The following is a comprehensive list of all known amendments and their status on the production XRP Ledger:
Note: In many cases, an incomplete version of the code for an amendment is present in previous versions of the software. The "Introduced" version in the table above is the first stable version. The value "TBD" indicates that the amendment is not yet considered stable.
Introduces "Checks" to the XRP Ledger. Checks work similarly to personal paper checks. The sender signs a transaction to create a Check for a specific maximum amount and destination. Later, the destination can cash the Check to receive up to the specified amount. The actual movement of money only occurs when the Check is cashed, so cashing the Check may fail depending on the sender's current balance and the available liquidity. If cashing the Check fails, the Check object remains in the ledger so it may be successfully cashed later.
The sender or the receiver can cancel a Check at any time before it is cashed. A Check can also have an expiration time, after which it cannot be cashed, and anyone can cancel it.
Introduces three new transaction types: CheckCreate, CheckCancel, and CheckCash, and a new ledger object type, Check. Adds a new transaction result code,
tecEXPIRED, which occurs when trying to create a Check whose expiration time is in the past.
This amendment also changes the OfferCreate transaction to return
tecEXPIRED when trying to create an Offer whose expiration time is in the past. Without this amendment, an OfferCreate whose expiration time is in the past returns
tesSUCCESS but does not create or execute an Offer.
Although this amendment is enabled, it has no effect unless the SusPay amendment is also enabled. Ripple does not expect SusPay to become enabled. Instead, Ripple plans to incorporate crypto-conditions in the Escrow amendment.
Implements several types of crypto-conditions from the official crypto-conditions specification for use in EscrowCreate and EscrowFinish transactions. Without this amendment, only the PREIMAGE-SHA-256 type is supported.
Caution: This amendment is still in development. The version from
rippled v0.60.0 to present does not implement the full functionality.
Adds a new account flag,
DepositAuth, which lets an account strictly reject any incoming money from transactions sent by other accounts. Businesses can use this flag to comply with strict regulations that require due diligence before receiving money from any source.
When an account enables this flag, Payment transactions fail if the account is the destination, regardless of whether the Payment would have delivered XRP or an issued currency. EscrowFinish and PaymentChannelClaim transactions fail if the account is the destination unless the destination account itself sends those transactions. If the Checks amendment is enabled, the account can receive XRP or issued currencies by sending CheckCash transactions.
As an exception, accounts with
DepositAuth enabled can receive Payment transactions for small amounts of XRP (equal or less than the minimum account reserve) if their current XRP balance is below the account reserve.
Also fixes a bug in the EscrowCreate and PaymentChannelCreate transactions where they mistakenly enforced the DisallowXRP flag, which is meant to be a non-binding advisory flag. (By not enforcing DisallowXRP in the ledger itself an account can still receive the necessary XRP to meet its account reserve and pay transaction costs.)
Provides users of deposit authorization with a way to preauthorize specific senders so those senders are allowed to send payments directly.
Adds a new transaction type, DepositPreauth for adding or removing preauthorization, and a DepositPreauth ledger object type for tracking preauthorizations from one account to another. Adds a JSON-RPC command,
deposit_authorized, to query whether an account is authorized to send payments directly to another.
Also changes the behavior of cross-currency Payments from an account to itself when that account requires deposit authorization. Without this amendment, those payments always fail with the code tecNO_PERMISSION. With this amendment, those payments succeed as they would with Deposit Authorization disabled.
Adds sanity checks to transaction processing to ensure that certain conditions are always met. This provides an extra, independent layer of protection against bugs in transaction processing that could otherwise cause exploits and vulnerabilities in the XRP Ledger. Ripple expects to add more invariant checks in future versions of
rippled without additional amendments.
Introduces two new transaction error codes,
tefINVARIANT_FAILED. Changes transaction processing to add the new checks.
Examples of invariant checks:
- The total amount of XRP destroyed by a transaction must match the transaction cost exactly.
- XRP cannot be created.
AccountRootobjects in the ledger cannot be deleted. (See also: Permanence of Accounts.)
- An object in the ledger cannot change its type. (The
LedgerEntryTypefield is immutable.)
- There cannot be a trust line for XRP.
Provides "suspended payments" for XRP for escrow within the XRP Ledger, including support for Interledger Protocol Crypto-Conditions. Creates a new ledger object type for suspended payments and new transaction types to create, execute, and cancel suspended payments.
Changes the way the transaction cost applies to proposed transactions. Modifies the consensus process to prioritize transactions that pay a higher transaction cost.
This amendment introduces a fixed-size transaction queue for transactions that were not able to be included in the previous consensus round. If the
rippled servers in the consensus network are under heavy load, they queue the transactions with the lowest transaction cost for later ledgers. Each consensus round prioritizes transactions from the queue with the largest transaction cost (
Fee value), and includes as many transactions as the consensus network can process. If the transaction queue is full, transactions drop from the queue entirely, starting with the ones that have the lowest transaction cost.
While the consensus network is under heavy load, legitimate users can pay a higher transaction cost to make sure their transactions get processed. The situation persists until the entire backlog of cheap transactions is processed or discarded.
A transaction remains in the queue until one of the following happens:
- It gets applied to a validated ledger (regardless of success or failure)
- It becomes invalid (for example, the
LastLedgerSequencecauses it to expire)
- It gets dropped because there are too many transactions in the queue with a higher transaction cost.
Correctly implements a limit on transfer fees to a 100% fee, represented by a maximum
TransferRate value of
2000000000. (A 100% fee in this case means you must send 2 units of the issued currency for every 1 unit you want to deliver.) Without the amendment, the effective limit is a
TransferRate value of 232-1, for approximately a 329% fee.
With this amendment enabled, an AccountSet transaction that attempts to set
TransferRate higher than
2000000000 fails with the result code
temBAD_TRANSFER_RATE. Any existing
TransferRate which was set to a higher value under the previous rules continues to apply at the higher rate.
Fixes a minor bug in transaction processing that causes some payments to fail when they should be valid. Specifically, during payment processing, some payment steps that are expected to produce a certain amount of currency may produce a microscopically different amount, due to a loss of precision related to floating-point number representation. When this occurs, those payments fail because they cannot deliver the exact amount intended. The fix1368 amendment corrects transaction processing so payments can no longer fail in this manner.
Fixes a minor bug in transaction processing that causes failures when trying to prepare certain payment paths for processing. As a result, payments could not use certain paths that should have been valid but were invalidly prepared. Without this amendment, those payments are forced to use less-preferable paths or may even fail.
The fix1373 amendment corrects the issue so that the paths are properly prepared and payments can use them. It also disables some inappropriate paths that are currently allowed, including paths whose steps include conflicting fields and paths that loop through the same object more than once.
Fixes a bug in transaction processing that causes some invalid PaymentChannelClaim transactions to fail with the wrong error code. Without this amendment, the transactions have a
tec-class result code despite not being included in a ledger and therefore not paying the transaction cost.
With this amendment, the transactions fail with a more appropriate result code,
Fixes a bug that resulted in transaction processing not using new
STAmountCalcSwitchovers code when the
FeeEscalation amendment is enabled.
With this amendment, the new
STAmountCalcSwitchovers code applies, which may cause slight changes to transaction processing due to calculation differences. Amounts may be rounded differently and offers may be executed in a different order as a result.
Changes how Payment transactions consume offers to remove a minor difference in how payment processing and offer processing consume liquidity. (Also affects how OfferCreate transactions are processed if FlowCross is enabled.)
Without the amendment, payment processing gives up on using particular order books if the transaction would consume over 2000 offers at the same exchange rate. In this case, the payment does not use the liquidity from those offers, and does not consider that order book's remaining liquidity when attempting to complete the payment.
With this amendment, if any transaction processes over 1000 offers at the same exchange rate, the transaction consumes the liquidity from the first 1000 offers, then does not consider that order book's remaining liquidity when attempting to complete the payment.
In both cases, transaction processing can still complete by using liquidity from other paths or exchange rates.
Adds tracking by destination account to escrows. Without this amendment, pending escrows are only tracked by sender. This amendment makes it possible to look up pending escrows by the destination address using the account_objects method, excluding any pending escrows that were created before this amendment became enabled. This amendment also makes EscrowCreate transactions appear in the destination's transaction history, as viewed with the account_tx method.
With this amendment, new escrows are added to the owner directories of both the sender and receiver. This amendment also adds a new
DestinationNode field to Escrow ledger objects, indicating which page of the destination's owner directory contains the escrow.
Fixes a bug where validators could build consensus ledgers with different timestamps, potentially delaying the process of declaring validated ledgers. The circumstances for this to occur require precise timing, so validators are unlikely to encounter this bug outside of controlled test conditions.
This amendment changes how validators negotiate the close time of the consensus ledger so that they cannot reach a consensus on ledger contents but build ledger versions with different timestamps.
Enforces reserved flag ranges on some transaction types that did not correctly enforce them already. Transactions of the affected types are now considered invalid if they enable undefined or unknown flags, or flags from the reserved range. (Transactions unaffected by this change already correctly enforce the same rules.)
Without this amendment, transactions of certain types are considered valid even when they have undefined or reserved flags enabled.
The affected transaction types are:
- Escrow transactions: EscrowCancel, EscrowCreate, and EscrowFinish
- Payment Channel transactions: PaymentChannelClaim, PaymentChannelCreate, and PaymentChannelFund
Changes Escrow to fix the following issues:
- Changes the EscrowCreate transaction to require the
FinishAfterfield (or both). Escrows with neither
FinishAfterthat were created before this amendment can be finished by anyone at any time before their
- Fixes a flaw that incorrectly prevents time-based Escrows from being finished in some circumstances.
Adds delivered amount to metadata for CheckCash transactions cashed for a flexible amount. (Has no effect unless the Checks amendment is enabled.)
With this amendment enabled, transaction processing adds a
DeliveredAmount field to the metadata of CheckCash transactions for a variable amount (using the
DeliverMin field). This change is written to the ledger data, resulting in a different ledger hash than would result from processing the transaction without this amendment. It does not affect the actual amounts delivered. Additionally, with this amendment enabled, the tx method and account_tx method return a
delivered_amount field for CheckCash transactions. (The
delivered_amount field is calculated when you look up a transaction, and is not part of the data that is written to the ledger.)
The fix1623 amendment has no effect on CheckCash transactions for a fixed amount (using the
Amount field) or any other transaction types.
rippled 1.0.0, if the Checks amendment is enabled before the fix1623 amendment, the
delivered_amount may display as "0" for variable-amount CheckCash transactions from before this amendment was enabled, even if the transaction delivered a nonzero amount. Ripple plans to enable fix1623 at the same time as the Checks amendment on the production network, but this situation may be possible on parallel networks.
Replaces the payment processing engine with a more robust and efficient rewrite called the Flow engine. The new version of the payment processing engine is intended to follow the same rules as the old one, but occasionally produces different results due to floating point rounding. This Amendment supersedes the FlowV2 amendment.
The Flow Engine also makes it easier to improve and expand the payment engine with further Amendments.
Streamlines the offer crossing logic in the XRP Ledger's decentralized exchange. Uses the updated code from the Flow amendment to power offer crossing, so OfferCreate transactions and Payment transactions share more code. This has subtle differences in how offers are processed:
- Rounding is slightly different in some cases.
- Due to differences in rounding, some combinations of offers may be ranked higher or lower than by the old logic, and taken preferentially.
- The new logic may delete more or fewer offers than the old logic. (This includes cases caused by differences in rounding and offers that were incorrectly removed as unfunded by the old logic.)
Introduces multi-signing as a way to authorize transactions. Creates the
SignerList ledger object type and the
SignerListSet transaction type. Adds the optional
Signers field to all transaction types. Modifies some transaction result codes.
This amendment allows addresses to have a list of signers who can authorize transactions from that address in a multi-signature. The list has a quorum and 1 to 8 weighted signers. This allows various configurations, such as "any 3-of-5" or "signature from A plus any other two signatures."
Signers can be funded or unfunded addresses. Funded addresses in a signer list can sign using a regular key (if defined) or master key (unless disabled). Unfunded addresses can sign with a master key. Multi-signed transactions have the same permissions as transactions signed with a regular key.
An address with a SignerList can disable the master key even if a regular key is not defined. An address with a SignerList can also remove a regular key even if the master key is disabled. The
tecMASTER_DISABLED transaction result code is renamed
tecNO_REGULAR_KEY transaction result is retired and replaced with
tecNO_ALTERNATIVE_KEY. Additionally, this amendment adds the following new transaction result codes:
Fixes an inconsistency in the way transfer fees are calculated between OfferCreate and Payment transaction types. Without this amendment, the holder of the issuances pays the transfer fee if an offer is executed in offer placement, but the initial sender of a transaction pays the transfer fees for offers that are executed as part of payment processing. With this amendment, the holder of the issuances always pays the transfer fee, regardless of whether the offer is executed as part of a Payment or an OfferCreate transaction. Offer processing outside of payments is unaffected.
This Amendment requires the Flow Amendment to be enabled.
Note: An incomplete version of this amendment was introduced in v0.33.0 and removed in v0.80.0. (It was never enabled.) Ripple plans to re-add the amendment when the code is stable enough.
Creates "Payment Channels" for XRP. Payment channels are a tool for facilitating repeated, unidirectional payments or temporary credit between two parties. Ripple expects this feature to be useful for the Interledger Protocol. One party creates a Payment Channel and sets aside some XRP in that channel for a predetermined expiration. Then, through off-ledger secure communications, the sender can send "Claim" messages to the receiver. The receiver can redeem the Claim messages before the expiration, or choose not to in case the payment is not needed. The receiver can verify Claims individually without actually distributing them to the network and waiting for the consensus process to redeem them, then redeem the batched content of many small Claims later, as long as it is within the expiration.
Creates three new transaction types: PaymentChannelCreate, PaymentChannelClaim, and PaymentChannelFund. Creates a new ledger object type, PayChannel. Defines an off-ledger data structure called a
Claim, used in the ChannelClaim transaction. Creates new
rippled API methods:
channel_authorize (creates a signed Claim),
channel_verify (verifies a signed Claim), and
account_channels (lists Channels associated with an account).
For more information, see the Payment Channels Tutorial.
Changes the hash tree structure that
rippled uses to represent a ledger. The new structure is more compact and efficient than the previous version. This affects how ledger hashes are calculated, but has no other user-facing consequences.
When this amendment is activated, the XRP Ledger will undergo a brief scheduled unavailability while the network calculates the changes to the hash tree structure.
Sorts the entries in DirectoryNode ledger objects and fixes a bug that occasionally caused pages of owner directories not to be deleted when they should have been.
Warning: Older versions of
rippled that do not know about this amendment may crash when they encounter a DirectoryNode sorted by the new rules. To avoid this problem, upgrade to
rippled version 0.80.0 or later.
Introduces Tickets as a way to reserve a transaction sequence number for later execution. Creates the
Ticket ledger object type and the transaction types
Caution: This amendment is still in development.
Changes the way Offers are ranked in order books, so that currency issuers can configure how many significant digits are taken into account when ranking Offers by exchange rate. With this amendment, the exchange rates of Offers are rounded to the configured number of significant digits, so that more Offers have the same exact exchange rate. The intent of this change is to require a meaningful improvement in price to outrank a previous Offer. If used by major issuers, this should reduce the incentive to spam the ledger with Offers that are only a tiny fraction of a percentage point better than existing offers. It may also increase the efficiency of order book storage in the ledger, because Offers can be grouped into fewer exchange rates.
TickSize field to accounts, which can be set with the AccountSet transaction type. If a currency issuer sets the
TickSize field, the XRP Ledger truncates the exchange rate (ratio of funds in to funds out) of Offers to trade the issuer's currency, and adjusts the amounts of the Offer to match the truncated exchange rate. If only one currency in the trade has a
TickSize set, that number of significant digits applies. When trading two currencies that have different
TickSize values, whichever
TickSize indicates the fewest significant digits applies. XRP does not have a
Allows pre-authorization of accounting relationships (zero-balance trust lines) when using Authorized Trust Lines.
With this amendment enabled, a
TrustSet transaction with
tfSetfAuth enabled can create a new
RippleState ledger object even if it keeps all the other values of the
RippleState node in their default state. The new
RippleState node has the
lsfHighAuth flag enabled, depending on whether the sender of the transaction is considered the low node or the high node. The sender of the transaction must have already enabled
lsfRequireAuth by sending an AccountSet transaction with the asfRequireAuth flag enabled.