add-proxy-page

add-proxy-page is a command for Claude Code from mentilead/shopify-app-skill. It costs 0 tokens per session (561 once invoked), scanned A, original, MIT.

A coding command for creating a Shopify App Proxy page, a page shown through a shop’s storefront URL while being served by the app. It sets up request verification and HTML with its styles included directly in the page.

In plain words
What is it for?
Use it for storefront-facing pages such as application forms or order-status lookups. Form submissions that need POST requests must use a separate app endpoint.
Why use it?
It handles Shopify’s restrictions for proxy pages, including GET-only requests and no external CSS or JavaScript files. This avoids building a page that works in the app but fails through the storefront.

Command for Claude Code

Written for Claude Code: $ARGUMENTS substitution. Also seen: reads .claude/ paths.

Part of the shopify-app-skill plugin — 1 skill, 10 commands shipped together

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 commands/mentilead/shopify-app-skill/add-proxy-page
Clone the repo
git clone --depth 1 https://github.com/mentilead/shopify-app-skill

Made for: Claude Code.

Or install shopify-app-skill, the plugin that ships this one along with the rest of its 1 skill, 10 commands.

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 add-proxy-page

README.md
[![agentmods](https://agentmods.dev/badge/commands/mentilead/shopify-app-skill/add-proxy-page.svg)](https://agentmods.dev/commands/mentilead/shopify-app-skill/add-proxy-page)
Your own site
<a href="https://agentmods.dev/commands/mentilead/shopify-app-skill/add-proxy-page"><img src="https://agentmods.dev/badge/commands/mentilead/shopify-app-skill/add-proxy-page.svg" alt="Measured on agentmods" height="20"></a>
Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 561 The whole file, excluding the scripts and references it only reads on demand.
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 $0.00000 $0.00561
Opus 5 $0.00000 $0.00280
Sonnet 5 $0.00000 $0.00112
Haiku 4.5 $0.00000 $0.00056

Measured 6d ago against content hash 5b036b15d646, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

add-proxy-page 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 6d 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.

commands/add-proxy-page.md · 36 lines

How it starts

The opening of the file, as written. The whole thing — 36 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Add App Proxy Page

Scaffold a new App Proxy page with HMAC verification, inline CSS, and server-rendered HTML.

Arguments

$ARGUMENTS = page description (e.g., "application form for job applicants", "order status lookup")

Instructions

  1. Parse the page purpose from $ARGUMENTS. If empty, ask the user what the proxy page should display.
  2. Read .claude/skills/shopify-app/references/app-proxy-patterns.md for constraints, HMAC verification, and CSS inlining patterns.
  3. Read .claude/skills/shopify-app/SKILL.md gotcha #6 (App Proxy: GET only, no external CSS/JS).
  4. Determine the route filename:
    • If this is a new proxy layout: app/routes/proxy.tsx (layout) + app/routes/proxy.<page>.tsx
    • If extending existing proxy: app/routes/proxy.<page>.tsx
  5. Review proxy constraints before writing code:
    • GET only — the proxy only forwards GET requests. POST submissions must target the direct app URL (/api/* route).
    • No external CSS/JS — all CSS must be inline <style> tags. No <link> or <script src>.
    • No Tailwind ?inline — Tailwind 4's Vite plugin doesn't process ?inline imports.
    • No client-side hydration — React Router JS bundles don't load. Server-render only.
  6. Create the route file with:
    • loader that calls verifyProxySignature(searchParams) for HMAC verification
    • Server-rendered HTML with all CSS inline in <style> tags
    • Proper Content-Type: text/html response (or use Shopify's Liquid layout via application_liquid content type)
    • Data fetched from service functions, scoped by the shop from the HMAC-verified params
  7. If the page needs form submissions:
    • Create a separate app/routes/api.<form-name>.tsx action route for POST handling
    • The proxy page form's action attribute must point to the direct app URL, not the proxy URL
    • Read .claude/skills/shopify-app/references/react-router-patterns.md for API route patterns
  8. Create or update service functions as needed, always with shopDomain as first parameter.
  9. Remind the user to:
    • Configure the App Proxy in the Shopify Partner Dashboard (URL prefix + subpath)
    • Test HMAC verification with a real storefront request
    • Verify no external CSS/JS references leaked into the HTML

Read the full file on GitHub · 36 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. 6d ago First seen · 36 lines · 0 tokens per session scan A 5b036b15d646

Subscribe to this mod's changes

add-proxy-page is a command published in the GitHub repository mentilead/shopify-app-skill (5 stars, last pushed 6mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 561 tokens. 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.