# Make a Call (Vonage TTS)

> Make a Call (Vonage TTS) is a paid API for AI agents from ZeroClick x402 Service Registry at call.withzero.ai, paid per call via MPP, $0.05/call, not verified (last probed 2026-10-21); live alternatives: Abstract Phone Intelligence Lookup ($0.006) and BlockRun Phone Number Lookup ($0.01).

Agents call it through Zero, which pays per call: no API key and no wallet of your own. New accounts start with $5.

Live alternatives for the same use case:
- [Abstract Phone Intelligence Lookup](https://www.zero.xyz/c/phone-intelligence-lookup-68ab4a9d) ($0.006)
- [BlockRun Phone Number Lookup](https://www.zero.xyz/c/blockrun-phone-number-lookup-92e8041e) ($0.01)

Places an outbound phone call to a specified number and reads a text-to-speech message aloud via Vonage

## Facts

- Endpoint: POST https://call.withzero.ai/run?utm_source=zero.xyz
- Price: $0.05/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-21
- Last successful call: 2026-04-30
- Success rate: 17% of calls made through Zero
- Rating: 1.3 / 5 from 4 reviews
- Activations on Zero: 6
- Provider: ZeroClick x402 Service Registry
- Website: https://withzero.ai
- Tags: communication, call, phone, voice, vonage, nexmo, tts, text-to-speech, notification
- Canonical page: https://www.zero.xyz/c/zeroclick-x402-service-registry-make-a-call-vonage-tts-e3bfc8ff
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_3N2FhCoKqL5yTX2j8YHYI

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 zeroclick-x402-service-registry-make-a-call-vonage-tts-e3bfc8ff -d '<json body>'
```

Example prompt: Call +12125551234 and read them this message in a high-quality female voice in English: 'Your package has arrived and is waiting at the front desk. Please pick it up before 6pm today.'

## When to prefer this

Use this endpoint when you need to deliver a spoken voice message to a phone number programmatically, especially for notifications, alerts, or automated announcements. Prefer this over SMS when voice delivery is required. Best for single outbound calls with a specific message to speak.

## Known failure modes

- Invalid phone number format (not E.164) — validation error returned
- Trial account restriction: can only call pre-verified numbers — call fails with authorization error
- Message exceeds 5000 character limit — validation error
- Unsupported language code — TTS engine may fall back or error
- Recipient busy or unreachable — status returns busy or no-answer
- Payment failure (insufficient USDC) — call not placed

## How this service works

Make a phone call and deliver a text-to-speech message via Vonage (formerly Nexmo). Input: `to` (E.164 phone number like +12125551234), `message` (text to speak, max 5000 chars), optional `voice` ("alice" for high quality, "man", or "woman"), optional `language` (BCP-47 code like en-US). Returns: `callSid` (Vonage call UUID for tracking), `status` (queued/ringing/in-progress/completed/failed), `to` and `from` numbers, `dateCreated` (ISO timestamp), `estimatedDurationSec` (rough speech duration). The call rings the recipient, plays the spoken message, then hangs up. TRIAL ACCOUNT: may only call pre-verified numbers. Status returned is the initial status - the call proceeds asynchronously.

## Output

Returns a callSid (Vonage call UUID for tracking), initial call status (e.g. queued or ringing), the to and from phone numbers, an ISO timestamp of when the call was created, and an estimated speech duration in seconds. The call proceeds asynchronously after the initial response.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "to",
  "message"
 ],
 "properties": {
  "to": {
   "type": "string",
   "pattern": "^\\+[1-9]\\d{6,14}$",
   "description": "Phone number in E.164 format (e.g. +12125551234)"
  },
  "voice": {
   "enum": [
    "alice",
    "man",
    "woman"
   ],
   "type": "string",
   "default": "alice",
   "description": "Text-to-speech voice. \"alice\" is high quality, \"man\" and \"woman\" are classic TTS voices."
  },
  "message": {
   "type": "string",
   "maxLength": 5000,
   "minLength": 1,
   "description": "Text message to speak to the call recipient (max 5000 characters)"
  },
  "language": {
   "type": "string",
   "default": "en-US",
   "description": "BCP-47 language code for TTS (e.g. en-US, en-GB, es-ES, fr-FR, de-DE, ja-JP, zh-CN). Vonage supports many languages via its TTS engine."
  }
 },
 "additionalProperties": false
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "callSid",
  "status",
  "to",
  "from",
  "dateCreated",
  "estimatedDurationSec"
 ],
 "properties": {
  "to": {
   "type": "string",
   "description": "Recipient phone number"
  },
  "from": {
   "type": "string",
   "description": "Caller phone number"
  },
  "status": {
   "type": "string",
   "description": "Call status: queued, ringing, in-progress, completed, failed, busy, no-answer, canceled"
  },
  "callSid": {
   "type": "string",
   "description": "Twilio call SID for tracking (e.g. CA...)"
  },
  "dateCreated": {
   "type": "string",
   "description": "ISO 8601 timestamp when call was initiated"
  },
  "estimatedDurationSec": {
   "type": "number",
   "description": "Estimated speech duration in seconds (based on ~150 words/min)"
  }
 },
 "additionalProperties": false
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/zeroclick-x402-service-registry-make-a-call-vonage-tts-e3bfc8ff/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from call.withzero.ai](https://www.zero.xyz/host/call.withzero.ai/llms.txt)