Get fee history API

Retrieve the fee history for Base Mainnet blocks, including base fees and reward percentiles. Supports EIP-1559.

The Get fee history operation is part of the Base Chain Data API on BRAINIAC.software. Retrieve the fee history for Base Mainnet blocks, including base fees and reward percentiles. Supports EIP-1559. It is exposed as POST /api/v1/chain-data/gas/fee-history and priced at $0.03 USDC on Base. Payment uses the x402 exact scheme: an unpaid call returns HTTP 402 with payment requirements; after paying the exact USDC amount, retry the same request with a payment-signature header and Idempotency-Key. No account and no API key are required. Data sources for this product: Base Mainnet public JSON-RPC Limitations: Reads do not submit transactions. Log and transfer queries are capped and require a bounded block range. Outputs are compliance prechecks, drafts, or data lookups for human review. They are not official determinations, legal advice, identity confirmation, or certified filings. Related operations in this group include Get network information, Get latest block, Get block by number or hash, Get block transactions. Open the group documentation for the full request schema, field notes, and response examples before integrating.

POST$0.03 USDC
/api/v1/chain-data/gas/fee-history

Example request

curl -i -X POST "https://www.brainiac.software/api/v1/chain-data/gas/fee-history" \
  -H 'content-type: application/json' \
  -H 'Idempotency-Key: <fresh-64-character-random-hex-key>' \
  --data-binary @- <<'JSON'
{
  "blockCount": 100,
  "rewardPercentiles": [
    25,
    50,
    75
  ]
}
JSON

An unpaid probe returns HTTP 402 with x402 payment requirements. After paying the exact USDC amount on Base, retry the identical request with a payment-signature header.

FAQ

  • Do I need an API key? No. Pay the listed USDC amount with x402.
  • What network? Base (eip155:8453), USDC.
  • Is this an official determination? No. Results are for human review against the cited sources.

Related APIs

Base Chain Data APIFull docsHow it works