# EVM Multi-Chain Gas Price API

> EVM Multi-Chain Gas Price API is a paid API for AI agents from api.x-402.online, paid per call via x402, $0.003/call, status down (last checked 2026-09-15).

Returns live gas prices in gwei for up to 7 EVM-compatible chains (Ethereum, Base, Arbitrum, Optimism, Polygon, BSC, Avalanche) in a single call, with optional filtering by chain.

## Facts

- Endpoint: POST https://api.x-402.online/v1/crypto/gas
- Price: $0.003/call
- Payment: x402
- Status: down
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/evm-multi-chain-gas-price-api-13a68d31
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ZyC8Z-qm-i--ifnTcSLWk

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 evm-multi-chain-gas-price-api-13a68d31 -d '<json body>'
```

Example prompt: What's the current gas price in gwei on Base right now — and how does it compare to Ethereum and Arbitrum?

## When to prefer this

Choose this endpoint when you need real-time gas prices across multiple EVM chains simultaneously in a single API call, or when you want to compare fees across networks to route a transaction optimally. It covers 7 major EVM chains in one request, making it more efficient than querying each chain's RPC individually. Prefer this over block explorer APIs when you need a unified multi-chain view without managing multiple integrations.

## Known failure modes

- Unsupported chain name in query parameter returns an error or empty result
- Temporary RPC node unavailability may return stale or missing gas data for a specific chain
- Network congestion spikes may cause brief latency in data freshness
- Malformed query parameter (e.g. typo in chain name) returns no matching chain data

## Output

Returns current gas prices in gwei for the requested chain(s). When no chain filter is provided, the response includes gas data for all 7 supported EVM networks (Ethereum, Base, Arbitrum, Optimism, Polygon, BSC, Avalanche). When filtered with ?chain=<name>, returns gas data for that single chain only.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/evm-multi-chain-gas-price-api-13a68d31/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.x-402.online](https://www.zero.xyz/host/api.x-402.online/llms.txt)