Transaction Processing

Every Burstcoin wallet acts as a node supporting transaction processing when connected to the network.

Transaction Types

Ordinary fund transfers and messaging are just two of the many types of transactions that can be made using Burstcoin.

Transaction Fees

Burstcoin uses a slot-based transaction fee structure.  The lowest fee is just .00735.

Offline Signing

Individual transaction can be signed on an offline device, transferred to a connected device and broadcast to the network using offline transaction signing.  This allows passphrases to be held offline and never exposed to the internet.

Documentation

To improve submit improve this document, provide updates, or recommend improvements, use the submission form at the bottom of this page or visit the documentation project.

Minimum transaction fee

The minimum transaction for all types of Burstcoin transactions is .00735 burst (735.000 Plancks).

Burstcoin use a now slot-based transaction fee structure.

At block height 500,200 Burstcoin changed its transaction fee structure from “1 burst per transaction” to a progressive slot-based structure.  Burstcoin’s slot based transaction fee system is described in the Burst Dymaxion whitepaper.

The slot-based transaction fee system allows for variable fees depending on the blockchain’s transaction load.  This prevents spamming blocks with minimum fee transactions.  Transactions that are only created because they require little or no investment consume space on the blockchain.  It is important to conserve blockchain space in order to keep the cost of operating a public node at a minimum.

Technical Information

A block is divided into 1,020 slots that can each hold one transaction. The fees for the slots increase progressively in a linear fashion.  The fee for each slot is calculated by multiplying the slot number by the lowest minimum fee  (slot# * 0.00735 burst).  The lowest minimum fee is referred to as ‘fee quant’.  Ordinary transactions and multi-out transactions use the same fee structure.  The highest fee is 7.497 burst. The total fees collected for a block where all of slots are filled with the minimal required fee is 3827.2185 BURST.

Assignment of transactions to slots

When a new block is generated, new (currently unconfirmed) transactions are assigned to the available slots. Here, each transaction is assigned to the most costly slot it fits in. If no slot is available, the transaction is not included in the block and remains unconfirmed in the mempool of the node. For included transactions, left-over funds for the slot are not refunded. This means if a transaction specifies a fee of 0.01 BURST and is assigned to the first slot which costs 0.00735 BURST, it will still cost 0.01 BURST to process the transaction. It is up to the user to choose a reasonable fee that does not waste funds.

Example 1

A (legacy) fee of 1 Burst guarantees inclusion into a block with less than 136 transactions.

Example 2

A fee of 0.1 Burst guarantees inclusion into a block with less than 13 transactions.

Example 3

A more complex example of transaction assignment to slots is shown in the following:

Fee Quantum: 0.00735
Block Capacity: 10
Fee slots:

10: 0.0735
9: 0.06615
8: 0.0588
7: 0.05145
6: 0.0441
5: 0.03675
4: 0.0294
3: 0.02205
2: 0.0147
1: 0.00735

Pending Tx fees (descending-sorted and filtered too low):

$VAR1 = [
‘0.3’,
‘0.2’,
‘0.1’,
‘0.008’
];

Distributing as follows:
0.3 has slot @ 10 -> added
0.2 has slot @ 9 -> added
0.1 has slot @ 8 -> added
skipped slot @ 7 (0.008 too low for 0.05145).
skipped slot @ 6 (0.008 too low for 0.0441).
skipped slot @ 5 (0.008 too low for 0.03675).
skipped slot @ 4 (0.008 too low for 0.0294).
skipped slot @ 3 (0.008 too low for 0.02205).
skipped slot @ 2 (0.008 too low for 0.0147).
0.008 has slot @ 1 -> added

 

 Fee types

Unconfirmed transactions can be issued with arbitrary fees, with the lowest possible fee being 0.00735000 Burst (735.000 Plancks). Depending on the fee amount, unconfirmed transactions will either execute or be delayed until a slot for that fee amount is available.

The Burstcoin wallet is equipped with a fee suggestion tool which suggests the fee amount to be used for a transaction based on the transaction load on the chain in the last 10 blocks. The fee suggestion tool offers three fee amounts:

  • Standard: 50% probability the transaction will be included in the next block
  • Cheap: 50% probability the transaction will be included in the next 10 blocks
  • Priority: 90% probability the transaction will be included in the next block, 99% probability the transaction will be included in the next two blocks.

The fee suggestion tool can also be used using The Burst API.

13 + 1 =