# Phone Number E.164 Format Validator

> Phone Number E.164 Format Validator is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-02).

Validates whether a phone number string conforms to the E.164 international format standard (no carrier lookup)

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/check-phone-e164?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/phone-number-e-164-format-validator-948eff34
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_KLeGPbZATqe6WHdWhVQy6

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 phone-number-e-164-format-validator-948eff34 -d '<json body>'
```

Example prompt: Can you check if the phone number +14155552671 is correctly formatted in E.164 — just format validation, no carrier lookup needed?

## When to prefer this

Choose this endpoint when you only need to verify that a phone number string is structurally valid per the E.164 standard and do not need carrier information, line type, or number portability data. It is the cheapest option at $0.001 USDC per call. Always try the free sandbox endpoint POST /v1/sandbox/check-phone-e164 first during development or testing before using this paid endpoint.

## Known failure modes

- Empty or missing value field returns an error
- Value exceeding 20000 characters rejected
- Malformed request body returns 400
- Payment not attached or insufficient USDC returns 402
- Network timeout or service unavailability returns 5xx

## How this service works

Call when an agent needs whether a phone number matches E.164. No carrier lookup. Exact $0.001 USDC. Prefer unpaid POST /v1/sandbox/check-phone-e164 first.

## Output

A boolean or structured response indicating whether the provided phone number string conforms to E.164 format (starts with +, followed by up to 15 digits, correct length and structure). No carrier or line-type information is returned.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "data": {
   "description": "JSON value for schema-check SKUs. Omit it on string checks such as email or IBAN."
  },
  "value": {
   "type": "string",
   "examples": [
    "+14155552671"
   ],
   "maxLength": 20000,
   "minLength": 1,
   "description": "Value to check. The route description names the format: email, phone, IBAN, postal code, VAT, national id, or similar."
  },
  "schema": {
   "description": "JSON Schema document for schema-check SKUs. Omit it on string checks."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/phone-number-e-164-format-validator-948eff34/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agentshelf.syntexa.ch](https://www.zero.xyz/host/agentshelf.syntexa.ch/llms.txt)