flat-fee.md

Flat Fee Pricing Program

Pricing program that levies flat fees.

Fees are deducted by taking a set portion from the calculated resulting value depending on the token type.

Accounts

ProgramState

The program state singleton is located at PDA ["state"].

Schema

The struct is bytemuck/zero_copy. Explicit manual padding is required, but not shown.

Name	Value	Type
manager	The manager authorized to update the fee accounts for each LST and LP	Pubkey
lp_withdrawal_fee_bps	Fee in bips to impose when redeeming LP token for LST	u16

FeeAccount

The Account that describes the fee for each pricing type. The FeeAccount is located at PDA ["fee", token_mint].

Schema

The struct is bytemuck/zero_copy. Explicit manual padding is required, but not shown.

NOTE: a negative fee value means incentivization for given route

Name	Value	Type
bump	This FeeAccount's PDA bump	u8
input_fee_bps	Fee in bips to impose when the token type is used as input	i16
output_fee_bps	Fee in bips to impose when the token type is used as output	i16

Instructions

Common Interface

PriceExactIn

Given an input LST amount and its SOL value, calculate the output SOL value by:

• calculate total fee in bips by adding fee_acc_input.input_fee_bps and fee_acc_output.output_fee_bps
• calculate output LST's sol value after imposing fee by using the calculated fee and the given sol_value of input lst

Data

Name	Value	Type
discriminant	0	u8
amount	amount of the input LST	u64
sol_value	SOL value of amount input LST	u64

Accounts

Account	Description	Read/Write (R/W)	Signer (Y/N)
input_lst_mint	Mint of the input LST	R	N
output_lst_mint	Mint of the output LST	R	N
input_fee_acc	FeeAccount PDA for the input LST	R	N
output_fee_acc	FeeAccount PDA for the output LST	R	N

Return Data

Name	Value	Type
result	The calculated output SOL value	u64

Procedure

PriceExactOut

Given an output LST amount and its SOL value, calculate the input SOL value by:

• calculate total fee in bips by adding fee_acc.input_fee_bps and fee_acc.output_fee_bps
• calculate input LST's sol value using given sol_value of output lst assuming that the calculated fee was imposed to resulting input lst's SOL value

Data

Name	Value	Type
discriminant	1	u8
amount	amount of the output LST	u64
sol_value	SOL value of amount output LST	u64

Return Data

Name	Value	Type
result	The calculated input SOL value	u64

Accounts

Account	Description	Read/Write (R/W)	Signer (Y/N)
input_lst_mint	Mint of the input LST	R	N
output_lst_mint	Mint of the output LST	R	N
input_fee_acc	FeeAccount PDA for the input LST	R	N
output_fee_acc	FeeAccount PDA for the output LST	R	N

Procedure

PriceLpTokensToMint

Given an input LST amount and its SOL value, calculate the SOL value of the LP tokens to mint.

Data

Name	Value	Type
discriminant	2	u8
amount	amount of the input LST	u64
sol_value	SOL value of amount input LST	u64

Return Data

Name	Value	Type
result	The calculated SOL value of LP tokens to mint	u64

Accounts

Account	Description	Read/Write (R/W)	Signer (Y/N)
input_lst_mint	Mint of the input LST	R	N

Procedure

PriceLpTokensToRedeem

Given an input LP token amount and its SOL value, calculate the SOL value of the LST to redeem.

Data

Name	Value	Type
discriminant	3	u8
amount	amount of the input LP	u64
sol_value	SOL value of amount input LP	u64

Return Data

Name	Value	Type
result	The calculated SOL value of the LST to redeem	u64

Accounts

Account	Description	Read/Write (R/W)	Signer (Y/N)
output_lst_mint	Mint of the output LST	R	N
state	Program state PDA	R	N

Procedure

Regardless of how the price is calculated, the pricing program should guarantee that this instruction levies sufficient fees on the redeem amount such that LPs cannot extract value from the pool by adding liquidity right before the epoch boundary and then removing liquidity right after the SOL value increase from staking rewards.

Management Instructions

Only the current manager is authorized to execute.

Initialize

Permissionlessly initialize the program state. Can only be called once and sets manager to a hardcoded init manager.

Data

Name	Value	Type
discriminant	255	u8

Accounts

Account	Description	Read/Write (R/W)	Signer (Y/N)
payer	Account paying for ProgramState's rent	W	Y
state	Program state PDA	W	N
system_program	System program	R	N

SetManager

Update the manager authority of the pricing program.

Data

Name	Value	Type
discriminant	254	u8

Accounts

Account	Description	Read/Write (R/W)	Signer (Y/N)
current_manager	The current program manager	R	Y
new_manager	The new program manager to set to	R	N
state	Program state PDA	W	N

AddLst

Enable an LST to be supported by the program

Data

Name	Value	Type
discriminant	253	u8
input_fee_bps	fee in bips to impose when the token type is used as input	i16
output_fee_bps	fee in bips to impose when the token type is used as output	i16

Accounts

Account	Description	Read/Write (R/W)	Signer (Y/N)
manager	The program manager	R	Y
payer	Account paying for FeeAccount's rent	W	Y
fee_acc	FeeAccount PDA to create	W	N
lst_mint	Mint of the LST	R	N
state	Program state PDA	R	N
system_program	System program	R	N

RemoveLst

Disable an added LST

Data

Name	Value	Type
discriminant	252	u8

Accounts

Account	Description	Read/Write (R/W)	Signer (Y/N)
manager	The program manager	R	Y
refund_rent_to	Account to refund SOL rent to	R	N
fee_acc	FeeAccount PDA to modify	W	N
lst_mint	Mint of the LST	R	N
state	Program state PDA	R	N

SetLstFee

Update the fees for given type of pricing action.

Data

Name	Value	Type
discriminant	251	u8
input_fee_bps	fee in bips to impose when the token type is used as input	i16
output_fee_bps	fee in bips to impose when the token type is used as output	i16

Accounts

Account	Description	Read/Write (R/W)	Signer (Y/N)
manager	The program manager	R	Y
fee_acc	FeeAccount PDA to modify	W	N
state	Program state PDA	R	N

SetLpWithdrawalFee

Update the fees imposed for redeeming LP token for LST

Data

Name	Value	Type
discriminant	250	u8
lp_withdrawal_fee_bps	fee in bips to impose when redeeming LP token for LST	u16

Accounts

Account	Description	Read/Write (R/W)	Signer (Y/N)
manager	The program manager	R	Y
state	Program state PDA	W	N