Transactions
- All transactions MUST transfer value (value > 0).
- The value is always transferred from transaction sender to transaction recipient.
- The hash of the transaction does not include the signature/proof.
- All transactions in Nimiq have a maximum validity window of 120 blocks, approximately two hours.
- Transactions in Nimiq do not use a nonce, reoccurring, identical transactions can be send only once the previous transaction has been invalidated or mined.
Basic transaction
Size-Optimized format (138 bytes) for simple value transfer from basic to basic account.
| Element | Data type | Bytes | Description |
|---|---|---|---|
| Type | uint8 | 1 | 0 |
| sender | raw | 32 | Public key of sender |
| recipient | Address | 20 | Recipient’s address |
| value | uint64 | 8 | In Luna |
| fee | uint64 | 8 | Miner fee |
| validity start height | uint32 | 4 | Delay by blocks, defaults to current height + 1 |
| network id | uint8 | 1 | Network ID (mainnet = 42) |
| signature | raw | 64 | By sender’s private key |
To make a transaction validity shorter than the default of 120 blocks, set the start height to a value before the current blockchain height. For example, current height - 60 will result in a remaining livetime of 60 blocks, approximately one hour.
Extended transaction
Each extended transaction is at least 68 (3+|data|+65+|proof|) bytes long.
| Element | Data type | Bytes | Description |
|---|---|---|---|
| Type | uint8 | 1 | 1 |
| data length | uint16 | 2 | Maximum 64 |
| data | raw | data length | Intended for recipient |
| sender | Address | 20 | |
| sender type | uint8 | 1 | Account type of sender |
| recipient | Address | 20 | |
| recipient type | uint8 | 1 | Account type of recipient |
| value | uint64 | 8 | |
| fee | uint64 | 8 | Fee for miner to include tx in a block |
| validity start height | uint32 | 4 | Delay by blocks, defaults to current height + 1 |
| network id | uint8 | 1 | Network ID (mainnet = 42) |
| flags | uint8 | 1 | Unknown flags must be 0; Contract Creation (0x1) |
| proof length | uint16 | 2 | |
| proof | raw | proof length | Validity depends on sender account type, account state, current block height |
Transaction hash
A hash of a transaction is created by using Blake2b on all the fields of an extended transaction, without type, proof length, and proof.