The XRP Ledger Foundation has published a draft XRP Ledger Standard for “AMM Swappable Curves,” a proposed amendment that would extend the XRPL’s native automated market maker beyond its current constant-product design. The proposal, authored by Denis Angell and Roman Thpt, would introduce pool-level curve selection at creation time, with StableSwap and concentrated liquidity among the first supported models.
XRPL Foundation Proposes AMM v2 Swappable Curves
The draft standard, listed as an amendment requiring XLS-30 AMM, describes a “pluggable curve architecture” for XRPL’s decentralized exchange infrastructure. Under the proposal, pool creators would select an invariant function when a pool is created. The initial set includes ConstantProduct, ConcentratedLiquidity and StableSwap, while Weighted pools and fully programmable Smart AMMs are reserved for later specifications.
XRPL Foundation said in its X post that the new pool curves are intended to “increase capital efficiency and stabilize pricing for stablecoins, FX markets, RWAs and beyond on the XRPL DEX.” The GitHub draft frames the change as a response to limitations in the current XLS-30 AMM. “The current XLS-30 AMM implements a single invariant (constant product) with uniform liquidity. This is capital-inefficient for correlated pairs and inflexible for specialized markets. Capital efficiency gap: Constant product spreads liquidity uniformly across the entire price range, so the share active near the current price is small.”
The proposal would preserve existing XLS-30 behavior for current AMM pools by defaulting pools without a curve field to CurveType 0, or ConstantProduct. For new pools, the ledger key would include the curve type for non-zero curve types, allowing one pool per asset pair and curve type to coexist. The draft states: “For CurveType > 0, the curve type is included in the hash, producing a distinct keylet per curve type. This allows multiple pools per token pair — one for each curve type — enabling new curve deployments without affecting existing constant product pools.”
StableSwap and Concentrated Liquidity Target XRPL
The two main additions in the draft are CurveType 1, ConcentratedLiquidity, and CurveType 2, StableSwap. Concentrated liquidity would let liquidity providers specify price ranges using ticks, similar in broad design to Uniswap v3, while StableSwap would use a Curve Finance-style invariant optimized for assets that trade near parity. The draft identifies use cases including stablecoins, correlated assets, foreign exchange markets and tokenized real-world assets.
For concentrated liquidity, positions would be non-fungible ledger objects rather than standard fungible LP tokens. The proposal introduces new ledger entries for AMM positions and ticks, plus an AMMCollectFees transaction that allows LPs to collect accumulated trading fees without removing liquidity. The draft explains the design choice directly: “CL positions are financial instruments, not collectibles. If position transfer is needed in the future, a dedicated AMMPositionTransfer transaction is simpler than inheriting NFToken transfer semantics.”
StableSwap pools would use an amplification coefficient, with the draft specifying a supported range from 1 to 5,000. The proposal describes A=1 as degenerating to constant product, A=100 as offering about 100 times capital efficiency near peg, and A=5,000 as a nearly flat curve for tightly pegged assets. The amendment would be gated behind featureAMMCurves, with default-no voting behavior, and would require featureAMM and fixAMMv1_1 before activation.
The proposal also outlines how XRPL’s payment engine would interact with multiple AMM curves. BookStep would iterate across protocol-compiled curve types for a token pair and select the pool with the best spot price, while still presenting a single offer to the rest of the payment engine. The draft says this should be transparent to routing: “Because a token pair can have one pool per protocol-compiled curve type, BookStep iterates those pools and selects the one with the best spot price to generate its offer. This is transparent to the rest of the payment engine — BookStep still produces a single offer per step.”
A future Smart AMM system is separated into a planned companion amendment, CurveType 4, which would support WASM-based programmable pools, lifecycle hooks, dynamic fees and custom invariants. The draft argues for a phased rollout rather than jumping directly to programmable AMMs. “Why protocol-compiled curves first: Deterministic by construction — no WASM sandbox risks. Zero runtime overhead (native C++ vs. WASM interpretation). Uniswap v3/v4 data shows concentrated liquidity alone captures 60% of volume — protocol-compiled CL is the highest-ROI feature.”
The AMM Swappable Curves proposal remains a draft standard, not an activated XRPL feature. If adopted through the amendment process, it would mark a significant expansion of XRPL’s native AMM design by allowing different liquidity models to coexist for the same asset pair while preserving backward compatibility for existing XLS-30 pools. For now, the proposal sets out the technical path for StableSwap, concentrated liquidity and a later Smart AMM framework on the XRP Ledger.
AI Transparency Note: This article was prepared with the assistance of an AI system based on the sources listed and was reviewed, edited, and approved by a human editor before publication. All quotes, data points, and factual claims are intended to be grounded in the cited source material; however, errors cannot be ruled out entirely.