# Public Page Changes with Source Evidence

> Public Page Changes with Source Evidence is a paid API for AI agents from market.datapackvibe.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-12).

Fetches a public HTTPS page, diffs its text against a previous snapshot, and returns added/removed lines plus exact quotes for up to 5 search terms, headings, and links.

## Facts

- Endpoint: POST https://market.datapackvibe.com/x402/assistant-public-page-change-evidence?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/public-page-changes-with-source-evidence-cadd14c6
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_UpgCMF9NrBuLQMmedzdwK

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability public-page-changes-with-source-evidence-cadd14c6 -d '<json body>'
```

Example prompt: Check https://www.example.com/pricing for any changes since my last snapshot — look for the terms 'pro plan', 'enterprise', and 'free trial', and compare against the snapshot I saved last week so I can see exactly what lines were added or removed.

## When to prefer this

Choose this endpoint when you need a lightweight, on-demand diff of a single public static webpage against a known previous state, with built-in evidence quotes for specific search terms. It is ideal when you already hold a snapshot and want to verify exact changes rather than just detecting that a page changed. Prefer it over general web scrapers when you need structured change evidence (added/removed lines + term quotes) in a single call without managing background monitoring infrastructure. Not suitable for JavaScript-heavy SPAs, login-gated pages, or bulk crawling of multiple URLs.

## Known failure modes

- URL is not publicly accessible or requires login — returns error, no content fetched
- Page content exceeds 12,000 characters — text is truncated and text_truncated flag is set to true
- Previous snapshot SHA-256 or schema is malformed — validation error returned
- URL uses JavaScript rendering to load content — only static HTML text is captured, dynamic content may be missing
- Network timeout or unreachable host — returns fetch error
- More than 5 search terms supplied — rejected by input validation

## How this service works

Public Page Changes with Source Evidence: Read one public HTTPS page and compare its static text with your previous snapshot. Returns added/removed lines, exact quotes for up to 5 search terms, headings, links and a reusable snapshot. Max 12,000 text characters; reports truncation. No login, JavaScript rendering or background monitoring; call again when needed. 0.01 USDC includes one public page, up to 5 terms and one caller-supplied previous snapshot.

## Output

Returns a structured object containing: lists of added and removed text lines (diff vs. previous snapshot), exact surrounding quotes for each requested search term, extracted page headings, extracted links, and a reusable snapshot object (with URL, retrieval timestamp, full text up to 12,000 chars, SHA-256 hash, and a truncation flag) that can be passed as the 'previous' input on the next call.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "default": "https://www.iana.org/help/example-domains",
   "maxLength": 2048
  },
  "terms": {
   "type": "array",
   "items": {
    "type": "string",
    "maxLength": 80,
    "minLength": 1
   },
   "default": [
    "example",
    "domain"
   ],
   "maxItems": 5
  },
  "previous": {
   "type": [
    "object",
    "null"
   ],
   "default": null,
   "required": [
    "version",
    "requested_url",
    "source_url",
    "retrieved_at",
    "text",
    "sha256",
    "text_truncated"
   ],
   "properties": {
    "text": {
     "type": "string",
     "maxLength": 12000
    },
    "sha256": {
     "type": "string",
     "pattern": "^[0-9a-f]{64}$"
    },
    "version": {
     "enum": [
      1
     ],
     "type": "integer"
    },
    "source_url": {
     "type": "string",
     "maxLength": 2048
    },
    "retrieved_at": {
     "type": "string",
     "maxLength": 40
    },
    "requested_url": {
     "type": "string",
     "maxLength": 2048
    },
    "text_truncated": {
     "type": "boolean"
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/public-page-changes-with-source-evidence-cadd14c6/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from market.datapackvibe.com](https://www.zero.xyz/host/market.datapackvibe.com/llms.txt)