# Gas Oracle – EIP-1559 Fee Estimator by Chain

> Gas Oracle – EIP-1559 Fee Estimator by Chain is a paid API for AI agents from x402.professorsausages.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Returns current bid-ready EIP-1559 gas fees (slow/standard/fast) plus native-token USD costs for a specified blockchain

## Facts

- Endpoint: GET https://x402.professorsausages.com/gas-oracle/:chain
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/gas-oracle-eip-1559-fee-estimator-by-chain-1d2f26cf
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_1KGhGzsVJJhz41rmkuqcX

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability gas-oracle-eip-1559-fee-estimator-by-chain-1d2f26cf
```

Example prompt: What are the current EIP-1559 gas fees on Ethereum — give me the slow, standard, and fast tiers with maxFeePerGas and maxPriorityFeePerGas in wei, and tell me roughly what a standard transfer costs in USD?

## When to prefer this

Use this endpoint when you need production-ready EIP-1559 gas fee parameters (maxFeePerGas and maxPriorityFeePerGas in wei) for constructing or estimating blockchain transactions, especially when you also need USD cost context via native token price from Chainlink. Prefer this over manual RPC calls when you want pre-computed slow/standard/fast tiers, next-block base fee projections, and congestion signals in a single call.

## Known failure modes

- Unsupported chain name returns 404 or error response
- Chain RPC node unavailable causes fetch failure
- Stale cache served if upstream data is delayed
- Malformed chain parameter may return 400 bad request
- Rate limiting or payment failure returns 402 or 429

## How this service works

Current gas market for one chain — bid-ready EIP-1559 fees + USD costs

## Output

A JSON object containing the current block number, baseFee in wei and gwei, projected nextBaseFee, priority fee percentiles over the last 20 blocks, three ready-to-use EIP-1559 fee tiers (slow/standard/fast) each with maxFeePerGas and maxPriorityFeePerGas in wei, native token USD price with Chainlink metadata, quick USD cost estimates, congestion indicators, legacy gas price in gwei, cache hit/miss/stale status, and a fetchedAt timestamp.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/gas-oracle-eip-1559-fee-estimator-by-chain-1d2f26cf/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.professorsausages.com](https://www.zero.xyz/host/x402.professorsausages.com/llms.txt)