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.

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

It helps identify changes between two data snapshots without fetching pages, paying for another observation, or retrying a request.

page-change — Skill for Claude Code and Codex by epistemedeus

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.

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.

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 0 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 916 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.

Model	Per session	Once invoked
Fable 5.1	$0.00000	$0.00916
Opus 5.5	$0.00000	$0.00366
Sonnet 5.5	$0.00000	$0.00183
Haiku 4.5	$0.00000	$0.00092

Measured 1mo ago against content hash f2b21d318438, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, 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 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.

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.

1mo ago Changed · -55 tokens per session f2b21d318438
1mo 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 yesterday), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 916 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 2026-09-09.

Analytics and metrics agentic-commerce ai-agents api base usdc x402

page-change next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
page-changeepistemedeus/x402-url-extractor	Skill	1	yesterday	MIT	A	0	Claude Code, Codex
x402Starchild-ai-agent/official-skills	Skill	32	yesterday	none	A	125	Claude Code, Codex
bankr-shopifyBankrBot/skills	Skill	1.2k	today	none	A	163	Claude Code, Codex
scvd-general-storeseancrecord/scvd-general-store-repo	Skill	3	4d ago	MIT	A	79	Claude Code
scvd-x402-verificationseancrecord/scvd-general-store-repo	Skill	3	4d ago	MIT	A	40	Claude Code
scvd-x402-verificationseancrecord/scvd-general-store-repo	Skill	3	4d ago	MIT	A	40	Claude Code
x402-before-you-payseancrecord/scvd-general-store-repo	Skill	3	4d ago	MIT	A	90	Claude Code