Ethereum gas price API: base fee, tip and transfer cost

$0.01 per call · failed calls are never charged · no account or subscription: pay per call with a card key or USDC

Current gas price on Ethereum (eth_gasPrice): gas price, base fee and suggested priority fee in gwei, plus what a plain ETH transfer (21,000 gas) costs right now. Takes no input. Use before sending a transaction or to decide whether to wait; for the fee a past transaction actually paid use eth_receipt.

When to use it

Guide: Gas price API

Run it free (25 free calls) Buy credits by card (from $1) Example result (JSON)

Request

Over HTTP, with a card key from /credits:

curl -H "Authorization: Bearer adt_…" "https://tools.funwords.eu/eth/gas?format=json"

Or one of your 25 free calls, no key:

curl "https://tools.funwords.eu/eth/gas?format=json&trial=1"

Without a key, the same URL answers 402 Payment Required with x402 and MPP terms, so an agent with a wallet pays per call in USDC (Base, Polygon, Arbitrum or Solana over x402; Base or Tempo over MPP) and retries.

Example result

{
  "chain": "Ethereum",
  "chainId": 1,
  "gasPriceGwei": "0.015",
  "baseFeeGwei": "0.012",
  "priorityFeeGwei": "0.001",
  "transferCost": "0.000000315",
  "symbol": "ETH",
  "block": 123456789
}

From an AI agent (MCP)

Add the MCP server to Claude, Cursor or any MCP client. This tool is eth_gas, and the first 25 successful calls are free:

https://tools.funwords.eu/mcp

Questions

Does it need any input?

No. It takes no input and reads the latest Ethereum gas data.

How do I pay?

Each successful call costs $0.01; failed calls are not charged. The first 25 calls are free. Then pay with card credits (from $1; the key goes in an Authorization header or, for clients that can only fetch a URL, as api_key= in the URL) or per call in USDC over x402 or MPP. No account is needed.

Related tools