# Vextorium Gas Price Multi-Chain Comparator

> Vextorium Gas Price Multi-Chain Comparator is a paid API for AI agents from api.vextorium.com, paid per call via x402, $0.004/call, status unknown (last checked 2026-10-28).

Returns current gas prices and estimated USD transaction costs (native transfer, ERC-20 transfer, swap) across Base, Ethereum, Arbitrum, Optimism, and Polygon, plus identifies the cheapest chain for swaps.

## Facts

- Endpoint: POST https://api.vextorium.com/v1/gas-compare-chains?utm_source=zero.xyz
- Price: $0.004/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-28
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/vextorium-gas-price-multi-chain-comparator-8907b214
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_fHLIgMXYHaD90kQUPuhAK

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 vextorium-gas-price-multi-chain-comparator-8907b214 -d '<json body>'
```

Example prompt: What are the current gas prices on Base, Ethereum, Arbitrum, Optimism, and Polygon right now, and which chain is cheapest to do a swap on — show me the USD cost for a native transfer, ERC-20 transfer, and swap on each?

## When to prefer this

Use this endpoint when you need a real-time, multi-chain gas fee comparison across the five major EVM networks (Base, Ethereum, Arbitrum, Optimism, Polygon) in a single call. It is ideal when you need to route a transaction to the cheapest chain, estimate USD costs for common transaction types (native transfer, ERC-20 transfer, swap), or surface gas data to end users before they sign a transaction. Prefer this over individual chain RPC calls when you need normalized, USD-denominated cost estimates across all chains simultaneously.

## Known failure modes

- External RPC or gas oracle unavailable — may return null values for affected networks
- Native token price feed unavailable — price fields may be null (e.g. pol: null)
- Network congestion or timeout causing stale or missing gas data for one or more chains
- Invalid or missing request body causing 400-level error

## How this service works

558 pay-per-call data APIs for AI agents: Solana and EVM on-chain data, tokenized stocks, DeFi, Hyperliquid, economy and official statistics, FX, validation, web and developer tools. Pay in USDC via x402.

## Output

Returns a JSON object with an array of per-network gas data (gas in gwei, native token symbol, USD cost of native transfer, ERC-20 transfer, and swap), the name of the cheapest chain for swapping, and current native asset prices in USD (ETH, POL). Also includes a note about L2 chains having an additional L1 data fee not captured in the estimates.

## 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",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "required": [],
     "properties": {}
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": [
      "object",
      "null"
     ],
     "properties": {
      "note": {
       "type": [
        "string",
        "null"
       ]
      },
      "networks": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": [
         "null",
         "object"
        ],
        "properties": {
         "native": {
          "type": [
           "null",
           "string"
          ]
         },
         "network": {
          "type": [
           "null",
           "string"
          ]
         },
         "gas_gwei": {
          "type": [
           "null",
           "number"
          ]
         },
         "swap_usd": {
          "type": [
           "null",
           "number"
          ]
         },
         "transfer_usd": {
          "type": [
           "null",
           "number"
          ]
         },
         "token_transfer_usd": {
          "type": [
           "null",
           "number"
          ]
         }
        }
       }
      },
      "cheapest_swap": {
       "type": [
        "string",
        "null"
       ]
      },
      "native_prices_usd": {
       "type": [
        "object",
        "null"
       ],
       "properties": {
        "eth": {
         "type": [
          "number",
          "null"
         ]
        },
        "pol": {}
       }
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "note": "On L2s (Base, Arbitrum, Optimism) a small L1 data fee is added that is not included here.",
  "networks": [
   {
    "native": "ETH",
    "network": "base",
    "gas_gwei": 0.006008,
    "swap_usd": 0.00293,
    "transfer_usd": 0.00034,
    "token_transfer_usd": 0.00106
   },
   {
    "native": "ETH",
    "network": "ethereum",
    "gas_gwei": 0.902926,
    "swap_usd": 0.44,
    "transfer_usd": 0.05133,
    "token_transfer_usd": 0.15889
   }
  ],
  "cheapest_swap": "optimism",
  "native_prices_usd": {
   "eth": 2707.22696629,
   "pol": null
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/vextorium-gas-price-multi-chain-comparator-8907b214/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.vextorium.com](https://www.zero.xyz/host/api.vextorium.com/llms.txt)