# CSS Design Calc – WCAG 2.2 Target Size Checker

> CSS Design Calc – WCAG 2.2 Target Size Checker is a paid API for AI agents from css-design-calc.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-30).

Validates a click/touch target's dimensions against WCAG 2.2 AA (24 px) and AAA (44 px) target size criteria, including the spacing exception for nearby undersized targets.

## Facts

- Endpoint: GET https://css-design-calc.x402tookit.com/target-size?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/css-design-calc-wcag-2-2-target-size-checker-6ce04d01
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_G5UfhUzcRr8uKOjMySVe1

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 css-design-calc-wcag-2-2-target-size-checker-6ce04d01
```

Example prompt: Can you check if my submit button — 32 px wide and 28 px tall — passes WCAG 2.2 AA and AAA target size requirements? The nearest other small button is 30 px away center-to-center.

## When to prefer this

Use this endpoint when you need a precise, standards-referenced verdict on whether a specific UI element meets WCAG 2.2 target size criteria (SC 2.5.8 AA and SC 2.5.5 AAA), including the nuanced spacing exception. Prefer it over manual calculations when you also want Apple HIG and Material Design compliance checked simultaneously, or when you need the exact padding required to bring a target into compliance.

## Known failure modes

- Missing required widthPx or heightPx query parameters returns an error
- Non-numeric or negative values for dimensions may produce unexpected results
- neighbourCenterDistancePx omitted means spacing exception cannot be evaluated and is reported as not checked
- Service unavailability returns a non-200 HTTP status

## How this service works

Check a click or touch target against WCAG 2.2 target size (24 px AA, 44 px AAA) including the spacing exception.

## Output

Returns a detailed object including pass/fail verdicts for WCAG 2.2 AA (2.5.8, 24 px) and AAA (2.5.5, 44 px) criteria, whether the spacing exception applies, the smaller side in px, shortfall amounts to each threshold, padding needed to meet AA, Apple HIG and Material Design compliance flags, a human-readable summary, and a list of reasons explaining the verdict.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "widthPx",
      "heightPx"
     ],
     "properties": {
      "widthPx": {
       "type": "number",
       "description": "Target width in CSS px (the clickable box)"
      },
      "heightPx": {
       "type": "number",
       "description": "Target height in CSS px"
      },
      "neighbourCenterDistancePx": {
       "type": "number",
       "description": "Centre-to-centre distance to the nearest OTHER undersized target, px (for the spacing exception)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "summary": {
       "type": [
        "null",
        "string"
       ]
      },
      "verdict": {
       "type": [
        "null",
        "string"
       ]
      },
      "widthPx": {
       "type": [
        "null",
        "number"
       ]
      },
      "degraded": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "heightPx": {
       "type": [
        "null",
        "number"
       ]
      },
      "disclaimer": {
       "type": [
        "null",
        "string"
       ]
      },
      "notChecked": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "meetsBySize": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "smallerSidePx": {
       "type": [
        "null",
        "number"
       ]
      },
      "meetsBySpacing": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "meetsWcag258Aa": {
       "type": [
        "boolean",
        "null"
   
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/css-design-calc-wcag-2-2-target-size-checker-6ce04d01/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from css-design-calc.x402tookit.com](https://www.zero.xyz/host/css-design-calc.x402tookit.com/llms.txt)