> ## Documentation Index
> Fetch the complete documentation index at: https://docs.krokoswap.io/llms.txt
> Use this file to discover all available pages before exploring further.

# V2 Fees

> Fee structure for V2 constant product pools

# V2 Fees

All V2 pools charge a **fixed 0.3% fee** on every swap. This fee is not configurable per pool.

## How Fees Work

The fee is applied to the input token before the swap calculation:

1. Trader sends `amountIn` of token A
2. The effective input is `amountIn × 0.997` (0.3% deducted)
3. The output amount is calculated using the reduced input
4. The fee portion remains in the pool, increasing `k`

```
Input: 1000 tokens
Fee:   1000 × 0.003 = 3 tokens
Effective input: 997 tokens → used for swap calculation
```

## Fee Accumulation

Fees are not distributed separately — they accumulate directly in the pool reserves. This means:

* `k` grows over time as fees are collected
* LP token value increases proportionally
* LPs claim their fees when they withdraw liquidity (burn LP tokens)

## Example

A pool with 100,000 A / 100,000 B reserves:

| Day | Swap Volume | Fees Collected | New k           |
| --- | ----------- | -------------- | --------------- |
| 1   | 10,000 A    | 30 A           | Slightly higher |
| 2   | 50,000 B    | 150 B          | Higher still    |

Over time, the pool reserves grow from accumulated fees, benefiting all LP token holders proportionally to their share.

## Comparison with V3

|                | V2                                | V3                                    |
| -------------- | --------------------------------- | ------------------------------------- |
| Fee rate       | Fixed 0.3%                        | Selectable (0.01%, 0.05%, 0.3%, 1%)   |
| Fee collection | Auto-compounded into reserves     | Collected separately, must be claimed |
| Fee per LP     | Distributed evenly across all LPs | Only earned by in-range positions     |