SDK backup mode

const LINK_TOKEN_URL = 'https://integration-api.meshconnect.com/api/v1/linktoken'
const sleep = (ms) => new Promise((resolve) => setTimeout(resolve, ms))

// True only for failures that signal a Mesh outage
const isOutage = (res) => !res || res.status === 429 || res.status >= 500

async function startMeshSession(linkTokenRequest, backupConfig) {
  for (let attempt = 1; attempt <= 2; attempt++) {
    let res = null
    try {
      res = await fetch(LINK_TOKEN_URL, {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json',
          'X-Client-Id': process.env.MESH_CLIENT_ID, // Replace
          'X-Client-Secret': process.env.MESH_API_KEY, // Replace
        },
        body: JSON.stringify(linkTokenRequest),
        signal: AbortSignal.timeout(4000), // 3–5s ceiling
      })
    } catch {
      res = null // Network, DNS, or timeout error: no HTTP response
    }

    if (res?.ok) {
      const { content } = await res.json()
      return { mode: 'normal', linkToken: content.linkToken }
    }

    // 4xx other than 429: a request or credential problem. Fix it; don't fall back.
    if (!isOutage(res)) throw new Error(`Link token request failed: ${res.status}`)

    if (attempt === 1) await sleep(300) // One quick retry
  }

  return { mode: 'backup', backupConfig } // Mesh outage: switch to backup mode
}

{
  "clientId": "YOUR_CLIENT_ID",
  "userId": "UNIQUE_USER_ID",
  "preselectedSymbol": "USDC",
  "destinations": [
    {
      "networkId": "03dee5da-7398-428f-9ec2-ab41bcb271da",
      "symbol": "BTC",
      "address": "xxx"
    },
    {
      "networkId": "e3c7fdd8-b1fc-4e51-85ae-bb276e075611",
      "symbol": "USDC",
      "address": "xxx"
    },
    {
      "networkId": "0291810a-5947-424d-9a59-e88bb33e999d",
      "symbol": "USDC",
      "address": "xxx"
    },
    {
      "networkId": "0ea47ee7-9d36-460e-a2d5-64cfa8a1dddd",
      "symbol": "XRP",
      "address": "xxx",
      "addressTag": "xxx"
    },
    {
      "networkId": "aa883b03-120d-477c-a588-37c2afd3ca71",
      "symbol": "USDC"
    }
  ]
}

const link = createLink({
  onIntegrationConnected,
  onTransferFinished,
  onEvent,
  onExit,
  // Required only if any destination omits `address`
  onAddressInit: (symbol, networkId) =>
    api.post('/wallets/addresses/assign', { currency: symbol, network_id: networkId }), // Replace with your backend call
  onStatusPoll: (symbol, networkId) =>
    api.get('/wallets/deposit_addresses', { currency: symbol }).then((res) => { // Replace with your backend call
      const match = res.deposit_addresses.find((a) => a.network_id === networkId && a.address)
      return match
        ? { status: 'ready', address: match.address, addressTag: match.address_tag }
        : { status: 'pending' }
    }),
})

const session = await api.post('/mesh/session') // Replace: your server runs the outage check from step 1

if (session.mode === 'normal') {
  link.openLink(session.linkToken)
} else {
  link.openLinkBackup(session.backupConfig) // Outage path: no Link token
}

import { LinkConnect } from '@meshconnect/react-native-link-sdk'

// Normal path: render with a Link token
<LinkConnect
  linkToken={linkToken}
  onIntegrationConnected={onIntegrationConnected}
  onTransferFinished={onTransferFinished}
  onEvent={onEvent}
  onExit={onExit}
/>

// Backup path: MeshBackupConfig instead of a Link token
<LinkConnect
  backupConfig={backupConfig}
  // Required only if any destination omits `address`
  onAddressInit={(symbol, networkId) =>
    // Starts address generation. The return value is ignored; the widget moves to polling.
    api.post('/wallets/addresses/assign', { currency: symbol, network_id: networkId }) // Replace
  }
  onStatusPoll={(symbol, networkId) =>
    // Must resolve to { status, address?, addressTag? }
    api.get('/wallets/deposit_addresses', { currency: symbol }).then((res) => { // Replace
      const match = res.deposit_addresses.find((a) => a.network_id === networkId && a.address)
      return match
        ? { status: 'ready', address: match.address, addressTag: match.address_tag }
        : { status: 'pending' }
    })
  }
  onIntegrationConnected={onIntegrationConnected}
  onTransferFinished={onTransferFinished}
  onEvent={onEvent}
  onExit={onExit}
/>