# StablePhone AI Call

> StablePhone AI Call is a paid API for AI agents from StablePhone at stablephone.dev, paid per call via MPP or x402, $0.54/call, status unknown (last checked 2026-10-12, last successful call 2026-09-03).

Initiates an AI-powered outbound phone call to a US number with a specified task/script, returning a call_id for status tracking.

## Facts

- Endpoint: POST https://stablephone.dev/api/call?utm_source=zero.xyz
- Price: $0.54/call
- Payment: MPP, x402
- Status: unknown
- Last checked: 2026-10-12
- Last successful call: 2026-09-03
- Success rate: 90% of calls made through Zero
- Rating: 4.5 / 5 from 16 reviews
- Activations on Zero: 106
- Provider: StablePhone
- Docs: https://stablephone.dev
- Website: https://stablephone.dev
- Tags: phone, call, voice, ai-call, imessage, ai, social
- Canonical page: https://www.zero.xyz/c/stablephone-call-9dc16e0e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_1fKUN2gFIEp1f_-FoKaCs

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 stablephone-call-9dc16e0e -d '<json body>'
```

Example prompt: Call +12025550123 and tell them their package has arrived and they should pick it up by 5pm today — if they don't answer, leave a voicemail with the same message and hang up after 5 minutes.

## When to prefer this

Use this endpoint when you need to deliver spoken information or gather responses via an outbound phone call to a US number, especially for appointment confirmations, reminders, or notifications. Prefer over SMS/email when voice interaction is required or when the recipient is more likely to respond to a call.

## Known failure modes

- 403 Forbidden — phone number is on the Do-Not-Call (DNC) list; do not retry
- 402 Payment Required — insufficient balance or payment not provided
- 400 Bad Request — invalid phone number format (must be E.164 US +1XXXXXXXXXX) or task too long/empty
- 500 Internal Server Error — call could not be queued

## How this service works

Make an AI phone call ($0.54). Send a phone number and task, get back a call_id to track status. Returns 403 if the number is on the Do-Not-Call (DNC) list — do not retry DNC numbers.

## Output

Returns a JSON object with success: true, a UUID call_id to track the call's progress and retrieve the transcript later, and a confirmation message ('Call successfully queued.').

## Example request

```json
{
 "task": "Hello, this is a test call to verify the system is working. Please press 1 if you received this message.",
 "model": "base",
 "max_duration": 5,
 "phone_number": "+12025550123",
 "voicemail_action": "hangup",
 "wait_for_greeting": true
}
```

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "phone_number",
  "task"
 ],
 "properties": {
  "from": {
   "type": "string",
   "pattern": "^\\+1\\d{10}$"
  },
  "task": {
   "type": "string",
   "maxLength": 4000,
   "minLength": 1
  },
  "model": {
   "enum": [
    "base",
    "turbo"
   ],
   "type": "string"
  },
  "voice": {
   "type": "string"
  },
  "record": {
   "type": "boolean"
  },
  "metadata": {
   "type": "object",
   "propertyNames": {
    "type": "string"
   },
   "additionalProperties": {}
  },
  "max_duration": {
   "type": "integer",
   "maximum": 30,
   "minimum": 1
  },
  "phone_number": {
   "type": "string",
   "pattern": "^\\+1\\d{10}$"
  },
  "first_sentence": {
   "type": "string",
   "maxLength": 500
  },
  "voicemail_action": {
   "enum": [
    "hangup",
    "leave_message",
    "ignore"
   ],
   "type": "string"
  },
  "voicemail_message": {
   "type": "string",
   "maxLength": 500
  },
  "wait_for_greeting": {
   "type": "boolean"
  },
  "transfer_phone_number": {
   "type": "string"
  }
 },
 "additionalProperties": false
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "success",
  "call_id",
  "message"
 ],
 "properties": {
  "call_id": {
   "type": "string"
  },
  "message": {
   "type": "string"
  },
  "success": {
   "type": "boolean",
   "const": true
  }
 },
 "additionalProperties": false
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/stablephone-call-9dc16e0e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from stablephone.dev](https://www.zero.xyz/host/stablephone.dev/llms.txt)