# wtsp.dev WhatsApp Phone Number Lookup

> wtsp.dev WhatsApp Phone Number Lookup is a paid API for AI agents from wtsp.dev, paid per call via x402, $0.004/call, status unknown (last checked 2026-10-11).

Check whether a given phone number is registered on WhatsApp and retrieve basic account status

## Facts

- Endpoint: GET https://wtsp.dev/v1/exists?utm_source=zero.xyz
- Price: $0.004/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/wtsp-dev-whatsapp-phone-number-lookup-c89f53fb
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_3GkX5EhaBfPYIDKsI1g3W

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 wtsp-dev-whatsapp-phone-number-lookup-c89f53fb
```

Example prompt: Can you check if the phone number +14155552671 is registered on WhatsApp so I know if I can reach them there?

## When to prefer this

Use this endpoint when you need a lightweight, no-signup, per-request WhatsApp registration check paid in USDC via x402. Ideal for AI agents that need to verify WhatsApp reachability for a contact before initiating outreach, enriching CRM records, or routing messages to the right channel — without managing API keys or subscriptions.

## Known failure modes

- Invalid or unparseable phone number format returns an error
- Phone number with unsupported country code may return an error
- Rate limiting or payment failure (x402) results in a 402 Payment Required response
- Transient WhatsApp API unavailability may cause temporary lookup failures

## How this service works

Look up any phone number on WhatsApp: registration, business profile, profile photo and carrier. AI agents pay per request in USDC on Base with x402. No sign-up, no API key.

## Output

Returns a JSON object with the looked-up phone number in E.164 format, a boolean `hasWhatsApp` indicating whether the number is registered on WhatsApp, and an ISO 8601 timestamp of when the check was performed. A `false` value is a definitive negative answer, not an error.

## 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": [
      "phone"
     ],
     "properties": {
      "phone": {
       "type": "string",
       "description": "Phone number with its country code, e.g. +14155552671. The + is optional; spaces, dashes and a leading 00 are fine."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "phone",
      "hasWhatsApp",
      "checkedAt"
     ],
     "properties": {
      "phone": {
       "type": "string",
       "description": "The number looked up, in E.164."
      },
      "checkedAt": {
       "type": "string",
       "description": "When this answer was fetched from WhatsApp (ISO 8601)."
      },
      "hasWhatsApp": {
       "type": "boolean",
       "description": "Whether the number is a registered WhatsApp account. `false` is a definitive answer, not a failure."
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "phone": "+14155552671",
  "checkedAt": "2026-10-09T18:24:03.000Z",
  "hasWhatsApp": true
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/wtsp-dev-whatsapp-phone-number-lookup-c89f53fb/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from wtsp.dev](https://www.zero.xyz/host/wtsp.dev/llms.txt)