Pool Manager

Liquidity pools, swaps, and routing for MANTRA DEX (MANTRA Swap)

The Pool Manager is a contract that handles liquidity pools in the MANTRA DEX. It facilitates the creation and management of different pool types, liquidity provision, swaps, and multi-hop operations across pools.

Pool creation is permissionless (a fee is required to prevent spam). Multiple pools can exist for the same asset pair, each with a unique identifier.

Pool types

There are two pool types: constant product (XYK) and stableswap.

XYK Pool

The XYK pool uses a constant product invariant:

$$XY = k$$

Where X and Y are the reserves for each token, and k is constant.

$$XY = k = (X + \Delta x)(Y - \Delta y)$$

To determine the ask asset amount (\Delta y) given the offered asset (\Delta x):

$$\Delta y = \\frac{Y\\Delta x}{X + \\Delta x}$$

The spread between executed and expected trade is:

$$spread = (Y\\Delta x/X) - (Y\\Delta x/(X + \\Delta x))$$

Stableswap

Implements the StableSwap curve described by Curve: https://curve.fi/files/stableswap-paper.pdf.

Supports 2–4 assets and is designed for low slippage stable-asset trading.

Instantiate

{
  "fee_collector_addr": "mantra1...",
  "farm_manager_addr": "mantra1...",
  "pool_creation_fee": {
    "denom": "amantra",
    "amount": "1000000000000000000000"
  }
}

Key	Type	Description
fee_collector_addr	String	Fee collector contract address.
farm_manager_addr	String	Farm manager contract address.
pool_creation_fee	Coin	Cost to create a pool.

ExecuteMsg

CreatePool

Creates a new pool with assets, decimals, fees, pool type, and identifier.

Pool identifiers:

• Auto-assigned pools get prefix p. (e.g. p.1)
• Custom identifiers get prefix o. (e.g. o.my_pool)

Pool identifiers are immutable on-chain strings. Existing pools created before the rebranding may still reference legacy denom names (e.g. uom) in their identifiers.

XYK example

{
  "create_pool": {
    "asset_denoms": ["amantra", "uusdc"],
    "asset_decimals": [18, 6],
    "pool_fees": {
      "protocol_fee": { "share": "0.001" },
      "swap_fee": { "share": "0.002" },
      "burn_fee": { "share": "0" },
      "extra_fees": [{ "share": "0.001" }]
    },
    "pool_type": "constant_product",
    "pool_identifier": "amantra.uusdy.pool"
  }
}

Stableswap example

{
  "create_pool": {
    "asset_denoms": ["uusdt", "uusdc"],
    "asset_decimals": [6, 6],
    "pool_fees": {
      "protocol_fee": { "share": "0.0002" },
      "swap_fee": { "share": "0.0003" },
      "burn_fee": { "share": "0" },
      "extra_fees": []
    },
    "pool_type": { "stable_swap": { "amp": 85 } },
    "pool_identifier": "uusdt.uusdc.pool"
  }
}

Key	Type	Description
asset_denoms	Vec<String>	Asset denoms.
asset_decimals	Vec<u8>	Decimals for each denom (same order as asset_denoms).
pool_fees	PoolFee	Pool fees.
pool_type	PoolType	Constant product or stableswap.
pool_identifier	Option<String>	Pool identifier (optional).

ProvideLiquidity

Provides liquidity to a pool. If lock_position_identifier is set, LP tokens are locked in the farm manager for the specified duration; otherwise they are sent to the receiver.

It’s only possible to lock an LP position for the same user providing liquidity (not on behalf of another user).

{
  "provide_liquidity": {
    "slippage_tolerance": "0.01",
    "max_spread": "0.1",
    "receiver": "mantra1...",
    "pool_identifier": "amantra.uusdy.pool",
    "unlocking_duration": 2678400,
    "lock_position_identifier": "lp.lock.identifier"
  }
}

Key	Type	Description
slippage_tolerance	Option<Decimal>	Max acceptable slippage.
max_spread	Option<Decimal>	Max spread allowed.
receiver	Option<String>	Receiver of LP tokens.
pool_identifier	String	Pool identifier.
unlocking_duration	Option<u64>	Duration (seconds) for farm lock/unlock behavior.
lock_position_identifier	Option<String>	Position identifier to lock (if any).

Swap

Swaps an offer asset to an ask asset in a specific pool. Offer amount is provided in info.funds.

{
  "swap": {
    "ask_asset_denom": "uusdc",
    "belief_price": "0.5",
    "max_spread": "5000",
    "receiver": "mantra1...",
    "pool_identifier": "amantra.uusdy.pool"
  }
}

Key	Type	Description
ask_asset_denom	String	Return asset denom.
belief_price	Option<Decimal>	Belief price.
max_spread	Option<Decimal>	Maximum spread.
receiver	Option<String>	Recipient (defaults to sender).
pool_identifier	String	Pool identifier.

WithdrawLiquidity

Withdraws liquidity from a pool. LP tokens must be sent with the transaction.

{
  "withdraw_liquidity": {
    "pool_identifier": "amantra.uusdy.pool"
  }
}

Key	Type	Description
pool_identifier	String	Pool identifier.

ExecuteSwapOperations

Executes multiple swap operations (multi-hop). Routes are computed off-chain.

{
  "execute_swap_operations": {
    "operations": [
      {
        "mantra_swap": {
          "token_in_denom": "uluna",
          "token_out_denom": "amantra",
          "pool_identifier": "uluna_amantra_pool"
        }
      },
      {
        "mantra_swap": {
          "token_in_denom": "amantra",
          "token_out_denom": "uusdc",
          "pool_identifier": "amantra.uusdy.pool"
        }
      }
    ],
    "minimum_receive": "1000000000000000000",
    "receiver": "mantra1...",
    "max_spread": "0.1"
  }
}

Key	Type	Description
operations	Vec<SwapOperation>	Operations in order.
minimum_receive	Option<Uint128>	Minimum amount received.
receiver	Option<String>	Final recipient.
max_spread	Option<Decimal>	Max spread per swap.

UpdateConfig

{
  "update_config": {
    "fee_collector_addr": "mantra1...",
    "farm_manager_addr": "mantra1...",
    "pool_creation_fee": { "denom": "amantra", "amount": "1000000000000000000000" },
    "feature_toggle": {
      "withdrawals_enabled": true,
      "deposits_enabled": true,
      "swaps_enabled": true
    }
  }
}

UpdateOwnership (::cw_ownable)

This is a cw_ownable message.

QueryMsg

Config

{ "config": {} }

AssetDecimals

{
  "asset_decimals": {
    "pool_identifier": "amantra-usdc-1",
    "denom": "amantra"
  }
}

Simulation

{
  "simulation": {
    "offer_asset": { "denom": "amantra", "amount": "1000000000000000000" },
    "ask_asset_denom": "uusdc",
    "pool_identifier": "amantra-usdc-1"
  }
}

ReverseSimulation

{
  "reverse_simulation": {
    "ask_asset": { "denom": "uusdc", "amount": "990000" },
    "offer_asset_denom": "amantra",
    "pool_identifier": "amantra-usdc-1"
  }
}

SimulateSwapOperations / ReverseSimulateSwapOperations

See legacy examples in _tmp_gitbook/mantra-smart-contracts/mantra-swap/pool-manager.md (ported here verbatim in structure).

Pools

{
  "pools": {
    "pool_identifier": "amantra-usdc-1",
    "start_after": null,
    "limit": 10
  }
}

Ownership (::cw_ownable)

This is a cw_ownable query.

MigrateMsg

{}