# RelayShield SIM Swap Detection

> RelayShield SIM Swap Detection is a paid API for AI agents from api.relayshield.net, paid per call via x402, $0.25/call, status unknown (last checked 2026-09-14).

Checks whether a given phone number has had a SIM swap performed recently, returning carrier and swap timestamp details

## Facts

- Endpoint: POST https://api.relayshield.net/v1/payg/sim-swap
- Price: $0.25/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/relayshield-sim-swap-detection-3642b0ee
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Qw1lMNgT6mCiVLKdcnLcJ

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 relayshield-sim-swap-detection-3642b0ee -d '<json body>'
```

Example prompt: Before we process this login, can you check if +14155551234 has had a SIM swap recently — I want to make sure the phone number hasn't been hijacked.

## When to prefer this

Use this endpoint when you need to detect SIM swap fraud as part of an authentication or fraud-prevention pipeline, especially before sending OTP codes or approving high-value transactions. Prefer this over generic phone validation APIs when you specifically need SIM swap history and carrier attribution, not just number formatting or reachability checks.

## Known failure modes

- Phone number not found or unsupported carrier returns error or null swap data
- Invalid phone number format causes a 400-level error
- Carrier data unavailable or rate-limited results in incomplete response
- Network timeout or upstream carrier API failure returns non-ok response

## How this service works

RelayShield Landing Site

## Output

Returns a JSON object with ok:true and a data object containing the phone number, current carrier name, a boolean indicating whether a swap occurred, the timestamp when the check was performed, and if swapped, the timestamp of the swap event.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "phone": {
   "type": "string",
   "description": "Phone number in E.164 format"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "data": {
   "phone": "+14155551234",
   "carrier": "T-Mobile",
   "swapped": true,
   "checked_at": "2026-05-19T10:00:00+00:00",
   "swap_timestamp": "2026-05-18T14:23:00Z"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/relayshield-sim-swap-detection-3642b0ee/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.relayshield.net](https://www.zero.xyz/host/api.relayshield.net/llms.txt)