# PageDiff API - Historical Page-Change Evidence

> PageDiff API - Historical Page-Change Evidence is a paid API for AI agents from pagediff-api.hahavoid0.workers.dev, paid per call via x402, $0.5/call, status unknown (last checked 2026-09-14).

Compares two Wayback Machine snapshots of a URL across specified dates and generates a structured change-intelligence report with diffs, risk notes, and commercial impact analysis.

## Facts

- Endpoint: GET https://pagediff-api.hahavoid0.workers.dev/report
- Price: $0.5/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/pagediff-api-historical-page-change-evidence-4052f692
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_9G0SRC6oaFPYe9IxgCNGH

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 pagediff-api-historical-page-change-evidence-4052f692
```

Example prompt: Pull an archived page-change report for https://stripe.com/pricing comparing January 1 2023 to January 1 2024, using the pricing_intelligence report type — I want to see what pricing language was added, removed, or modified and any commercial impact notes.

## When to prefer this

Choose this endpoint when you need structured, timestamped evidence of how a specific webpage changed between two historical dates — especially for pricing intelligence, competitor positioning, policy tracking, legal terms audits, or documentation drift. Prefer it over raw Wayback Machine lookups when you want pre-parsed diffs with commercial impact framing and risk notes rather than raw HTML comparison.

## Known failure modes

- No Wayback snapshot available near the requested date — API may return incomplete or null snapshot data
- JavaScript-rendered or authenticated pages may produce incomplete diffs
- Low confidence result when snapshots are sparse or content is dynamic
- Request for a URL never archived by the Wayback Machine returns no usable snapshot
- Date range too narrow — snapshots may resolve to the same archived version

## How this service works

Pay-per-call historical page-change evidence for AI agents. Check Wayback snapshot availability, compare archived pages, and generate structured reports with important changes, impact, risks, and source timestamps.

## Output

A structured JSON report including: a headline summary of changes detected, a diff_summary with added/removed/modified counts and change level, an array of important_changes describing specific additions and removals, commercial_impact bullet points, risk_notes about snapshot availability and limitations, source_snapshots with Wayback archive URLs and timestamps for both dates, a confidence rating, a next_action recommendation, and URLs to the full report JSON.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "to": {
   "type": "string",
   "examples": [
    "2024-01-01"
   ],
   "description": "Requested later snapshot date in YYYY-MM-DD format."
  },
  "url": {
   "type": "string",
   "examples": [
    "https://example.com/"
   ]
  },
  "from": {
   "type": "string",
   "examples": [
    "2023-01-01"
   ],
   "description": "Requested earlier snapshot date in YYYY-MM-DD format."
  },
  "report_type": {
   "enum": [
    "pricing_intelligence",
    "policy_change",
    "competitor_positioning",
    "docs_drift",
    "legal_terms_change",
    "general"
   ],
   "type": "string",
   "default": "general"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "url": "https://example.com/",
  "summary": "Compared 20230101000000 to 20240101000000. Change level: low. Added: 1. Removed: 1. Modified: 0.",
  "headline": "2 archived text changes detected for pricing intelligence.",
  "json_url": "https://pagediff-api.hahavoid0.workers.dev/reports/r_example.json",
  "report_id": "r_example",
  "confidence": "medium",
  "report_url": "https://pagediff-api.hahavoid0.workers.dev/reports/r_example",
  "risk_notes": [
   "Results depend on Internet Archive snapshot availability and quality.",
   "JavaScript-rendered, authenticated, or poorly archived content may be incomplete.",
   "This report is machine-generated evidence triage, not legal advice or certified web capture."
  ],
  "next_action": "Review the source snapshots, then run /report on adjacent dates or related pages to isolate when the change first appeared.",
  "report_type": "pricing_intelligence",
  "diff_summary": {
   "added_count": 1,
   "change_level": "low",
   "removed_count": 1,
   "modified_count": 0
  },
  "source_snapshots": {
   "to": {
    "digest": "EXAMPLE2",
    "mimetype": "text/html",
    "timestamp": "20240101000000",
    "statuscode": "200",
    "archive_url": "https://web.archive.org/web/20240101000000id_/https://example.com/",
    "original_url": "https://example.com/",
    "requested_date": "2024-01-01"
   },
   "from": {
    "digest": "EXAMPLE",
    "mimetype": "text/html",
    "timestamp": "20230101000000",
    "statuscode": "200",
    "archive_url": "https://web.archive.org/web/20230101000000id_/https://example.com/",
    "original_url": "https://example.com/",
    "requested_date": "2023-01-01"
   }
  },
  "commercial_impact": [
   "Review packaging, limits, trial language, and enterprise call-to-action changes before updating competitive positioning.",
   "If pricing language changed, treat this as a signal to inspect sales motion, margin pressure, or segmentation changes."
  ],
  "important_changes": [
   "Added: Updated example page content.",
   "Removed: Original example page content."
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/pagediff-api-historical-page-change-evidence-4052f692/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from pagediff-api.hahavoid0.workers.dev](https://www.zero.xyz/host/pagediff-api.hahavoid0.workers.dev/llms.txt)