> For the complete documentation index, see [llms.txt](https://bonsaiswap.gitbook.io/bonsaiswap-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://bonsaiswap.gitbook.io/bonsaiswap-docs/developers/technical-reference/periphery/libraries/weightedoraclelibrary.md).

# WeightedOracleLibrary

Provides functions to integrate with different tier oracles of the same V3 pair

### Functions[​](https://docs.uniswap.org/contracts/v3/reference/periphery/libraries/WeightedOracleLibrary#functions) <a href="#functions" id="functions"></a>

#### consult[​](https://docs.uniswap.org/contracts/v3/reference/periphery/libraries/WeightedOracleLibrary#consult) <a href="#consult" id="consult"></a>

```solidity
  function consult(
    address pool,
    uint32 period
  ) internal view returns (struct WeightedOracleLibrary.PeriodObservation observation)
```

Fetches a time-weighted observation for a given Uniswap V3 pool

**Parameters:**[**​**](https://docs.uniswap.org/contracts/v3/reference/periphery/libraries/WeightedOracleLibrary#parameters)

| Name     | Type    | Description                                                                      |
| -------- | ------- | -------------------------------------------------------------------------------- |
| `pool`   | address | Address of the pool that we want to observe                                      |
| `period` | uint32  | Number of seconds in the past to start calculating the time-weighted observation |

**Return Values:**[**​**](https://docs.uniswap.org/contracts/v3/reference/periphery/libraries/WeightedOracleLibrary#return-values)

| Name          | Type    | Description                                                                                   |
| ------------- | ------- | --------------------------------------------------------------------------------------------- |
| `observation` | address | An observation that has been time-weighted from (block.timestamp - period) to block.timestamp |

#### getArithmeticMeanTickWeightedByLiquidity[​](https://docs.uniswap.org/contracts/v3/reference/periphery/libraries/WeightedOracleLibrary#getarithmeticmeantickweightedbyliquidity) <a href="#getarithmeticmeantickweightedbyliquidity" id="getarithmeticmeantickweightedbyliquidity"></a>

```solidity
  function getArithmeticMeanTickWeightedByLiquidity(
    struct WeightedOracleLibrary.PeriodObservation[] observations
  ) internal pure returns (int24 arithmeticMeanWeightedTick)
```

Given some time-weighted observations, calculates the arithmetic mean tick, weighted by liquidity

In most scenarios, each entry of `observations` should share the same `period` and underlying `pool` tokens. If `period` differs across observations, the result becomes difficult to interpret and is likely biased/manipulable. If the underlying `pool` tokens differ across observations, extreme care must be taken to ensure that both prices and liquidity values are comparable. Even if prices are commensurate (e.g. two different USD-stable assets against ETH), liquidity values may not be, as decimals can differ between tokens.

**Parameters:**[**​**](https://docs.uniswap.org/contracts/v3/reference/periphery/libraries/WeightedOracleLibrary#parameters-1)

| Name           | Type                                              | Description                          |
| -------------- | ------------------------------------------------- | ------------------------------------ |
| `observations` | struct WeightedOracleLibrary.PeriodObservation\[] | A list of time-weighted observations |

**Return Values:**[**​**](https://docs.uniswap.org/contracts/v3/reference/periphery/libraries/WeightedOracleLibrary#return-values-1)

| Name                         | Type                                              | Description                                                                                      |
| ---------------------------- | ------------------------------------------------- | ------------------------------------------------------------------------------------------------ |
| `arithmeticMeanWeightedTick` | struct WeightedOracleLibrary.PeriodObservation\[] | The arithmetic mean tick, weighted by the observations' time-weighted harmonic average liquidity |