# x402 Base Tools – Gas & Transaction Cost Oracle

> x402 Base Tools – Gas & Transaction Cost Oracle is a paid API for AI agents from wt7tysfcmjm8fpzl.68r.lambda-web.us-east-1.on.aws, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-29).

Returns current Base L2 gas fees (base fee, priority fee percentiles), L1 data fee, and USD/ETH costs for common transaction types (ETH transfer, ERC-20 transfer, USDC x402 payment, swap, NFT mint) using Chainlink ETH/USD pricing.

## Facts

- Endpoint: GET https://wt7tysfcmjm8fpzl.68r.lambda-web.us-east-1.on.aws/v1/gas?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-base-tools-gas-transaction-cost-oracle-b9df98b1
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ErDX1h2ev7CBpbuyxStAm

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-base-tools-gas-transaction-cost-oracle-b9df98b1
```

Example prompt: What are current gas fees on Base right now — give me the base fee, priority fee ranges, and how much a USDC x402 payment and an ETH transfer would cost me in dollars?

## When to prefer this

Use this endpoint when you need real-time, multi-dimensional gas cost data on Base L2 specifically, especially for x402 payment flows (USDC transferWithAuthorization) or when you need transaction cost estimates in USD across several common transaction types in one call. Prefer this over generic Ethereum gas APIs when working on Base and when you need Chainlink-sourced ETH/USD pricing bundled with gas data.

## Known failure modes

- RPC node unreachable — may return 5xx or stale data
- Chainlink oracle temporarily unavailable — ETH/USD price may be absent
- Lambda cold start may add latency on first call
- Network congestion may cause slight staleness in fee data

## How this service works

Base mainnet data for agents, read live from the chain and paid per call in USDC: gas prices and costs, token prices from Uniswap and Aerodrome pools, balances, token info, transaction decoding, x402 payment checks, EIP-3009 authorization status, Basenames and address profiles. Lookups of things that do not exist are not charged.

## Output

A JSON object containing: the current block number, ETH/USD price (from Chainlink), base fee in gwei, priority fee percentiles (low/medium/high) in gwei over the last 10 blocks, L1 data fee, and estimated costs in both ETH and USD for common transaction types: ETH transfer, ERC-20 transfer, USDC transferWithAuthorization (x402 payment), swap, and NFT mint.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "block": "37000000",
  "costs": {
   "eth_transfer": {
    "eth": 7e-7,
    "gas": 21000,
    "usd": 0.0017
   }
  },
  "eth_usd": 2356.9,
  "base_fee_gwei": 0.005,
  "priority_fee_gwei": {
   "low": 0.0006,
   "high": 0.01,
   "medium": 0.002
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-base-tools-gas-transaction-cost-oracle-b9df98b1/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from wt7tysfcmjm8fpzl.68r.lambda-web.us-east-1.on.aws](https://www.zero.xyz/host/wt7tysfcmjm8fpzl.68r.lambda-web.us-east-1.on.aws/llms.txt)