# Open position

Before you want to deposit liquidity, you need to choose an appropriate price range (corresponding to the tick range) to open a position. 

There are two situations:

* open a position only
* open positon and add liquidity **(recommended)**

In most cases, opening a position and adding liquidity are supposed to be done simultaneously.

## 1. Open a position only

Use `sdk.Position.openPositionTransactionPayload()` method.

#### Function input params

*Please refer to the original function for specific parameter types.*

* **`poolID`**: The object id about which pool you want to operation.
* **`coinTypeA`**: the coin type address about coinA.
* **`coinTypeB`**: the coin type address about coinB.
* **`tickLower`**: Represents the index of the lower tick boundary.
* **`tickUpper`**: Represents the index of the upper tick boundary.

{% hint style="info" %}

* The tick index must be an integer multiple of `tickSpacing`. If the provided parameter is not a multiple of `tickSpacing`, the contract will throw an error.
* -443636 < `tickLowerIndex` < `tickUpperIndex` < 443636, 443636 is a constant, derived from the maximum range representable by the Q32.62 fixed-point number format.
* If you know price range, then you can use `TickMath.priceToTickIndex()` to transform real price to tick index.
* You can just open one position near the current price of the pool, use `TickMath.getPrevInitializableTickIndex()` and `TickMath.getNextInitializableTickIndex()` to find the next initialized tick.
* If you want to add global liquidity, you can set `tickLowerIndex` = - 443636 + (443636 % tick\_spacing), `tickUpperIndex` = 443636 - (443636 % tick\_spacing)
  {% endhint %}

#### Example:

```ts
const sendKeypair = buildTestAccount()
// fetch pool data
const pool = await sdk.Pool.getPool(poolAddress)
// build tick range
const lowerTick = TickMath.getPrevInitializableTickIndex(
      new BN(pool.current_tick_index).toNumber(),
      new BN(pool.tickSpacing).toNumber()
    )
const upperTick = TickMath.getNextInitializableTickIndex(
      new BN(pool.current_tick_index).toNumber(),
      new BN(pool.tickSpacing).toNumber()
    )
// build open position payload
const openPositionTransactionPayload = sdk.Position.openPositionTransactionPayload({
      coinTypeA: pool.coinTypeA,
      coinTypeB: pool.coinTypeB,
      tick_lower: lowerTick.toString(),
      tick_upper: upperTick.toString(),
      pool_id: pool.poolAddress,
    })
console.log('openPositionTransactionPayload: ', openPositionTransactionPayload)

const transferTxn = await sdk.fullClient.sendTransaction(sendKeypair,openPositionTransactionPayload)
```

## 2. Open position with add liquidity

Use `sdk.Position.createAddLiquidityFixTokenPayload()` method.

#### Function input params

*Please refer to the original function for specific parameter types.*

* **`poolID`**: The object id about which pool you want to operation.
* **`coinTypeA`**: the coin type address about coinA.
* **`coinTypeB`**: the coin type address about coinB.
* **`tickLower`**: Represents the index of the lower tick boundary.
* **`tickUpper`**: Represents the index of the upper tick boundary.

{% hint style="info" %}

* The tick index must be an integer multiple of `tickSpacing`. If the provided parameter is not a multiple of `tickSpacing`, the contract will throw an error.
* -443636 < `tickLowerIndex` < `tickUpperIndex` < 443636, 443636 is a constant, derived from the maximum range representable by the Q32.62 fixed-point number format.
* If you know price range, then you can use `TickMath.priceToTickIndex()` to transform real price to tick index.
* You can just open one position near the current price of the pool, use `TickMath.getPrevInitializableTickIndex()` and `TickMath.getNextInitializableTickIndex()` to find the next initialized tick.
* If you want to add global liquidity, you can set `tickLowerIndex` = - 443636 + (443636 % tick\_spacing), `tickUpperIndex` = 443636 - (443636 % tick\_spacing)
  {% endhint %}

- **`isOpen`**: `true` means if first add liquidity, so needs open one position.
- **`posID`**: The object id about position.
- **`fixAmountA`**: `true` means fixed coinA amount, `false` means fixed coinB amount
- **`amountA`**: If fixed amount A, you must set `amountA`, `amountB` will be auto calculated by `ClmmPoolUtil.estLiquidityAndcoinAmountFromOneAmounts()`.
- **`amountB`**: If fixed amount B, you must set `amountB`, `amountA` will be auto calculated by `ClmmPoolUtil.estLiquidityAndcoinAmountFromOneAmounts()`.

{% hint style="info" %}
`ClmmPoolUtil.estLiquidityAndcoinAmountFromOneAmounts()` calculate result means when fixed one coin amount, another coin amount will change because of pool price change. so it will calculated based on the current pool price and processed with slippage.
{% endhint %}

* **`slippage`**: Price slippage point.
* **`collectFee`**: If you already has one position, you can select collect fees while adding liquidity.
* **`rewarderCoinTypes`**: If these not empty, it will collect rewarder in this position, if you already open the position.

#### Example

```ts
const poolObjectId = '0xcf994611fd4c48e277ce3ffd4d4364c914af2c3cbb05f7bf6facd371de688630' //  TokensMapping.USDT_USDC_LP.poolObjectIds[0]
const pool = await buildTestPool(sdk, poolObjectId)
const lowerTick = TickMath.getPrevInitializableTickIndex(
  new BN(pool.current_tick_index).toNumber(),
  new BN(pool.tickSpacing).toNumber()
)
const upperTick = TickMath.getNextInitializableTickIndex(
  new BN(pool.current_tick_index).toNumber(),
  new BN(pool.tickSpacing).toNumber()
)
const coinAmount = new BN(100)
const fix_amount_a = true
const slippage = 0.01
const curSqrtPrice = new BN(pool.current_sqrt_price)

const liquidityInput = ClmmPoolUtil.estLiquidityAndcoinAmountFromOneAmounts(
  lowerTick,
  upperTick,
  coinAmount,
  fix_amount_a,
  true,
  slippage,
  curSqrtPrice
)

const amount_a = fix_amount_a ? coinAmount.toNumber() : liquidityInput.tokenMaxA.toNumber()
const amount_b = fix_amount_a ? liquidityInput.tokenMaxB.toNumber() : coinAmount.toNumber()

console.log('amount: ', { amount_a, amount_b })

const addLiquidityPayloadParams: AddLiquidityFixTokenParams = {
  coinTypeA: pool.coinTypeA,
  coinTypeB: pool.coinTypeB,
  pool_id: pool.poolAddress,
  tick_lower: lowerTick.toString(),
  tick_upper: upperTick.toString(),
  fix_amount_a,
  amount_a,
  amount_b,
  slippage,
  is_open: true,
  rewarder_coin_types: [],
  collect_fee: false,
  pos_id: '',
}
const createAddLiquidityTransactionPayload = await sdk.Position.createAddLiquidityFixTokenPayload(addLiquidityPayloadParams, {
  slippage: slippage,
  curSqrtPrice: curSqrtPrice,
})

printTransaction(createAddLiquidityTransactionPayload)
const transferTxn = await sdk.fullClient.sendTransaction(sendKeypair, createAddLiquidityTransactionPayload)
console.log('open_and_add_liquidity_fix_token: ', transferTxn)
```