# EVM Gas Price API (Ethereum/Base/Polygon)

> EVM Gas Price API (Ethereum/Base/Polygon) is a paid API for AI agents from gateway.stride20k.com, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-11).

Returns current gas fees for Ethereum, Base, or Polygon — including node-reported gas price and EIP-1559 estimates (next base fee, p25/p50/p75 priority fees) derived from the last 5 blocks, in gwei.

## Facts

- Endpoint: GET https://gateway.stride20k.com/crypto/gas/:chain?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/evm-gas-price-api-ethereum-base-polygon-fb6c672b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_yR3JADwk7PUzXVYtJGRKi

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 evm-gas-price-api-ethereum-base-polygon-fb6c672b
```

Example prompt: What are the current EIP-1559 gas fees on Ethereum — give me the next base fee and the p25, p50, and p75 priority fees in gwei so I can decide whether to submit my transaction now.

## When to prefer this

Use this endpoint when you need real-time or near-real-time gas fee data for Ethereum, Base, or Polygon — especially when you need EIP-1559 priority fee percentiles (p25/p50/p75) from recent blocks for transaction cost estimation or fee optimization. Prefer this over generic block explorers when you need structured JSON output with percentile breakdowns and automatic fallback reliability. Not suitable for chains outside the three supported networks.

## Known failure modes

- Unsupported chain value (not ethereum/base/polygon) returns a 400 or validation error
- Upstream JSON-RPC node unreachable — fallback nodes attempted but may still fail with 502/503
- Stale cache (up to 15 seconds old) may not reflect very recent block activity
- Missing pathParam :chain results in 404 or routing error
- EIP-1559 fields absent on chains that don't support fee history

## How this service works

EVM gas price API: current gas fees for Ethereum, Base, Polygon, Arbitrum, Optimism, BSC, and Avalanche — node-reported gas price plus EIP-1559 estimates from the last 5 blocks: next base fee and 25th/50th/75th-percentile priority fees, in gwei. Read directly from public JSON-RPC nodes with automatic fallbacks. Use for transaction cost estimation, fee optimization, and timing on-chain actions. Cached up to 15 seconds.

## Output

A JSON object with the queried chain name, raw gas price in wei and gwei, projected next-block base fee in gwei, priority fee percentiles (p25/p50/p75) averaged over the last 5 blocks in gwei, number of blocks sampled, cache status, upstream source label, and the ISO 8601 timestamp when the data was fetched.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/evm-gas-price-api-ethereum-base-polygon-fb6c672b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from gateway.stride20k.com](https://www.zero.xyz/host/gateway.stride20k.com/llms.txt)