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Swap Pairs

Overview​

Astroport supports various pool types:

Depending on your use-cases and needs as well as the types of assets you want to integrate, one of these pools will be better than the other. To learn more about Astroport pools, visit here.

astroport-core also contains more specialised pool contracts that share the same pool interface: a transmuter (pair_transmuter, constant sum for 1:1 assets with no fee or slippage), a concentrated pool with an orderbook integration (pair_concentrated_duality, Neutron), pools with sale taxes (pair_xyk_sale_tax, pair_concentrated_sale_tax) and the one-way ASTRO converter pools (pair_astro_converter). Pools are created through the factory, which keeps the list of pool types it can create and their fees.

Exit-Only Pools​

Six Neutron pools that were drained in the 2026-09-22 incident now run astroport-pair-exit-only 1.0.0. They were refilled with the returned assets and only allow balanced withdrawals: no swaps and no deposits. LPs withdraw with withdraw_liquidity as usual. Routers and aggregators should not route through them; their simulation queries return an error.

Liquidity Providers​

A user can provide liquidity to a pool by calling provide_liquidity. Users can also withdraw liquidity by calling withdraw_liquidity.

NOTE

Native assets are attached to provide_liquidity as funds. For CW20 assets, a user must first allow the pool contract to take the tokens from their wallet.

Whenever liquidity is deposited into a pool, special tokens known as "liquidity tokens" are minted to the provider's address, in proportion to how much liquidity they contributed to the pool. Pools created by current factories use a tokenfactory LP denom (factory/<pool address>/astroport/share); older pools use a CW20 LP token. These tokens are a representation of a liquidity provider's contribution to a pool. Whenever a trade occurs, the LP part of the fee stays in the pool and accrues pro rata to all LPs at the moment of the trade. To receive the underlying liquidity back plus accrued LP fees, LPs must burn their liquidity tokens with withdraw_liquidity. Withdrawals are balanced: an LP receives its share of every pool asset.

LP tokens can be staked in the Incentives contract to earn external incentives, either afterwards or at deposit time with auto_stake. Astroport no longer pays ASTRO emissions to pools.

When providing liquidity from a smart contract, the most important thing to keep in mind is that the amount of tokens deposited into a pool and the amount of tokens withdrawn later from the pool will most likely not be the same (even if stableswap encourages a constant 1:1 ratio between all assets in the pool). In the case of PCL and constant product pools, as token prices in the pool change, so do the respective token amounts that a LP can withdraw.

Slippage Tolerance for Providing Liquidity​

If an LP specifies a slippage tolerance when they provide liquidity, the pool contract makes sure that the transaction goes through only if the pool price does not change more than tolerance. min_lp_to_receive adds a floor on the LP tokens minted.

As an example, let's say someone LPs in a passive concentrated liquidity pool and specifies a 1% slippage tolerance. The user LPs 200 USDC and 1 ASSET. A similar example could be set with a stableswap pool and a pair of 200 USDC and 200 ASSET.

With a 1% slippage tolerance, amountUSDCMin (the minimum amount of USDC to LP) should be set to 198 USDC, and amountASSETMin (the minimum amount of ASSET to LP) should be set to .99 ASSET. This means that, in a worst case scenario, liquidity will be added at a pool rate of 198 USDC/1 ASSET or 202.02 USDC/1 ASSET (200 USDC + .99 ASSET). If the contract cannot add liquidity within these bounds (because the pool ratio changed more than the tolerance), the transaction will revert.

Traders​

Slippage Tolerance for Swaps​

Astroport has two options to protect traders against slippage during swaps:

  1. Providing max_spread - The spread is calculated as the difference between the ask amount (using the constant pool price) before and after the swap operation. Once max_spread is set, it will be compared against the actual swap spread. In case the swap spread exceeds the provided max limit, the swap will fail.

Note that the spread is calculated before commission deduction in order to properly represent the pool's ratio change.

  1. Providing max_spread + belief_price - If belief_price is provided in combination with max_spread, the pool will check the difference between the return amount (using belief_price) and the real pool price.
NOTE

Astroport has the default value for the spread set to 0.5% and the max allowed spread set to 50%.

For multi-hop swaps, router 2.0 disables each pool's spread check and enforces a single minimum_receive on the final output instead.