> ## Documentation Index
> Fetch the complete documentation index at: https://docs.chainstack.com/llms.txt
> Use this file to discover all available pages before exploring further.

# eth_feeHistory | Monad

> Monad API method that returns historical gas information, allowing you to track trends over time. Monad API method that returns historical gas information.

Monad API method that returns historical gas information, allowing you to track trends over time. This method is essential for building sophisticated gas estimation strategies based on recent network conditions.

<Note>
  **Monad-specific behavior**: Currently returns default values. This is temporary and will be updated with actual historical data in the future.
</Note>

## Parameters

* `blockCount` — the number of blocks in the requested range (1 to 1024).
* `newestBlock` — the highest block of the requested range as a hexadecimal string or block tag.
* `rewardPercentiles` — an array of floating point values between 0 and 100 to sample the effective priority fees.

## Response

* `result` — an object containing:
  * `oldestBlock` — the oldest block in the range
  * `baseFeePerGas` — array of base fees per gas for each block
  * `gasUsedRatio` — array of gas used ratios for each block
  * `reward` — array of arrays containing the requested percentile values of effective priority fees

## `eth_feeHistory` code examples

<CodeGroup>
  ```javascript ethers.js theme={"system"}
  const { ethers } = require("ethers");

  const provider = new ethers.JsonRpcProvider("CHAINSTACK_NODE_URL");

  async function getFeeHistory() {
    const feeHistory = await provider.send("eth_feeHistory", ["0x4", "latest", [25, 50, 75]]);
    console.log(`Oldest block: ${parseInt(feeHistory.oldestBlock, 16)}`);
    console.log("Base fees:", feeHistory.baseFeePerGas.map(fee => ethers.formatUnits(fee, "gwei") + " gwei"));
    console.log("Gas used ratios:", feeHistory.gasUsedRatio);
  }

  getFeeHistory();
  ```

  ```python web3.py theme={"system"}
  from web3 import Web3

  node_url = "CHAINSTACK_NODE_URL"

  web3 = Web3(Web3.HTTPProvider(node_url))
  fee_history = web3.eth.fee_history(4, 'latest', [25, 50, 75])

  print(f'Oldest block: {fee_history.oldestBlock}')
  print(f'Base fees: {[web3.from_wei(fee, "gwei") for fee in fee_history.baseFeePerGas]} gwei')
  print(f'Gas used ratios: {fee_history.gasUsedRatio}')
  ```
</CodeGroup>

## Use case

A practical use case for `eth_feeHistory` is building a gas price oracle that analyzes historical trends to predict optimal gas prices, or creating dashboards that visualize network congestion over time.


## OpenAPI

````yaml openapi/monad_node_api/gas_data/eth_feeHistory.json POST /
openapi: 3.0.0
info:
  title: Monad Node API
  version: 1.0.0
  description: This is an API for interacting with a Monad node.
servers:
  - url: https://monad-testnet.core.chainstack.com/9c5b265f20b3ea5df4f54f70eb74b800
security: []
paths:
  /:
    post:
      tags:
        - Gas data
      summary: eth_feeHistory
      operationId: eth_feeHistory
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              properties:
                id:
                  type: integer
                  default: 1
                jsonrpc:
                  type: string
                  default: '2.0'
                method:
                  type: string
                  default: eth_feeHistory
                params:
                  type: array
                  default:
                    - '0x4'
                    - latest
                    - - 25
                      - 75
      responses:
        '200':
          description: Fee history for the requested block range.
          content:
            application/json:
              schema:
                type: object
                properties:
                  jsonrpc:
                    type: string
                  id:
                    type: integer
                  result:
                    type: object

````