# NythosX Gas Price Comparator

> NythosX Gas Price Comparator is a paid API for AI agents from tools.nythosx.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-22).

Returns current transaction cost estimates in USD across up to six blockchains, ranked from cheapest to most expensive, for a given transaction type and speed tier.

## Facts

- Endpoint: GET https://tools.nythosx.com/v1/gas/compare?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-22
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/nythosx-gas-price-comparator-3b0f8936
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_fhX99ZsIMpfDpJAhGvqgu

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 nythosx-gas-price-comparator-3b0f8936
```

Example prompt: What's the cheapest chain to do a standard USDC transfer on right now — can you compare gas costs across all supported networks and tell me which one wins?

## When to prefer this

Use this endpoint when an agent or user needs to choose the most cost-efficient blockchain for executing a transaction and wants a single ranked comparison across multiple networks in real time. Prefer it over manually querying each chain's RPC or using static fee tables, especially for USDC transfers or swaps where L1 data fees on rollups are a significant factor.

## Known failure modes

- One or more chains fail to return fee data and appear in the 'failed' array rather than ranking
- Invalid enum value for 'tx' or 'tier' query parameters returns a validation error
- Payment failure or x402 authentication issue prevents the call from completing
- Network timeouts on individual chain RPC nodes cause partial results

## How this service works

Pay-per-call tools for autonomous agents: current gas and fee prices across six chains, and web page to clean Markdown. x402 v2, USDC, Base (Solana optional).

## Output

A JSON object containing the transaction type and tier queried, an ordered ranking array of chains with their current USD cost and block number, whether L1 data fees are included, the name of the cheapest chain, and a list of any chains that failed to return data.

## 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",
     "required": [],
     "properties": {
      "tx": {
       "enum": [
        "transfer",
        "usdc_transfer",
        "swap"
       ],
       "type": "string",
       "default": "transfer",
       "description": "Transaction type"
      },
      "tier": {
       "enum": [
        "slow",
        "standard",
        "fast"
       ],
       "type": "string",
       "default": "standard",
       "description": "Speed tier"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "tx": "usdc_transfer",
  "tier": "standard",
  "failed": [
   {
    "name": "Polygon PoS",
    "chain": "polygon"
   }
  ],
  "ranking": [
   {
    "name": "Solana",
    "block": 245123456,
    "chain": "solana",
    "costUsd": 0.0011,
    "l1DataFeeIncluded": false
   },
   {
    "name": "Base",
    "block": 21512345,
    "chain": "base",
    "costUsd": 0.0012,
    "l1DataFeeIncluded": true
   }
  ],
  "cheapest": "solana"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/nythosx-gas-price-comparator-3b0f8936/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from tools.nythosx.com](https://www.zero.xyz/host/tools.nythosx.com/llms.txt)