> ## 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.

# V3 Factory 与 Pool

> V3 流动性池创建和 Pool 合约接口

# V3 Factory 与 Pool

## V3 Factory

V3 Factory 负责创建和索引 V3 流动性池。与 V2 不同，相同的代币对可以拥有**多个不同费率等级的流动性池**。

### 核心函数

#### getPool

返回指定代币对和费率等级的流动性池地址。

```solidity theme={null}
function getPool(
    address tokenA,
    address tokenB,
    uint24 fee
) external view returns (address pool);
```

| 参数                 | 描述                                |
| ------------------ | --------------------------------- |
| `tokenA`, `tokenB` | 代币地址（顺序无关）                        |
| `fee`              | 费率等级：`100`、`500`、`3000` 或 `10000` |

如果流动性池不存在则返回零地址。

### ABI

```json theme={null}
[
  "function getPool(address tokenA, address tokenB, uint24 fee) view returns (address pool)"
]
```

***

## V3 Pool

每个 V3 Pool 合约管理特定代币对和费率等级的集中流动性仓位和兑换执行。

### 核心函数

#### slot0

返回当前流动性池状态。

```solidity theme={null}
function slot0() external view returns (
    uint160 sqrtPriceX96,
    int24 tick,
    uint16 observationIndex,
    uint16 observationCardinality,
    uint16 observationCardinalityNext,
    uint8 feeProtocol,
    bool unlocked
);
```

| 返回值            | 描述                           |
| -------------- | ---------------------------- |
| `sqrtPriceX96` | 当前价格，表示为 sqrt(price) \* 2^96 |
| `tick`         | 当前 tick 索引                   |
| `feeProtocol`  | 协议费率设置                       |
| `unlocked`     | 重入保护状态                       |

#### liquidity

返回当前活跃的（在范围内的）总流动性。

```solidity theme={null}
function liquidity() external view returns (uint128);
```

#### fee / tickSpacing

```solidity theme={null}
function fee() external view returns (uint24);
function tickSpacing() external view returns (int24);
```

#### token0 / token1

```solidity theme={null}
function token0() external view returns (address);
function token1() external view returns (address);
```

### ABI

```json theme={null}
[
  "function slot0() view returns (uint160 sqrtPriceX96, int24 tick, uint16 observationIndex, uint16 observationCardinality, uint16 observationCardinalityNext, uint8 feeProtocol, bool unlocked)",
  "function liquidity() view returns (uint128)",
  "function fee() view returns (uint24)",
  "function tickSpacing() view returns (int24)",
  "function token0() view returns (address)",
  "function token1() view returns (address)"
]
```

### 示例：读取池价格

```typescript theme={null}
const FACTORY_ABI = [
  "function getPool(address, address, uint24) view returns (address)"
];
const POOL_ABI = [
  "function slot0() view returns (uint160, int24, uint16, uint16, uint16, uint8, bool)",
  "function token0() view returns (address)",
  "function token1() view returns (address)",
  "function fee() view returns (uint24)",
  "function liquidity() view returns (uint128)"
];

const factory = new ethers.Contract(V3_FACTORY, FACTORY_ABI, provider);
const poolAddress = await factory.getPool(tokenA, tokenB, 3000); // 0.3% 费率

if (poolAddress === ethers.ZeroAddress) {
  console.log("Pool does not exist for this fee tier");
} else {
  const pool = new ethers.Contract(poolAddress, POOL_ABI, provider);
  const [sqrtPriceX96, tick] = await pool.slot0();

  // 将 sqrtPriceX96 转换为价格
  const price = (Number(sqrtPriceX96) / 2 ** 96) ** 2;
  console.log(`Current price (token1/token0): ${price}`);
  console.log(`Current tick: ${tick}`);
}
```

### 价格转换

流动性池以 `sqrtPriceX96` 格式存储价格。转换方法如下：

```typescript theme={null}
// sqrtPriceX96 → 价格（token1 每 token0）
const price = (sqrtPriceX96 / 2n ** 96n) ** 2n; // BigInt 写法

// 针对不同代币精度的调整
const adjustedPrice = price * 10n ** BigInt(decimals0 - decimals1);
```

如需精确计算，请使用 `@uniswap/v3-sdk` 库或参阅 [Ticks 和范围](/concepts/v3/ticks-and-ranges) 中的公式。