> ## Documentation Index
> Fetch the complete documentation index at: https://daehan-base.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# eth_feeHistory

> Get historical gas fee information for a range of blocks

Defined in [EIP-1559](https://eips.ethereum.org/EIPS/eip-1559)

<Info>
  Returns a collection of historical gas information from which you can recompute gas costs and estimate future gas prices.
</Info>

## Parameters

<ParamField body="blockCount" type="string" required>
  Number of blocks in the requested range, as a hexadecimal string.
</ParamField>

<ParamField body="newestBlock" type="string" required>
  Highest block number in the requested range (hexadecimal) or "latest".
</ParamField>

<ParamField body="rewardPercentiles" type="array" required>
  Array of percentile values to sample from each block's effective priority fees.
</ParamField>

## Returns

<ResponseField name="result" type="object">
  Fee history data object containing gas information.

  <Expandable title="Fee history object properties">
    <ResponseField name="oldestBlock" type="string">
      Lowest block number in the range (hexadecimal).
    </ResponseField>

    <ResponseField name="baseFeePerGas" type="array">
      Array of block base fees per gas (hexadecimal strings).
    </ResponseField>

    <ResponseField name="gasUsedRatio" type="array">
      Array of block gas utilization ratios (numbers between 0 and 1).
    </ResponseField>

    <ResponseField name="reward" type="array">
      Array of effective priority fee per gas data points for each block (optional).
    </ResponseField>
  </Expandable>
</ResponseField>

<RequestExample>
  ```json Request theme={null}
  {
    "id": 1,
    "jsonrpc": "2.0",
    "method": "eth_feeHistory",
    "params": ["0x5", "latest", [20, 70]]
  }
  ```
</RequestExample>

<ResponseExample>
  ```json Success Response theme={null}
  {
    "id": 1,
    "jsonrpc": "2.0",
    "result": {
      "oldestBlock": "0x1",
      "baseFeePerGas": [
        "0x3b9aca00",
        "0x3ba1f3e2",
        "0x3a6db1e6"
      ],
      "gasUsedRatio": [
        0.5265,
        0.4858,
        0.6124
      ],
      "reward": [
        [
          "0x3b9aca00",
          "0x3b9aca00"
        ],
        [
          "0x3ba1f3e2",
          "0x3b9aca00"
        ],
        [
          "0x3a6db1e6",
          "0x3b9aca00"
        ]
      ]
    }
  }
  ```
</ResponseExample>

## Error Handling

| Code   | Message                        | Description                                       |
| ------ | ------------------------------ | ------------------------------------------------- |
| -32602 | Invalid params                 | Invalid block count, block number, or percentiles |
| 4100   | Requested method not supported | The method is not supported by the wallet         |

<Info>
  This method is useful for implementing dynamic fee estimation algorithms and understanding network congestion patterns.
</Info>