xls: 23
  title: Lite Accounts
  description: A proposal for lite accounts with reduced account reserves but limited features
  author: Wietse Wind (@WietseWind)
  discussion-from: https://github.com/XRPLF/XRPL-Standards/discussions/56
  status: Stagnant
  category: Amendment
  created: 2021-08-27

LiteAccounts Amendment¶

By @RichardAH, @WietseWind

Introduction¶

The XRP Ledger is a fast consensus-based blockchain which, unlike competing chains, maintains its user's balances as persistent state rather than as a graph of unspent transaction outputs. This imposes unique per-account storage costs on the network. These costs are passed on to the user.

The cost of creating an account on the ledger is, at time of writing, 5 XRP with an additional lockup of 15 XRP (which is redeemable if the account is later deleted). Collectively this is known as the Account Reserve. It has been argued the Account Reserve acts as a barrier to entry for new users and remains a major impedement to the expansion of the ecosystem.

The AccountRoot ledger object represents the authoritative state of an XRPL account.

It contains the following fields:

Field	Type	Bytes	Required	Lite Account
sfLedgerEntryType	UInt16	3	✅	✅
sfFlags	UInt32	5	✅	✅
sfAccount	AccountID	22	✅	✅
sfSequence	UInt32	5	✅	✅
sfBalance	Amount	9	✅	✅
sfOwnerCount	UInt32	5	✅	✅
sfPreviousTxnID	UInt256	33	✅	✅
sfPreviousTxnLgrSeq	UInt32	5	✅	✅
sfAccountTxnID	UInt256	33
sfRegularKey	AccountID	22
sfEmailHash	UInt128	17
sfWalletLocator	UInt256	33
sfWalletSize	UInt32	5
sfMessageKey	Blob	33
sfTransferRate	UInt32	5
sfDomain	Blob	at most 256
sfTickSize	UInt8	4
sfTicketCount	UInt32	6
sfSponsor^^	AccountID	22		✅

^^ Part of this proposal

An XRPL Account which owns no on-ledger objects (i.e: does not have any trustlines, escrows, offers, etc.), does not specify a regular key and does not set any of its other optional fields has a serialized size of 87 bytes (excluding storage overhead.)

We propose that any such minimal account root imposes such a small burden on the ledger that it should be able to be treated differently to full account roots.

Lite Accounts¶

We propose that a lite account is an XRPL Account with:

• a minimal account root
• the new asfLiteAccount account flag set, and,
• (optionally) the new sfSponsor field set.

Lite accounts have an Account Reserve of 1/5th the ledger's object reserve (i.e. 1 XRP at time of writing.)¶

⚠️ Restrictions¶

A lite account cannot:

• Own on-ledger objects, and thus cannot:
• Hold or create Trustline balances
• Have non-default limits on incoming trustlines
• Create Offers
• Create Escrows
• Create Checks
• Create Payment Channels
• Create or install Hooks (pending amendment)
• Set or use a Signer List
• Create Tickets
• Require or use Deposit Authorizations
• Set or use a Regular Key
• Become a sponsor for another lite account
• Perform AccountSet on any fields except sfSponsor and sfFlags

New Fields and Flags¶

The following changes are made to fields and flags.

1. sfSponsor — a new optional AccountID field on the acount root which indicates that another account owns the reserve for the account root.
2. tfSponsor — a new transaction flag that indicates the intent of the sender to create and sponsor a new lite account.
3. asfLiteAccount — a new account flag that can be set and unset subject to certain conditions, which indicates that the account is a lite account and subject to the restrictions of a lite account.

These are explained in further detail below.

Sponsorship¶

Lite accounts may be sponsored. Sponsorship provides that another account pays the account reserve and, subject to conditions, is entitled to recover the entire account reserve should the lite account be later deleted. Full accounts cannot be sponsored, only accounts with asfLiteAccount flag can be sponsored.

To sponsor a new account creation: A ttPAYMENT transaction is created and successfully submitted, which:

1. Specifies an unfunded destination account,
2. Specifies the (new) tfSponsor flag, and
3. Sends at least as much XRP as the lite account reserve.

There is no way for an already established XRPL account (full or lite) to subsequently become a sponsored account. Sponsorship can only occur through account creation.

Reclamation¶

A sponsor is entitled to reclaim the Account Reserve on a lite account (for which they are the sponsor) subject to certain conditions:

Scenario 1: AccountDelete¶

If a sponsored lite account:

• contains less than two times the lite account reserve, and
• does not sign and submit any transaction that results in a tesSUCCESS on a validated ledger for more than 1 million ledgers,

Then the account's sponsor may recover the Account Reserve via an AccountDelete transaction. The spsonsor also receives the remaining balance in the lite account.

The AccountDelete transaction specifies the lite account as the sfAccount field but is signed by the sponsor.

Scenario 2: AccountSet¶

If a sponsored lite account, at any time:

• contains at least two times the lite account reserve

Then the account's sponsor may recover the Account Reserve via an AccountSet transaction that clears the sfSponsor field.

The AccountSet transaction specifies the lite account as the sfAccount field but is signed by the sponsor and can only be used to delete the sfSponsor field.

Doing so results in a balance mutation on both the lite account and the sponsor account to reflect the return of the lite Account Reserve.

Upgrading¶

The owner of a lite account can upgrade their account twice:

Scenario 1: Removal of Sponsor¶

The owner of a lite account may unilaterally unsponsor his or her own account by:

• ensuring the account contains at least twice the lite Account Reserve, and
• creating and successfully submitting an AccountSet transaction that clears the sfSponsor field.

Doing so results in a balance mutation on both the lite account and the sponsor account to reflect the return of the lite Account Reserve.

Scenario 2: Full Account¶

The owner of an unsponsored lite account may upgrade the account to a full account by:

• ensuring the account contains at least the Full Account Reserve (at time of writing 20 XRP)
• creating and successfully submitting an AccountSet transaction that clears the asfLiteAccount flag.

Downgrading¶

The owner of a full account may opt to downgrade their account to a lite account by:

• creating and successfully submitting an AccountSet transaction that sets the asfLiteAccount flag. This action frees up the difference between the full Account Reserve and the lite Account Reserve.

Deletion of Lite Accounts¶

The owner of a lite account may delete their account subject to certain conditions:

Scenario 1: Send all to Sponsor¶

If the lite account is sponsored then the owner of the lite account may:

• create and successfully submit an AccountDelete transaction, which
• specifies the account sponsor as the Destination field

Scenario 2: Upgrade and Delete¶

If the lite account is sponsored then the owner of the lite account may upgrade their account to an unsponsored account. Once the lite account is unspsonsored, the user may proceed with a normal AccountDelete operation (with the proceeds going to any desired Destination).