FeeHistory has no information about blob gas

[StackOverflowExcept1on]

pub base_fee_per_blob_gas: Vec<u128>,
pub blob_gas_used_ratio: Vec<f64>,

viem/src/types/fee.ts

Lines 3 to 15 in 0cb1b2e

	export type FeeHistory<quantity = bigint> = {
	/**
	* An array of block base fees per gas (in wei). This includes the next block after
	* the newest of the returned range, because this value can be derived from the newest block.
	* Zeroes are returned for pre-EIP-1559 blocks. */
	baseFeePerGas: quantity[]
	/** An array of block gas used ratios. These are calculated as the ratio of gasUsed and gasLimit. */
	gasUsedRatio: number[]
	/** Lowest number block of the returned range. */
	oldestBlock: quantity
	/** An array of effective priority fees (in wei) per gas data points from a single block. All zeroes are returned if the block is empty. */
	reward?: quantity[][] | undefined
	}

https://docs.rs/alloy/latest/alloy/rpc/types/struct.FeeHistory.html

{
  "method": "eth_feeHistory",
  "params": [
    "0x2",
    "latest",
    []
  ],
  "id": 0,
  "jsonrpc": "2.0"
}

{
  "jsonrpc": "2.0",
  "id": 0,
  "result": {
    "baseFeePerGas": [
      "0x18f0c80",
      "0x15d5c78",
      "0x131dc48"
    ],
    "gasUsedRatio": [
      0.0019393333333333333,
      0.0019397333333333333
    ],
    "baseFeePerBlobGas": [
      "0x1",
      "0x1",
      "0x1"
    ],
    "blobGasUsedRatio": [
      0,
      0
    ],
    "oldestBlock": "0x1e",
    "reward": []
  }
}

[sueun-dev]

yeah this is a real gap — confirmed by looking at the source. the FeeHistory type in src/types/fee.ts only has baseFeePerGas, gasUsedRatio, oldestBlock, and reward. no blob gas fields at all, even though eth_feeHistory returns baseFeePerBlobGas and blobGasUsedRatio post-Dencun (EIP-4844).

interestingly, viem already has getBlobBaseFee as a separate action, so it's not like blob gas is unknown territory in the codebase. the FeeHistory type just never got updated after the Dencun upgrade landed.

files that would need changes:

• src/types/fee.ts — add baseFeePerBlobGas: quantity[] and blobGasUsedRatio: number[] to the FeeHistory type
• src/utils/formatters/feeHistory.ts — update formatFeeHistory to handle the new fields
• RPC type definitions — make sure the raw RPC response type includes the blob fields

for reference, alloy on the Rust side already has both fields in their FeeHistory struct: https://docs.rs/alloy/latest/alloy/rpc/types/struct.FeeHistory.html

quick sketch of the type change:

export type FeeHistory<quantity = bigint> = {
  baseFeePerGas: quantity[]
  gasUsedRatio: number[]
  oldestBlock: quantity
  reward?: quantity[][] | undefined
  // EIP-4844 blob gas fields
  baseFeePerBlobGas?: quantity[]
  blobGasUsedRatio?: number[]
}

made them optional since pre-Dencun nodes won't return them. would be worth opening a PR for this — pretty straightforward change.