# BaseBuilder DeFi Gas Price API – Polygon

> BaseBuilder DeFi Gas Price API – Polygon is a paid API for AI agents from bb-defi.vercel.app, paid per call via x402, $0.196001/call, status unknown (last checked 2026-09-16).

Returns current gas price data for the Polygon network to help users estimate and optimize transaction costs.

## Facts

- Endpoint: POST https://bb-defi.vercel.app/api/gas/polygon
- Price: $0.196001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/basebuilder-defi-gas-price-api-polygon-7cba59cc
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_rr1t8ErnrytgPW0kT0haH

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-gas-price-api-polygon-7cba59cc -d '<json body>'
```

Example prompt: What's the current gas price on Polygon right now — I want to know if it's a good time to send a transaction?

## When to prefer this

Use this endpoint when you need real-time Polygon gas prices specifically and are operating in a Web3/DeFi agent context that supports x402 micropayment protocol. Prefer this over free public RPC calls when you need reliable, aggregated gas data without managing your own node infrastructure.

## Known failure modes

- Polygon RPC node unavailable — upstream data source error
- Rate limit exceeded — too many requests in a short period
- Payment validation failure — USDC payment not accepted or insufficient
- Network congestion causing stale or delayed gas data
- 500 internal server error if the backend aggregator is down

## How this service works

BaseBuilder Defi API hub - 22 paid endpoints

## Output

Returns current gas price information for the Polygon network, likely including standard, fast, and slow gas price tiers in Gwei, helping the caller estimate transaction costs before submitting on-chain.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/basebuilder-defi-gas-price-api-polygon-7cba59cc/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)