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Documentation Index

Fetch the complete documentation index at: https://docs.raydium.io/llms.txt

Use this file to discover all available pages before exploring further.

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The fee model

Stable AMM uses the same fee structure as AMM v4. There is only one fee tier per pool (set at initialization); pools cannot be reconfigured into higher tiers.
FieldDefaultMeaning
swap_fee_numerator / swap_fee_denominator25 / 10_000Gross trade fee: 0.25% of input volume.
trade_fee_numerator / trade_fee_denominator25 / 10_000Same 0.25%, used by OpenBook integration for order pricing.
pnl_numerator / pnl_denominator12 / 100Protocol’s share of the fee: 12% — i.e., 0.25% × 12% = 0.03% of volume.
min_separate_numerator / min_separate_denominator4 / 10_000Internal rounding floor.
There is no fund-fee and no creator-fee line — these are post-AMM v4 inventions (CPMM/CLMM). Stable AMM predates that convention.

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How the split is computed

On each swap: 
gross_fee = ceil(amount_in * (swap_fee_numerator / swap_fee_denominator))    // e.g., 0.25% of amount_in
pnl_portion = gross_fee * (pnl_numerator / pnl_denominator)                  // 12% of gross_fee
lp_portion = gross_fee − pnl_portion                                          // 88% of gross_fee
  • lp_portion stays in the vault, inflates k, and benefits LPs on redemption.
  • pnl_portion increments AmmInfo.out_put.need_take_pnl_coin or need_take_pnl_pc (depending on the input token) and is swept by WithdrawPnl.
Same invariant-preserving trick as CPMM: the PnL amount sits in the vault physically but is subtracted from the “effective reserves” used in the curve math, so removing it does not shift the price.

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PnL from OpenBook (same as AMM v4)

When the pool’s limit orders on OpenBook get filled, it can be on the taker side and earn or lose the market-maker/taker spread. These fills settle during MonitorStep and credit / debit the pool reserves. The program tracks them in out_put.total_pnl_{coin,pc} counters for analytics. This OpenBook PnL is distinct from the 0.03% protocol fee. It inflates the pool reserves and benefits LPs and protocol proportionally. Operational coupling to OpenBook is a reason why CPMM (order-book-independent) is now the default for new pools.

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Collection

The Raydium multisig (or whoever controls amm_admin) calls WithdrawPnl to sweep:
  1. Settles any pending OpenBook fills first (via internal crank logic).
  2. Transfers need_take_pnl_coin and need_take_pnl_pc from vaults to admin-designated accounts.
  3. Zeroes the counters.
The operation does not move the curve. LPs see no price change.

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LP fee redemption

No dedicated “collect fees” instruction. LP fees accumulate in vaults, inflating the reserves. LPs realize them by burning LP via Withdraw. The value of an LP token grows as reserves grow.

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Visualization: where $1,000 of volume goes

On a USDC-heavy Swap of $1,000 against a default-parameter Stable pool: 
Gross trade fee (0.25%):     $2.50
  LP share   (0.22%):         $2.20  → stays in pool, raises k
  PnL share  (0.03%):         $0.30  → need_take_pnl_pc, swept by WithdrawPnl
User receives (minus curve):  $997.50
Compare to AMM v4 (identical) and CPMM (0.25% tier, no creator fee): CPMM gives LPs $2.10, protocol $0.30, fund $0.10.

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Comparison table

Stable AMMAMM v4CPMM index=0
Trade fee0.25%0.25%0.25%
LP0.22%0.22%0.21%
Protocol0.03%0.03%0.03%
FundNoneNone0.01%
CreatorNoneNone0 by default
Full matrix: reference/fee-comparison.

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Integrator notes

  • Quoting: Always read AmmInfo from the chain; do not hardcode fees. In principle SetParams can change them, though the multisig has not changed the defaults.
  • Curve vs. fees: The 0.25% fee is independent of whether the curve is a formula (x·y=k in AMM v4) or a lookup table (Stable). Both apply the same 0.25% to the input amount.
  • No rewards: Stable pools do not support on-pool reward emissions. Ecosystem farms (Farm v3/v5/v6) handle staking elsewhere.

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Where to go next

Sources:
  • raydium-stable/program/src/state.rs (Fees struct)
  • On-chain AmmInfo.fees fields on live mainnet pools