Web Interface Guidelines is a practical set of recommendations for making website interfaces usable, accessible, and consistent. Web developers use it when building interfaces with any framework, including React and Next.js. The catalogue entry provides these guidelines as an instruction for coding agents.
Borrowing it
Nothing to install: this file belongs to vercel-labs/web-interface-guidelines. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/vercel-labs/web-interface-guidelines/main/AGENTS.mdgit clone --depth 1 https://github.com/vercel-labs/web-interface-guidelinesWrote 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.
[](https://agentmods.dev/instructions/vercel-labs/web-interface-guidelines/agents-md)<a href="https://agentmods.dev/instructions/vercel-labs/web-interface-guidelines/agents-md"><img src="https://agentmods.dev/badge/instructions/vercel-labs/web-interface-guidelines/agents-md/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.
<a href="https://agentmods.dev/instructions/vercel-labs/web-interface-guidelines/agents-md"><img src="https://agentmods.dev/badge/instructions/vercel-labs/web-interface-guidelines/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.01958 | $0.01958 |
| Opus 5.5 | $0.00783 | $0.00783 |
| Sonnet 5.5 | $0.00392 | $0.00392 |
| Haiku 4.5 | $0.00196 | $0.00196 |
Grade A, and why
web-interface-guidelines 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 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.
How it starts
The opening of the file, as written. The whole thing — 157 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Concise rules for building accessible, fast, delightful UIs. Use MUST/SHOULD/NEVER to guide decisions.
Interactions
Keyboard
- MUST: Full keyboard support per WAI-ARIA APG
- MUST: Visible, unobscured focus rings (
:focus-visible; group with:focus-within); sticky/fixed elements never cover focus - MUST: Manage focus (trap, move, return) per APG patterns
- NEVER:
outline: nonewithout visible focus replacement
Targets & Input
- MUST: Hit target ≥24px (mobile ≥44px); if visual <24px, expand hit area
- MUST: Mobile
<input>font-size ≥16px to prevent iOS zoom - NEVER: Disable browser zoom (
user-scalable=no,maximum-scale=1) - MUST:
touch-action: manipulationto prevent double-tap zoom - SHOULD: Set
-webkit-tap-highlight-colorto match design
Forms
- MUST: Hydration-safe inputs (no lost focus/value)
- NEVER: Block paste in
<input>/<textarea> - MUST: Loading buttons show spinner and keep original label
- MUST: Enter submits focused input; in
<textarea>, ⌘/Ctrl+Enter submits - MUST: Keep submit enabled until request starts; then disable with spinner
- MUST: Accept free text, validate after—don't block typing
- MUST: Allow incomplete form submission to surface validation
- MUST: Errors inline next to fields; on submit, focus first error
- MUST:
autocomplete+ meaningfulname; correcttypeandinputmode - SHOULD: Disable spellcheck for emails/codes/usernames
- SHOULD: Placeholders end with
…and show example pattern - MUST: Warn on unsaved changes before navigation
- MUST: Compatible with password managers & 2FA; allow pasting codes
- MUST: Trim values to handle text expansion trailing spaces
- MUST: No dead zones on checkboxes/radios; label+control share one hit target
State & Navigation
- MUST: URL reflects state (deep-link filters/tabs/pagination/expanded panels)
- MUST: Back/Forward restores scroll position
- MUST: Links use
<a>/<Link>for navigation (support Cmd/Ctrl/middle-click) - NEVER: Use
<div onClick>for navigation
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 Changed · +1 lines · +71 tokens per session 35411b4a2dcf
- 2mo ago First seen · 156 lines · 1,887 tokens per session scan A 113bce3da621
web-interface-guidelines AGENTS.md is an instructions file published in the GitHub repository vercel-labs/web-interface-guidelines (1,118 stars, last pushed 1mo ago), licensed MIT. It adds 1,958 tokens to every session, about $0.0078 per session on Opus 5.5. 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 2026-08-30.
web-interface-guidelines AGENTS.md compared with instructions from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| web-interface-guidelines AGENTS.mdvercel-labs/web-interface-guidelines | Instructions file | 1.1k | 1mo ago | MIT | A | 1,958 | Codex, OpenCode |
| vscode buildNext.instructions.mdmicrosoft/vscode | Instructions file | 195k | today | MIT | A | 9,719 | GitHub Copilot |
| next.js AGENTS.mdvercel/next.js | Instructions file | 143k | today | MIT | A | 7,461 | Codex, OpenCode |
| langchain AGENTS.mdlangchain-ai/langchain | Instructions file | 149k | today | MIT | A | 4,680 | Codex, OpenCode |
| vscode oss-third-party-notices.instructions.mdmicrosoft/vscode | Instructions file | 195k | today | MIT | A | 5,516 | GitHub Copilot |
| vscode copilot-instructions.mdmicrosoft/vscode | Instructions file | 195k | today | MIT | A | 3,093 | GitHub Copilot |
| deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness | Instructions file | 274k | 2d ago | MIT | A | 4,313 | Codex, OpenCode |