# Text Length Limits Checker

> Text Length Limits Checker is a paid API for AI agents from text-metrics.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-21).

Checks a piece of text against SMS segment limits (GSM-7 vs Unicode), tweet character weight, meta description, title tag, and push notification length constraints.

## Facts

- Endpoint: GET https://text-metrics.x402tookit.com/length-limits?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/text-length-limits-checker-176d7cdc
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_N_45BOSgnvAsYNmbwvyg6

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 text-length-limits-checker-176d7cdc
```

Example prompt: Can you check whether this message fits in a single SMS and tell me if it would use GSM-7 or Unicode encoding? Here's the text: 'Thanks for your order! Your package has shipped and will arrive by Friday. Track it at: example.com/track/12345'

## When to prefer this

Choose this endpoint when you need a fast, multi-platform text length validation in a single call — especially when SMS segment counting and encoding detection (GSM-7 vs Unicode) matter alongside SEO and social limits. It is ideal for content pipelines, marketing copy tools, and SMS campaign validators that need to know both character counts and platform-specific limit compliance simultaneously. Prefer it over manual counting or single-platform tools when you need a comprehensive snapshot across SMS, Twitter, SEO tags, and push notifications at once.

## Known failure modes

- Missing required 'text' query parameter returns an error
- Text exceeding 3000 characters may be rejected or truncated
- Service unavailable or payment failure returns a non-200 response
- Degraded mode may return partial results with a disclaimer flag
- Non-printable or binary input may produce unreliable encoding detection

## How this service works

Check text against SMS segments (GSM-7 vs Unicode), tweet weight, meta description, title tag and push notification limits.

## Output

Returns a structured object with SMS segment count, encoding type (GSM-7 or Unicode), characters per segment, and per-platform limit comparisons (tweet, title tag, meta description, push notification, SMS single segment) showing how many characters are used vs. the limit for each. Also includes word, sentence, paragraph, and total character counts, a summary verdict, a list of which limits were exceeded, and optionally a disclaimer about degraded results.

## 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": [
      "text"
     ],
     "properties": {
      "text": {
       "type": "string",
       "description": "The text, up to 3000 characters"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "sms": {
       "type": [
        "null",
        "object"
       ],
       "properties": {
        "units": {
         "type": [
          "null",
          "number"
         ]
        },
        "encoding": {
         "type": [
          "null",
          "string"
         ]
        },
        "segments": {
         "type": [
          "null",
          "number"
         ]
        },
        "perSegment": {
         "type": [
          "null",
          "number"
         ]
        }
       }
      },
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "over": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "words": {
       "type": [
        "null",
        "number"
       ]
      },
      "limits": {
       "type": [
        "null",
        "object"
       ],
       "properties": {
        "tweet": {
         "type": [
          "null",
          "object"
         ],
         "properties": {
          "used": {
           "type": [
            "null",
            "number"
           ]
          },
          "limit": {
           "type": [
            "null",
            "number"
           ]
          }
         }
        },
        "titleTag": {
         "type": [
          "null",
          "object"
         ],
         "properties": {
          "used": {
           "type": [
            "null",
            "number"
           ]
          },
          "limit": {
           "type": [
            "null",
            "number"
           ]
          }
         }
        },
        "metaDescription": {
         "type":
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/text-length-limits-checker-176d7cdc/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from text-metrics.x402tookit.com](https://www.zero.xyz/host/text-metrics.x402tookit.com/llms.txt)