# x402 Base Tools – Gas & Transaction Cost Oracle

> x402 Base Tools – Gas & Transaction Cost Oracle is a paid API for AI agents from base.kagurazaka.dev, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-29).

Returns current Base network gas fees (base fee, priority fee percentiles, L1 data fee) and the USD/ETH cost of common transaction types including ETH transfers, ERC-20 transfers, USDC x402 payments, swaps, and NFT mints.

## Facts

- Endpoint: GET https://base.kagurazaka.dev/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-b83621f7
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_NX77LueM2cEHoaxeyrPm6

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-b83621f7
```

Example prompt: What's the current gas situation on Base right now — base fee, priority fee percentiles, and how much would a USDC x402 payment and a regular ETH transfer cost me in USD?

## When to prefer this

Use this endpoint when you need a single, unified snapshot of Base network gas conditions AND the real USD cost of specific transaction types (including x402/USDC payments) — especially when you need ETH/USD pricing from Chainlink baked in. Prefer this over raw RPC calls when you want pre-calculated USD costs for ETH transfers, ERC-20 transfers, swaps, and NFT mints without doing the math yourself.

## Known failure modes

- Chainlink price feed unavailable — ETH/USD price may be stale or missing
- Base RPC node timeout — may return 502/503 if upstream node is unresponsive
- x402 payment failure — endpoint costs $0.001 USDC per call; unpaid requests return 402
- Gas oracle calculation error if block data is temporarily unavailable

## How this service works

Current Base gas: base fee, priority fee percentiles over the last 10 blocks, the L1 data fee of a typical transaction, and what an ETH transfer, an ERC-20 transfer, a USDC transferWithAuthorization (an x402 payment), a swap and an NFT mint cost now in ETH and USD (ETH/USD from Chainlink).

## 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, and a cost breakdown for common transaction types (ETH transfer, ERC-20 transfer, USDC transferWithAuthorization, swap, NFT mint) each expressed in both ETH and USD.

## 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-b83621f7/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from base.kagurazaka.dev](https://www.zero.xyz/host/base.kagurazaka.dev/llms.txt)