Tomorrow ~10:00 UTC we will deploy an emergency update that breaks backward compatibility. The decoded external message body for wallets_v4r2 will now use a SumType for the payload.
You can see the difference at the following two URLs:
https://dev.tonapi.io/v2/blockchain/transactions/3d3ad440cd5d1c5bb089695338f250d19707659e4444c98756fcc0d444558346 - new version
https://tonapi.io/v2/blockchain/transactions/3d3ad440cd5d1c5bb089695338f250d19707659e4444c98756fcc0d444558346 - old version
It doesn’t affect you if you haven’t used the
decoded_body field for external messages in raw transactions or traces.