Skip to main content

Client Integration Notes

Fetch user balances inside Messenger​

When running inside Mixin Messenger you can call the in-app getAssets bridge to retrieve asset balances for the signed-in user.

window.assetsCallbackFunction = (assets) => {
  const parsed = JSON.parse(assets)
  if (!parsed) return

  parsed.forEach((asset) => {
    if (asset.asset_id === getEnvConfig().assetIdFund) {
      setBalance(asset.balance)
    }
  })
}

if (window.webkit?.messageHandlers?.MixinContext && window.webkit.messageHandlers.getAssets) {
  window.webkit.messageHandlers.getAssets.postMessage([[], 'assetsCallbackFunction'])
} else if (typeof window.MixinContext?.getAssets === 'function') {
  window.MixinContext.getAssets([], 'assetsCallbackFunction')
}

Precautions and tips​

  • Request and response formats – JWT and OAuth authentication work the same way as the legacy APIs. Any messenger-centric endpoints such as contacts, messages, or groups remain unchanged.
  • Memo encoding – Memo/extra payloads are now raw hex strings. Supply the exact bytes you want to persist; there is no implicit msgpack or base64 conversion.
  • New error code – Error code 10404 indicates that the target user has not yet registered with the Sequencer. Prompt the user to upgrade before retrying the action.
  • Batch transfers – Because Sequencer deals directly with Kernel transactions, you can create transactions that fan out to many recipients in one go by fetching multiple payment keys and constructing a single combined UTXO spend.