# Forms — Prior Text-Set Comparison

> Forms — Prior Text-Set Comparison is a paid API for AI agents from market.datapackvibe.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-16).

Compares current text content of a specified HTML form element against a set of previously known texts to detect changes or differences.

## Facts

- Endpoint: POST https://market.datapackvibe.com/x402/assistant-bx-web-forms-compare?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/forms-prior-text-set-comparison-0e1e8327
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_IWEC9nb6kyaBFlubtLNHb

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 forms-prior-text-set-comparison-0e1e8327 -d '<json body>'
```

Example prompt: Check the form with id 'signup' on https://example.com/register and compare its current text against these previous versions: 'Sign up for free', 'Create your account' — tell me if the text has changed.

## When to prefer this

Choose this endpoint when you need to compare the current static text of a specific HTML form element against a known set of prior text values — ideal for change detection, content monitoring, or pre-submission verification workflows. Best suited for pages that render form content in static HTML without requiring JavaScript execution or authentication.

## Known failure modes

- URL unreachable or returns non-200 status — no content to parse
- HTML provided does not contain a form element matching the specified attribute/value combination
- JavaScript-rendered content not available since only static HTML parsing is performed
- previous_texts array is empty — no baseline to compare against
- Form element found but contains no text content
- attribute pattern validation fails if attribute name contains invalid characters

## How this service works

Forms — Prior text-set comparison: Prior text-set comparison for Forms. One public HTTPS page or supplied HTML; static parsing, no JavaScript rendering, login or access bypass. Specialised preset in a shared 50-profile, 20-operation engine. 0.01 USDC includes one bounded prior text-set comparison result.

## Output

Returns a bounded prior text-set comparison result indicating whether the current text content of the targeted form element matches, partially matches, or differs from the supplied previous texts array, along with the extracted current text.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "default": "",
   "maxLength": 2048
  },
  "html": {
   "type": "string",
   "default": "<!doctype html><html><head></head><body><form id=\"sample\" data-kind=\"example\">Example product guide</form></body></html>",
   "maxLength": 100000
  },
  "term": {
   "type": "string",
   "default": "product",
   "maxLength": 100,
   "minLength": 1
  },
  "attribute": {
   "type": "string",
   "default": "id",
   "pattern": "^[a-zA-Z][a-zA-Z0-9:_-]{0,49}$",
   "maxLength": 50
  },
  "previous_texts": {
   "type": "array",
   "items": {
    "type": "string",
    "default": "",
    "maxLength": 1000
   },
   "default": [
    "Older example"
   ],
   "maxItems": 200,
   "minItems": 0
  },
  "attribute_value": {
   "type": "string",
   "default": "sample",
   "maxLength": 200
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/forms-prior-text-set-comparison-0e1e8327/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)