one-shot-ui AGENTS.md

one-shot-ui AGENTS.md is an instructions file for Codex, OpenCode from TN0123/one-shot-ui. It costs 2,425 tokens per session, scanned A, original, MIT.

A command-line tool for measuring a user interface from a reference screenshot and comparing it with your implementation. It reports layout, colors, spacing, and text measurements so you can copy the design's style into code.

In plain words
What is it for?
Use it to analyze screenshots, account for high-resolution Retina captures, guide UI implementation, and identify remaining visual differences.
Why use it?
It helps find exactly what is visually wrong instead of relying on guesswork. This is useful when a page looks close but still differs from the reference image.

Instructions file for CodexOpenCode

Written for Codex and OpenCode: the file is AGENTS.md.

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add instructions/tn0123/one-shot-ui/agents-md
Clone the repo
git clone --depth 1 https://github.com/TN0123/one-shot-ui

Made for: Codex, OpenCode.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for one-shot-ui AGENTS.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/tn0123/one-shot-ui/agents-md.svg)](https://agentmods.dev/instructions/tn0123/one-shot-ui/agents-md)
Your own site
<a href="https://agentmods.dev/instructions/tn0123/one-shot-ui/agents-md"><img src="https://agentmods.dev/badge/instructions/tn0123/one-shot-ui/agents-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 2,425 This file is loaded in full into every session.
When invoked 2,425 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.02425 $0.02425
Opus 5 $0.01213 $0.01213
Sonnet 5 $0.00485 $0.00485
Haiku 4.5 $0.00243 $0.00243

Measured 5d ago against content hash 9bdeb8dc493c, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

one-shot-ui AGENTS.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 5d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

AGENTS.md · 155 lines

How it starts

The opening of the file, as written. The whole thing — 155 lines — stays where its author put it; the contents beside it link to each section on GitHub.

one-shot-ui

Deterministic UI extraction and comparison toolkit. Use this tool to see what is wrong with a UI implementation compared to a reference screenshot.

Installation

npm install -g one-shot-ui
npx playwright install chromium    # only needed for capture/run commands

Core Workflow

  1. Extract — Analyze a reference screenshot into structured layout data: one-shot-ui extract reference.png --json For Retina/Mac screenshots, add --dpr 2 so font sizes and bounds are reported in CSS pixels (a 2x capture otherwise doubles every measurement). When omitted, scale is auto-detected; check the report's scale/units and re-run with --dpr 2 if it hints the image is Retina.

  2. Build — Use the extracted data (colors, spacing, typography, tokens) to build your implementation. The agent should write the UI code directly. Build to the rulers block (band heights, column edges + widths, gutter widths — all CSS px) to get sizing/spacing right the first time. Don't hand-draw icons/glyphs as SVG or CSS — use an icon library (the codebase's existing set, else lucide; @primer/octicons for GitHub-style UIs). Hand-drawn glyphs are the most common residual diff.

  3. Capture — Screenshot your implementation at the reference's exact scale: one-shot-ui capture --file ./index.html --match-reference reference.png --output impl.png --match-reference matches viewport AND device scale (a 2x Retina reference is captured at CSS dims @ 2x), so pixels line up without resize/crop. Add --reference-dpr 2 if the reference is Retina and the capture reports low DPR confidence.

  4. Compare — Diff reference vs implementation: one-shot-ui compare reference.png impl.png --json --heatmap heatmap.png Use summary.verdict (converged / not-converged + reasons) as your stop signal — not the pixel mismatchRatio, which is background-dominated and reads as "almost done" even when most elements are missing. Keep iterating until the verdict is converged. The report's spacing[] array gives deterministic, directly-CSS-able sizing/spacing deltas (BAND_HEIGHT_DELTA, EDGE_X_DELTA, GUTTER_DELTA) with concrete fixes — apply these first; they're the highest-trust path to closing the last-mile spacing gap. compare … --spacing prints just this list.

Read the full file on GitHub · 155 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 5d ago First seen · 155 lines · 2,425 tokens per session scan A 9bdeb8dc493c

Subscribe to this mod's changes

one-shot-ui AGENTS.md is an instructions file published in the GitHub repository TN0123/one-shot-ui (4 stars, last pushed 1mo ago), licensed MIT. It adds 2,425 tokens to every session, about $0.0121 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.