# Base Gas Price & Transfer Cost Estimator

> Base Gas Price & Transfer Cost Estimator is a paid API for AI agents from api.x-402.online, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-22).

Returns the current Base network gas price, base fee, priority fee, and ETH cost of ETH, ERC-20, and x402 USDC transfers at that gas price.

## Facts

- Endpoint: GET https://api.x-402.online/v1/chain/gas?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-22
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/base-gas-price-transfer-cost-estimator-a3c2af63
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_GKqD0AqwiPjG1kLsHN6t-

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 base-gas-price-transfer-cost-estimator-a3c2af63
```

Example prompt: What are the current gas fees on Base right now — including the base fee, priority fee, and how much it would cost in ETH to do an ETH transfer, an ERC-20 transfer, and an x402 USDC settlement?

## When to prefer this

Use this endpoint when you need real-time Base L2 gas fee data specifically, especially when estimating the ETH cost of x402 USDC settlements or comparing ETH vs ERC-20 transfer costs on Base. Prefer this over generic Ethereum mainnet gas APIs when operating on Base chain or building x402-compatible payment flows.

## Known failure modes

- Base RPC node unavailable — service may return 503 or stale data
- Network congestion causing momentary data inconsistency
- Occasional latency spikes if gas oracle is slow to respond
- Invalid or unexpected response shape if Base undergoes a hard fork changing gas mechanics

## How this service works

Get the current Base gas price and the ETH cost of an ETH, ERC-20 or x402 USDC transfer at that price. Current Base gas: gas price, base fee, priority fee, and the ETH cost of an ETH transfer, an ERC-20 transfer and an x402 USDC settlement at that price. Query: none.

## Output

A JSON object containing the current Base network gas price, base fee, priority fee in Gwei or Wei, and the computed ETH cost (in ETH and/or USD) for three transaction types: a plain ETH transfer, an ERC-20 token transfer, and an x402 USDC settlement.

## 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": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/base-gas-price-transfer-cost-estimator-a3c2af63/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)