txjson (XRP ledger transaction in JSON format) sent to the xumm API (or SDK) may slightly differ from the XRP ledger requirements.
Some fields will be automatically filled by the xumm App if omitted, and some fields will be modified by the xumm App based on the transaction & user account properties.
Fee (in drops, one millionth XRP) may be omitted. The fee will then be determined by xumm based on network load. A default value of 12 drops will be used, and a maximum value of 0.1 XRP (100,000 drops).
If the fee is specified in the payload, the provided fee will be used. The xumm App will accept a provided up to 0.1 XRP (100,000 drops). If a higher fee is provided, the fee will be determined as if no fee was specified.
Only in case of transactions specifically requiring higher fees (like an AccountDelete transaction, where a 5 XRP (5,000,000 drops) fee is mandatory) a fee above 0.1 XRP (100,000 drops) will be accepted by xumm.
The account sequence may be omitted, and will be fetched by the xumm App from the XRP ledger when signing.
When a sign request contains a request in an IOU currency (issued asset) and the end user doesn't have this IOU setup (no TrustLine present), the xumm application will fall back to a DEX transaction, exchanging XRP for the requested IOU value. A partial payment flag will then automatically be added to the transaction.
This will only happen if no
Flags property is specified. To disable this behaviour, provide an (unused, as this is default behaviour on the XRP ledger)
RequireFullyCanonicalSig flag, as the
Flags field will not be touched if present.
This field may be omitted, as sign requests can be signed asynchronously by xumm app users at their convenience, the passed max. ledger sequence may be already in the past. You may want to provide a LastLedgerSequence relevant to the ledger index when the user opens the sign request.
LastLedgerSequence is entered with a value < 32570 xumm will handle and replace the value. It will be considered a relative value from the current ledger index at the moment the user taps the Accept (sign) button in xumm.
Updated about 1 year ago