> For the complete documentation index, see [llms.txt](https://docs.rigoblock.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.rigoblock.com/solidity-api-reference/protocol/interfaces/ioracle.md).

# IOracle

## IOracle

### ObservationState

```solidity
struct ObservationState {
  uint16 index;
  uint16 cardinality;
  uint16 cardinalityNext;
}
```

### increaseCardinalityNext

```solidity
function increaseCardinalityNext(struct PoolKey key, uint16 cardinalityNext) external returns (uint16 cardinalityNextOld, uint16 cardinalityNextNew)
```

### getObservation

```solidity
function getObservation(struct PoolKey key, uint256 index) external view returns (struct Observation observation)
```

### getState

```solidity
function getState(struct PoolKey key) external view returns (struct IOracle.ObservationState state)
```

### observe

```solidity
function observe(struct PoolKey key, uint32[] secondsAgos) external view returns (int48[] tickCumulatives, uint144[] secondsPerLiquidityCumulativeX128s)
```