What is yesterday-app-style?

A plugin entry for a visual and interaction guide used to build or review Yesterday Academy app screens and prototypes. It describes the product style and when the guide should be applied.

Use it when building, redesigning, reviewing, or prototyping a Yesterday Academy app surface or feature.

It helps an agent choose the Yesterday Academy design guide instead of treating the interface as a generic AI dashboard. The available plugin details do not specify extra implementation features.

yesterday-app-style — Plugin for Claude Code by Yesterday-AI/skills

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.

Clone the repo

git clone --depth 1 https://github.com/Yesterday-AI/skills

Made for: Claude Code.

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.

README.md

[![agentmods](https://agentmods.dev/badge/plugins/yesterday-ai/skills/yesterday-app-style/github.svg)](https://agentmods.dev/plugins/yesterday-ai/skills/yesterday-app-style)

Your own site

<a href="https://agentmods.dev/plugins/yesterday-ai/skills/yesterday-app-style"><img src="https://agentmods.dev/badge/plugins/yesterday-ai/skills/yesterday-app-style/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/plugins/yesterday-ai/skills/yesterday-app-style"><img src="https://agentmods.dev/badge/plugins/yesterday-ai/skills/yesterday-app-style.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session not measured What this adds to a session before it is invoked.

When invoked not measured The manifest loads nothing itself; its 1 skill cost 42 tokens a session between them.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Security

Grade A, and why

yesterday-app-style 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 1mo 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.

.compiled/skill-plugins/yesterday-app-style/.claude-plugin/plugin.json · 15 lines

What it actually says

{
  "name": "yesterday-app-style",
  "description": "Build or review Yesterday Academy app prototypes and features in the calm, clear, quietly confident product style. Use when a UI should feel like the Yesterday app rather than a generic AI dashboard.",
  "author": {
    "name": "Yesterday"
  },
  "homepage": "https://github.com/Yesterday-AI/skills/tree/main/.compiled/skill-plugins/yesterday-app-style",
  "repository": "https://github.com/Yesterday-AI/skills",
  "license": "MIT",
  "keywords": [
    "skills",
    "yesterday-app-style"
  ]
}

Contents

What it installs

The manifest is a name and a version. 1 skill travel with it, and installing the plugin installs all of them — 42 tokens a session between them. Each is measured on its own page, and each can be installed alone.

Skill yesterday-app-style A 42 tokens

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.

1mo ago First seen · 15 lines scan A 2beec945895a

Subscribe to this mod's changes

yesterday-app-style is a plugin published in the GitHub repository Yesterday-AI/skills (2 stars, last pushed 1mo ago), licensed MIT. Its token cost is not measured: this kind of file is read by the harness, not the model. 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 2026-10-14.

CSS and styling Design and UX Frontend agent-skills ai-agents claude-code-plugins cursor cursor-plugins

yesterday-app-style next to 6 plugins from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
yesterday-app-styleYesterday-AI/skills	Plugin	2	1mo ago	MIT	A	—	Claude Code
frontendErikaAX08/erikas-skills	Plugin	6	5d ago	Apache-2.0	A	—	Claude Code
cinematic-scrollMustBeSimo/cinematic-scroll-skill	Plugin	34	2mo ago	MIT	A	—	Claude Code
nightmarqueeant-dev-lab/nightmarquee-mcp	Plugin	1	1mo ago	MIT	A	—	Claude Code
humanizerblader/humanizer	Plugin	68k	3d ago	MIT	A	—	Claude Code
claude-plugins-official marketplaceanthropics/claude-plugins-official	Plugin	47k	today	Apache-2.0	A	—	Claude Code
nextjsvercel/next.js	Plugin	143k	today	MIT	A	—	Claude Code