# EVM Gas Cost Estimator – Multi-Chain USD Fee Comparison

> EVM Gas Cost Estimator – Multi-Chain USD Fee Comparison is a paid API for AI agents from api.x402node.dev, paid per call via x402, $0.012/call, status unknown (last checked 2026-09-16).

Estimates the USD gas cost of a standard EVM transaction (transfer, ERC-20 transfer, approve, swap, NFT mint) across multiple EVM chains by combining live gas prices with native token prices.

## Facts

- Endpoint: GET https://api.x402node.dev/chain/gas-estimate
- Price: $0.012/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/evm-gas-cost-estimator-multi-chain-usd-fee-comparison-7c64fc8e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_8y9h3C889GPd9v4aSplRe

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-cost-estimator-multi-chain-usd-fee-comparison-7c64fc8e
```

Example prompt: What's the cheapest EVM chain right now to do a token swap — give me the USD gas cost estimate for a swap action across the main chains so I can pick the best one.

## When to prefer this

Use this endpoint when an AI agent needs to make a cost-aware decision about which EVM chain to execute a transaction on, or when budgeting a DeFi or NFT interaction in USD terms. Prefer this over static fee tables when you need live, real-time USD cost estimates that reflect current gas market conditions and token prices across multiple chains in a single call.

## Known failure modes

- Unsupported action type returns a 400 or error body indicating invalid action enum value
- Unknown or unsupported chain ID returns an error response
- Live gas price or token price feed unavailable causes stale or failed estimate
- Payment not attached (x402) results in 402 Payment Required with no data
- Network timeout fetching live gas/price data causes delayed or empty response

## How this service works

Estimates the USD gas cost of a common action (transfer, erc20-transfer, approve, swap, nft-mint) across EVM chains, combining live gas price per chain with the native token price. Lets an agent pick the cheapest chain to execute and budget a transaction. Live aggregated gas + price compute. gas cost estimate, transaction fee usd, cheapest chain to execute, swap gas Accepts payment on Base or Solana — either network works.

## Output

Returns the estimated USD cost of the requested transaction type on one or more EVM chains, calculated from live on-chain gas prices combined with the current native token price. Includes the raw gas price, token price, computed USD fee, and likely identifies the cheapest chain to execute on.

## 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"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "gas": {
       "type": "string",
       "description": "optional custom gas units"
      },
      "chain": {
       "type": "string",
       "description": "optional single chain; omit for all"
      },
      "action": {
       "type": "string",
       "description": "transfer/erc20-transfer/approve/swap/nft-mint (default swap)"
      }
     }
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/evm-gas-cost-estimator-multi-chain-usd-fee-comparison-7c64fc8e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.x402node.dev](https://www.zero.xyz/host/api.x402node.dev/llms.txt)