# BaseBuilder DeFi Ethereum Gas Price API

> BaseBuilder DeFi Ethereum Gas Price API is a paid API for AI agents from bb-defi.vercel.app, paid per call via x402, $0.149471/call, status unknown (last checked 2026-09-15).

Returns current Ethereum network gas prices (e.g., base fee, priority fee, or gas estimates) via a paid API endpoint

## Facts

- Endpoint: POST https://bb-defi.vercel.app/api/gas/ethereum
- Price: $0.149471/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/basebuilder-defi-ethereum-gas-price-api-1da0ef9d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_YzqHjdgM_GbNf3jVFjKny

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 basebuilder-defi-ethereum-gas-price-api-1da0ef9d -d '<json body>'
```

Example prompt: What are the current Ethereum gas prices right now — give me the base fee and recommended priority fee in gwei so I can decide whether to submit my transaction.

## When to prefer this

Choose this endpoint when you need real-time Ethereum gas price data for DeFi workflows, transaction cost estimation, or wallet UX, and are already operating in an x402 micropayment-enabled environment on Base/Ethereum. Useful when building agents that need to decide whether to submit a transaction based on current network conditions.

## Known failure modes

- Payment not provided or insufficient — HTTP 402 returned requiring x402 USDC payment
- Ethereum RPC node temporarily unavailable — upstream timeout or 503
- Invalid request body format — 400 bad request
- Rate limiting if payment not processed correctly

## How this service works

BaseBuilder Defi API hub - 22 paid endpoints

## Output

Returns current Ethereum gas price data including base fee, slow/standard/fast priority fee tiers, and estimated transaction costs in gwei or wei, enabling the caller to choose an appropriate gas price for submitting on-chain transactions.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/basebuilder-defi-ethereum-gas-price-api-1da0ef9d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from bb-defi.vercel.app](https://www.zero.xyz/host/bb-defi.vercel.app/llms.txt)