# Tinstop Website Change Diff API

> Tinstop Website Change Diff API is a paid API for AI agents from tinstop.com, paid per call via x402, $0.05/call, status unknown (last checked 2026-09-15).

Fetches a URL and computes a diff against a baseline or last stored snapshot to detect content changes

## Facts

- Endpoint: POST https://tinstop.com/v1/site/change-diff
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/tinstop-website-change-diff-api-f182c1e4
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_T7t9jacqrQz0lP-p8y7wl

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 tinstop-website-change-diff-api-f182c1e4 -d '<json body>'
```

Example prompt: Check if https://example.com/pricing has changed since the last snapshot — show me what's different.

## When to prefer this

Choose this endpoint when you need to detect whether a specific webpage has changed over time, either against a provided baseline or a previously stored snapshot. It is ideal for automated monitoring pipelines, security audits checking for defacement, or competitive intelligence workflows where tracking page mutations matters. Prefer this over generic scraping APIs when you specifically need change detection semantics rather than raw content extraction.

## Known failure modes

- URL is unreachable or returns a non-200 status — diff cannot be performed
- No stored snapshot exists for the URL and no baseline_text was provided — nothing to compare against
- URL is malformed or not an absolute http/https URL — request rejected
- Payment failure via x402 — request blocked before execution
- The target page blocks crawlers or returns CAPTCHA — fetched content may be empty or misleading

## How this service works

Tinstop is a machine-payable Website Intelligence API for domain security and performance audits: DNS, SSL/TLS, HTTP security headers, SPF/DKIM/DMARC email authentication, and Google PageSpeed. Pay per call with x402 using USDC on Base. No accounts or API keys.

## Output

Returns a structured diff object showing what content has been added, removed, or modified between the current fetched page and either the provided baseline text or the last stored snapshot for that URL. The response includes change details indicating what sections of the HTML or text have changed.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "description": "Absolute http(s) URL to fetch and diff."
  },
  "baseline_text": {
   "type": "string",
   "description": "Optional baseline text/HTML. If omitted, compares against the last stored snapshot for this URL."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "title": "Response Site Change Diff V1 Site Change Diff Post",
 "additionalProperties": true
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/tinstop-website-change-diff-api-f182c1e4/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from tinstop.com](https://www.zero.xyz/host/tinstop.com/llms.txt)