page-change

page-change is a skill for Claude Code, Codex from epistemedeus/x402-url-extractor. It costs 55 tokens per session (899 once invoked), scanned A, original, MIT.

An offline comparison tool for two already-saved batch JSON files. It compares selected fields and reports differences, failed or missing rows, and unknown coverage.

In plain words
What is it for?
Use it to compare two delivered POST /extract/batch results and review which records or fields changed or are missing.
Why use it?
It helps identify changes between two data snapshots without fetching pages, paying for another observation, or retrying a request.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Needs its repository: it runs a file that does not travel with it, so clone the repository first. The line is npm run page-change -- job --job ./fixtures/page-change/customer-job/job.json.

Good fit Use it to compare two delivered POST /extract/batch results and review which records or fields changed or are missing.

Compare 6 skills from other repositories ↓
Install

Getting it into your agent

It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.

Clone the repo
git clone --depth 1 https://github.com/epistemedeus/x402-url-extractor
agentmods
npx agentmods add skills/epistemedeus/x402-url-extractor/page-change

Made for: Claude Code, Codex.

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 page-change

README.md
[![agentmods](https://agentmods.dev/badge/skills/epistemedeus/x402-url-extractor/page-change/github.svg)](https://agentmods.dev/skills/epistemedeus/x402-url-extractor/page-change)
Your own site
<a href="https://agentmods.dev/skills/epistemedeus/x402-url-extractor/page-change"><img src="https://agentmods.dev/badge/skills/epistemedeus/x402-url-extractor/page-change/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.

agentmods 80×15 button for page-change

Your own site · 80×15
<a href="https://agentmods.dev/skills/epistemedeus/x402-url-extractor/page-change"><img src="https://agentmods.dev/badge/skills/epistemedeus/x402-url-extractor/page-change.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 55 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 899 The whole file, excluding the scripts and references it only reads on demand.
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.
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 $0.00055 $0.00899
Opus 5 $0.00028 $0.00449
Sonnet 5 $0.00011 $0.00180
Haiku 4.5 $0.00006 $0.00090

Measured 3d ago against content hash 24a197775f91, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

page-change 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 3d 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.

plugins/samedaydesk-x402/skills/page-change/SKILL.md · 103 lines

How it starts

The opening of the file, as written. The whole thing — 103 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Compare two delivered extract-batch artifacts

This skill compares two already delivered SameDayDesk POST /extract/batch JSON files for caller-selected fields. It does not fetch URLs, sign, send payment headers, retry, or schedule a second purchase.

If the caller still needs a first or second batch delivery, stop this recipe and use the existing web-extract skill plus the public customer example for unpaid preflight. Pay only with separate explicit customer approval of that example. This skill is not payment-capable.

When to Use

  • The caller already has two batch JSON artifacts (fixture, saved delivery, or other local files they supply).
  • They want selected-field diffs, failed/missing rows, and coverage unknowns made explicit.
  • Do not use this skill to browse live pages, construct a paid request, or fill gaps from a prior partial by buying again.

Prerequisites

Work from a full public repository checkout of epistemedeus/x402-url-extractor, not a separately packed npm tarball:

cd examples/customer-x402
npm ci

Requires Node.js 22 or newer. Source-identity helpers live at the repository root. The comparison covers selected values in the supplied artifacts; it does not validate the full seller output schema or prove downstream business utility.

How to Run

Show fictional or local supplied artifacts first.

From examples/customer-x402 after npm ci:

npm run page-change -- job --job ./fixtures/page-change/customer-job/job.json
npm run page-change -- compare \
  --before ./fixtures/page-change/customer-job/before.json \
  --after ./fixtures/page-change/customer-job/after.json \
  --fields title,description,headings \
  --format text

The fixture pair is owner proof that selected-field before/after, failed rows, missing rows, and coverage unknowns stay visible. It is not buyer demand. charged: true is not useful output.

Two existing public client deliveries the caller already saved:

npm run page-change -- compare \
  --before /path/to/first-delivery.json \
  --after /path/to/second-delivery.json \
  --fields title,description,headings \
  --clock 2026-09-08T12:00:00.000Z \
  --max-stale-ms 86400000

Read the full file on GitHub · 103 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. 3d ago First seen · 103 lines · 55 tokens per session scan A 24a197775f91

Subscribe to this mod's changes

page-change is a skill published in the GitHub repository epistemedeus/x402-url-extractor (1 stars, last pushed today), licensed MIT. It adds 55 tokens to every session and 899 once invoked, about $0.0003 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 2026-09-09.

Related

Other skills, from other repositories

x402

Monetize any user project/service with the x402 payment protocol on platform networks (Base + Monad + Robinhood + X Layer + Solana; Starchild platform billing: payperuse / lifetime / weekly / monthly / quarterly / yearly / prepaid, plus multi-plan services), limited-time free promotions (amount-0 verify, no…

Starchild-ai-agent/official-skills · 125 tokens

bankr-shopify

Shopify Admin & Storefront GraphQL APIs via curl, with Bankr-native bridges. Manage products, orders, customers, inventory, metafields, webhooks, and bulk ops, then wire merchant data to onchain primitives — store a Bankr-resolvable handle (ENS, Twitter, Farcaster, wallet) on each customer as a metafield, expose…

BankrBot/skills · 163 tokens

scvd-general-store

A live x402 practice counter: real settlement, no sandbox, from $0.001. Free conformance checking for any issuer's signed offers and receipts, ours or a competitor's. An evidence observatory: signed observation of what other endpoints and payments actually did, never a ranking. Reachable six ways, including browser…

seancrecord/scvd-general-store-repo · 79 tokens

x402-before-you-pay

Before an agent pays an x402 endpoint, read its 402 terms and run scvd.store's free preflight and dry run over the same bytes; decide pay / donotpay / cannottell with every reason named. Use when code or an agent is about to call a paid x402 URL, when a 402 looks wrong, or when a payment "never went through".…

seancrecord/scvd-general-store-repo · 90 tokens

agent-payment-stats

Cross-protocol agent-economy payment metrics from Barker's index. x402 (Base) volume is on-chain verifiable; ACP / AP2 / MPP / AP4M figures are self-reported claims. Separates real vs nominal volume by filtering wash/noise sellers. Use when users ask about x402 volume, agent payment stats, agent economy metrics, or…

barkermoney/barker-mcp · 134 tokens

fetcher

Shared payment and setup skill for fetcher.sh, a pay-per-call web-data API covering Twitter/X, TikTok, Instagram, YouTube, Reddit, Google Search, Google Maps, Google News, Google Play, the App Store, and Yelp. Use this skill whenever a task needs a fetcher.sh API key, a credit top-up, an x402 micropayment, MCP server…

fetcher-sh/fetcher-skills · 188 tokens