# EVM Gas Fees

> EVM Gas Fees is a paid API for AI agents from bess-x402.onrender.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-30).

Returns current EIP-1559 gas fees (base fee, priority tiers, max fee in gwei, block utilisation) for Ethereum, Base, Arbitrum, Optimism, or Polygon.

## Facts

- Endpoint: GET https://bess-x402.onrender.com/v1/chain/gas?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/evm-gas-fees-5d9a8204
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_H6ny5UPsZqzirWYrfgWH4

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-fees-5d9a8204
```

Example prompt: What are the current EIP-1559 gas fees on Ethereum — give me the slow, standard, and fast priority fees and next base fee in gwei so I know what to set before sending my transaction.

## When to prefer this

Use this endpoint immediately before submitting an EVM transaction when you need accurate, live EIP-1559 gas parameters rather than stale estimates. Ideal for comparing gas costs across the five supported chains (Ethereum, Base, Arbitrum, Optimism, Polygon) in a single call per chain. Not suitable if you need L2 L1-data fee breakdowns or historical gas data.

## Known failure modes

- Invalid or unsupported chain name returns a validation error
- RPC or upstream node unavailability may return a 503 or timeout
- Chain enum must exactly match one of: ethereum, base, arbitrum, optimism, polygon — typos cause 400 errors
- Payment failure (insufficient USDC) results in 402 Payment Required

## How this service works

Current EIP-1559 gas fees for Ethereum, Base, Arbitrum, Optimism or Polygon: next base fee, slow/standard/fast priority and max fee in gwei, block utilisation and the cost of a plain transfer (L2 L1-data fees excluded). Use right before sending a transaction or to compare chains.

## Output

Returns the current EIP-1559 gas parameters for the requested chain: next base fee, slow/standard/fast priority fees, and max fee all in gwei, current block utilisation percentage, and the estimated cost of a plain native-token transfer (note: L2 L1-data fees are excluded).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "chain"
     ],
     "properties": {
      "chain": {
       "enum": [
        "arbitrum",
        "base",
        "ethereum",
        "optimism",
        "polygon"
       ],
       "type": "string",
       "description": "EVM chain"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/evm-gas-fees-5d9a8204/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from bess-x402.onrender.com](https://www.zero.xyz/host/bess-x402.onrender.com/llms.txt)