Ramps
Sign in

Quickstart

Quickstart · React Native custodial cash-out (Stellar)

WebView custodial cash-out: RAMPS_DEPOSIT_ADDRESS, omnibus transfer, and sandbox reference number.

~20 minCustodialReact NativeUSDC

Quickstart · React Native custodial cash-out (Stellar / USDC)

Time: about 20 minutes · Success: WebView loads the widget; your app receives a deposit address, your server transfers USDC from the omnibus wallet, and the sandbox flow returns a reference number.

Before you start

  • Credentials & environments (API keys for widget partners), or Sign in if you already have a partner account
  • React Native app with a WebView
  • Omnibus / hot wallet funded with testnet USDC
  • Confirmed you are custodial (you move customer USDC; users do not sign)

Wrong track? User-owned wallets → RN non-custodial Quickstart. Web custodial → Web custodial Quickstart.

1. Server session endpoint with customerIdentifier

Same rule as Web: secret key stays on the server. Your app calls your backend; the backend calls MoneyGram POST /v1/sessions with a stable internal user ID.

TypeScript
const res = await fetch('https://playground.xramps.moneygram.com/api/v1/sessions', {  method: 'POST',  headers: {    'Content-Type': 'application/json',    'x-api-key': process.env.MONEYGRAM_SK!,  },  body: JSON.stringify({    customerIdentifier: authenticatedUserId,    walletAddress: process.env.PARTNER_OMNIBUS_WALLET,    chain: 'stellar',  }),})const session = await res.json()

2. Load the widget in a WebView (custodial)

On RAMPS_READY, post RAMPS_CONFIG with walletType: 'custodial' and your omnibus wallet G-address (not the end user's address).

Handle RAMPS_DEPOSIT_ADDRESS (not RAMPS_SIGN_TRANSACTION):

TypeScript
case 'RAMPS_DEPOSIT_ADDRESS': {  const { address, amount, memo } = payload  try {    // Your backend must authenticate this request and validate address,    // amount, and memo against the customer's active Ramps transaction    // (looked up server-side) before moving any funds. Never authorize a    // transfer from values the WebView supplied alone.    const res = await fetch(INTERNAL_TRANSFER_URL, {      method: 'POST',      headers: { 'Content-Type': 'application/json', Authorization: `Bearer ${appAuthToken}` },      body: JSON.stringify({ to: address, amount, memo, chain: 'stellar', asset: 'USDC' }),    })    if (!res.ok) throw new Error(`Transfer failed (${res.status})`)    const { txHash } = await res.json()    if (typeof txHash !== 'string' || !txHash) throw new Error('Transfer returned no txHash')    post('RAMPS_SIGN_SUCCESS', { txHash, walletAddress: PARTNER_OMNIBUS_WALLET })  } catch (err) {    post('RAMPS_SIGN_ERROR', { error: err instanceof Error ? err.message : 'Transfer failed' })  }  break}

3. What success looks like

  • Session created with a stable customerIdentifier
  • WebView opens MoneyGram UI without blank-screen / cookie issues
  • Deposit address step triggers your internal transfer
  • Hot-wallet Stellar transfer confirms (memo included when required)
  • Widget surfaces a sandbox reference number

4. Go deeper