# Multi-chain Gas Oracle (x402)

> Multi-chain Gas Oracle (x402) is a paid API for AI agents from gas-oracle.frcompanycheck.workers.dev, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-20).

Returns EIP-1559 gas price data (base fee, priority fee percentiles, suggested maxFee/priority) for Ethereum, Base, Arbitrum, Optimism, Polygon, and BSC via public RPCs, paid per-call with USDC over x402.

## Facts

- Endpoint: GET https://gas-oracle.frcompanycheck.workers.dev/v1/%7Bchain%7D/gas?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/multi-chain-gas-oracle-x402-c1b285e9
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_PJa_GzFV6Mfg0Mf_xmGpm

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 multi-chain-gas-oracle-x402-c1b285e9
```

Example prompt: What are the current EIP-1559 gas prices on Base — give me the base fee, suggested maxFee, and priority fee so I can set my transaction parameters?

## When to prefer this

Choose this endpoint when you need a quick, no-API-key EIP-1559 gas estimate for any of the six supported EVM chains (Ethereum, Base, Arbitrum, Optimism, Polygon, BSC) and want structured fee data (base fee, maxFee, priority fee) in a single pay-per-call request. Prefer it over free public RPC calls when you want a normalized, parsed JSON response without handling raw eth_gasPrice or eth_feeHistory RPC responses yourself.

## Known failure modes

- Unsupported chain name returns an error — only ethereum, base, arbitrum, optimism, polygon, and bsc are valid
- Public RPC unavailability for the requested chain may cause timeouts or stale data
- Missing or malformed x402 USDC payment on Base results in a 402 Payment Required response
- Rate limits or public RPC throttling may degrade response freshness under high load

## How this service works

Pay-per-call EIP-1559 gas oracle for AI agents: ethereum, base, arbitrum, optimism, polygon, bsc. Returns gas_price, base_fee, priority fee percentiles and suggested maxFee/priority. Public RPCs only, no API key. x402 USDC on Base.

## Output

A JSON object containing the chain name, chain ID, current base fee in gwei, gas price in gwei, suggested maxFee per gas in gwei, and suggested priority fee in gwei, derived from live public RPC data for the requested EVM-compatible network.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "properties": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "chain": "base",
  "chain_id": 8453,
  "base_fee_gwei": 0.005,
  "gas_price_gwei": 0.006,
  "suggested_max_fee_gwei": 0.011,
  "suggested_priority_gwei": 0.001
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/multi-chain-gas-oracle-x402-c1b285e9/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from gas-oracle.frcompanycheck.workers.dev](https://www.zero.xyz/host/gas-oracle.frcompanycheck.workers.dev/llms.txt)