This beta release adds support for Automated Market Makers. For details, you can refer to CAP-38 for XDR changes and this document for detailed changes to the Horizon API. Install it via yarn upgrade stellar-sdk@beta.

Add

• Introduced a LiquidityPoolCallBuilder to make calls to a new endpoint:

  • /liquidity_pools[?reserves=...] - a collection of liquidity pools, optionally filtered by one or more assets (#682)
  • /liquidity_pools/:id - a specific liquidity pool (#687)

• Expanded the TransactionCallBuilder, OperationCallBuilder, and EffectsCallBuilders to apply to specific liquidity pools (#689). This corresponds to the following new endpoints:

  • /liquidity_pools/:id/transactions
  • /liquidity_pools/:id/operations
  • /liquidity_pools/:id/effects

• Expanded the TradesCallBuilder to support fetching liquidity pool trades and accepts a new trade_type filter (#685):

  • /trades?trade_type={orderbook,liquidity_pools}
  • A liquidity pool trade contains the following fields:
    • liquidity_pool_fee_bp: LP fee expressed in basis points, and either
    • base_liquidity_pool_id or counter_liquidity_pool_id

• Added new effects related to liquidity pools (#690):

  • DepositLiquidityEffect
  • WithdrawLiquidityEffect
  • LiquidityPoolTradeEffect
  • LiquidityPoolCreatedEffect
  • LiquidityPoolRemovedEffect
  • LiquidityPoolRevokedEffect

• Added new responses related to liquidity pool operations (#692):

  • DepositLiquidityOperationResponse
  • WithdrawLiquidityOperationResponse

Updates

• Updated the underlying stellar-base library to v6.0.1 to include CAP-38 changes (#681).

• Updated various developer dependencies to secure versions (#671).

• Updated AccountResponse to include liquidity pool shares in its balances field (#688).

• Updated AccountCallBuilder to allow filtering based on participation in a certain liquidity pool (#688), corresponding to the following new filter:

  • /accounts?reserves=[...list of assets...]

• Updated RevokeSponsorshipOperationResponse to contain an optional attribute trustline_liquidity_pool_id, for when a liquidity pool trustline is revoked (#690).

Breaking changes

• A TradeRecord can now correspond to two different types of trades and has changed (#685):

  • Orderbook (the existing structure)
    • counter_offer_id and base_offer_id only show up in these records
    • the redundant offer_id field was removed; it matches base_offer_id
  • LiquidityPool (new)
    • base_account xor counter_account will appear in these records
  • price fields changed from numbers to strings
  • The links to base and counter can now point to either an account or a liquidity pool

• An account's balances array can now include a new type (#688):

  • asset_type can now be liquidity_pool_shares
  • The following fields are not included in pool share balances:
    • buying_liabilities
    • selling_liabilities
    • asset_code
    • asset_issue

• The ChangeTrustOperationResponse has changed (#688, #692):

  • asset_type can now be liquidity_pool_shares
  • asset_code, asset_issuer, and trustee are now optional
  • liquidity_pool_id is a new optional field

• The trustline effects (TrustlineCreated, TrustlineUpdated, TrustlineRevoked) have changed (#690):

  • the asset type can now be liquidity_pool_shares
  • they can optionally include a liquidity_pool_id

• Trustline sponsorship effects (TrustlineSponsorshipCreated, TrustlineSponsorshipUpdated, TrustlineSponsorshipRemoved) have been updated (#690):

  • the asset field is now optional, and is replaced by
  • the liquidity_pool_id field for liquidity pools