SolSoul Fee Model

SolSoul uses a two-fee structure designed for credible neutrality and long-term token-holder alignment.

Fee overview

Launch fee (0.03 SOL)

Paid once per token launch by the launcher. The fee is transferred to the Treasury PDA ([b"treasury"]).

Treasury mechanics

• The treasury is a PDA owned by the bonding-curve program with zero data (it only holds lamports).
• On create_token, if the treasury has zero lamports, it is created with LAUNCH_FEE_LAMPORTS lamports.
• If the treasury already exists (from a previous launch), the launch fee is transferred into it.
• There is no on-chain logic for spending treasury funds. Distribution is an off-chain operational concern.

Rationale

The flat 0.03 SOL fee is low enough to not discourage experimentation, but non-zero enough to prevent spam launches. At current SOL prices (~$150), this is approximately $4.50 per launch.

Lock fee (0.1% of buy SOL)

Deducted from every buy transaction before the net SOL enters the vault.

Lock mechanics

let lock_fee = sol_in * LOCK_FEE_BASIS_POINTS / BASIS_POINTS_DENOMINATOR;
// lock_fee = sol_in * 10 / 10_000 = sol_in * 0.001
let net_sol_in = sol_in - lock_fee;

1. lock_fee lamports are transferred from buyer to the Curve PDA.
2. net_sol_in lamports are transferred from buyer to the Vault PDA.
3. The curve math uses net_sol_in to calculate token_out.

Why "lock"?

The lock fee is non-extractable by design:

• The Curve PDA holds the locked SOL as part of its lamport balance.
• There is no instruction that transfers SOL out of the Curve PDA.
• The locked SOL increases the total economic backing of the token without increasing redeemable vault SOL.

This creates a deflationary flywheel:

More buys → More lock fees → More SOL permanently in curve PDA
         → Higher effective cumulative SOL → Higher token price
         → Existing holders benefit from increased backing

Comparison with trading fees

Sell side

Sell does not charge any fee.

When a seller burns tokens, they receive the full SOL amount calculated by the inverse curve. The protocol has already captured its 0.1% during the original buy. Charging a sell fee would:

1. Discourage exit liquidity
2. Create a "spread" that benefits no one (since fees are non-extractable)
3. Violate the principle of symmetric curve access

Economic impact model

For a token that accumulates 1000 SOL in buys:

Gross buys:     1,000 SOL
Lock fees:      1.0 SOL  (0.1%)
Net in vault:   999 SOL
Locked in curve: 1.0 SOL

Effective price impact: ~0.1% higher than "fee-free" curve
Token holder benefit: 1 SOL of permanent, non-extractable backing

At scale (e.g., 100,000 SOL cumulative buys):

Locked SOL: 100 SOL (~$15,000 at $150/SOL)
This is permanently removed from circulating economic supply.

Future considerations

Dynamic lock fee

The current 0.1% is fixed. A future protocol version could make LOCK_FEE_BASIS_POINTS configurable per-token or governed by protocol DAO. However, any increase would require careful consideration of:

• Early buyer incentive alignment
• Competitive positioning vs other launchpads
• Frontrunning resistance (higher fees = less profitable MEV)

Treasury usage

The treasury currently accumulates launch fees without on-chain disbursement. A future governance module could:

• Allocate treasury to protocol development
• Distribute to token holders (dividend model)
• Burn treasury SOL (additional deflation)

These decisions are intentionally left off-chain for the current protocol version to maintain minimal governance surface area.