2. Sequentia Overview
Sequentia is a new blockchain network with its own wallets, block explorers, and services. It is an open-source project, and every developer is free to contribute, fork the codebase, or create alternative software following the consensus/protocol RFC.
Sequentia is defined as a sidechain by virtue of the anchoring mechanism (§3.4) between Sequentia blocks and Bitcoin blocks. The link to Bitcoin also affects the chain’s technical architecture and the consensus system, resulting in a hybrid mechanism employing both Bitcoin Proof of Work and the stake-based governance of a Proof of Stake system.
Sequentia blocks are created by users who have enough stake in the chain in terms of Sequence (SEQ) tokens, but unlike most PoS networks, there is not a specific token to pay for transaction fees over Sequentia; any token can be accepted by block creators, in a free market of transaction fees (§3.2). This lack of a native fee token reduces friction in the user experience and improves scalability.
Any developer is free to create a different wallet and node. However, some specifications are recommended for those developers building on Sequentia and willing to stick to the fundamental principles illustrated in this White Paper.
Ideally, a Sequentia wallet should have multi-token support and the following basic multi-token functionalities:
- Store, send, and receive Bitcoin as any other traditional Bitcoin wallet
- Store, send, and receive tokens issued or pegged on the chain, known as RAS tokens (where RAS stands for Regular Assets on Sequentia §4.2), including Sequence (SEQ) tokens, the governance utility token of the Sequentia blockchain.
- Allow users to manually set on-chain fees, choosing the specific token to pay fees with and the amount. The possibility to query a service for the calculation of fees is recommended.
- Allow replace-by-fee and child-pays-for-parent functionalities; this is particularly necessary because acceptance of transactions by the block creator is optional, depending on the token chosen by the user sending the transaction.
- Process Bitcoin script smart contracts.
In addition, it is preferable that the wallet also allows users to:
- Use the Lightning Network for transactions (BTC and RASs).
Ideally, a Sequentia full node offers all the wallet functionalities listed before, plus the following:
- Stake SEQ tokens to become a “participant” in the network.
- As a “participant”, propose or countersign blocks and earn transaction fees.
- Create a RAS token by executing a Sequentia on-chain transaction.
- Connect to services to query for DEX data (such as the DHT order book, see §5.4). Standard wallet API may be provided so that oracles can be programmed to help build smart contracts on Sequentia using third-party information.
A Sequentia full node retrieves information regarding the Bitcoin blockchain from the Bitcoin network, ideally a self-hosted Bitcoin Core full node.
Also, Sequentia full nodes may eventually implement utreexo (2), which compacts the size of the UTXO set down to 1 KB. As such, pruned nodes will never take up more than around 1.5 GB of space (about three days of blockchain at maximum throughput), even in the long run.