require!(exact_in_amount > &0, ContractError::MinSwap);
pub fn validate(&self, params: &SwapParams) -> Result<()> {
    // ... existing validations ...
    
    if params.base_in {
        require!(
            params.exact_in_amount <= self.user_token_account.amount,
            ContractError::InsufficientBalance
        );
    } else {
        require!(
            params.exact_in_amount <= self.bonding_curve.real_sol_reserves,
            ContractError::InsufficientLiquidity
        );
    }
    
    Ok(())
}
