this repository:

node ~/.claude/skills/no-fi/scripts/check_wireframe.mjs wireframe.txt python3 plugin/skills/no-fi/scripts/check_wireframe.py wireframe.txt

It fails on unsupported characters, tabs, ASCII box borders, boxes that don't close or line up, mixed double and single lines in one box, a double-line box nested inside another box, table dividers that don't land in the same column, progress bars whose fill disagrees with their percentage, bar chart rows whose length disagrees with their value, heatmaps and stacked columns without a legend, and column charts that don't say what a row is worth.

plugin/skills/no-fi/vocabulary.json is the source of truth. These scripts live in scripts/, outside the skill, so they don't ship to users. After editing the vocabulary, run:

python3 scripts/sync_vocabulary.py # rewrite the tables in SKILL.md node scripts/check_coverage.mjs # every element appears in an example node plugin/skills/no-fi/scripts/check_wireframe.mjs plugin/skills/no-fi/examples/*.txt

python3 scripts/check_coverage.py gives the same coverage output without Node.

plugin/ the Claude plugin .claude-plugin/ plugin.json skills/no-fi/ the skill SKILL.md rules and vocabulary tables vocabulary.json the element vocabulary as data examples/ finished example screens scripts/ the wireframe checker scripts/ maintainer scripts: vocabulary sync and coverage bin/no-fi-skill.mjs the npx no-fi-skill command assets/ README images site/ the no-fi.dev site

License

MIT