# x402 Gas Price Oracle

> x402 Gas Price Oracle is a paid API for AI agents from x402tap.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-10).

Returns current gas price and EIP-1559 fee estimates (base fee, priority fee) for major EVM chains including Base, Ethereum, Polygon, Arbitrum, and Optimism

## Facts

- Endpoint: GET https://x402tap.com/api/gas-price?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-10
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-gas-price-oracle-5ef196d5
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_4V71o80Zaq-WMGtBkOf4I

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 x402-gas-price-oracle-5ef196d5
```

Example prompt: What are the current gas fees on Ethereum right now — give me the base fee and priority fee in Gwei so I know what to set for my transaction?

## When to prefer this

Use this endpoint when you need real-time EIP-1559-compatible gas fee data (base fee + priority fee) for one of the five supported chains (Base, Ethereum, Polygon, Arbitrum, Optimism) and want a simple, single-call lookup without running your own RPC node. Ideal for agents that need to estimate transaction costs or decide which chain to use based on current fees. Not suitable for historical gas price analysis or chains outside the supported set.

## Known failure modes

- Unsupported chain name returns an error or empty response
- Stale data if underlying RPC is delayed or unavailable
- Network timeout if the chain RPC node is congested
- Missing or misspelled chain query param defaults to Base silently

## How this service works

Current gas price and EIP-1559 fee estimate for a chain (base, ethereum, polygon, arbitrum, optimism)

## Output

A JSON object containing the chain name, current gas price in Gwei, native token symbol (e.g. ETH), maxFeePerGasGwei (EIP-1559 max fee), and maxPriorityFeePerGasGwei (tip/priority fee) — all values are real-time estimates suitable for transaction fee configuration.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "chain": {
       "type": "string",
       "description": "Chain to query: base, ethereum, polygon, arbitrum, optimism (default base)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "chain": "Base",
  "gasPriceGwei": 0.012,
  "nativeSymbol": "ETH",
  "maxFeePerGasGwei": 0.015,
  "maxPriorityFeePerGasGwei": 0.001
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-gas-price-oracle-5ef196d5/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402tap.com](https://www.zero.xyz/host/x402tap.com/llms.txt)