# Gas Oracle & EIP-1559 Fee Estimator for Base Chain

> Gas Oracle & EIP-1559 Fee Estimator for Base Chain is a paid API for AI agents from x402-deployer.x402-deployer.workers.dev, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-14).

Reads the latest Base chain block, derives EIP-1559 base fee, suggests priority fees for safe-low/standard/fast tiers, and converts gas costs to USD for common transaction types.

## Facts

- Endpoint: POST https://x402-deployer.x402-deployer.workers.dev/gas-now-base
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-deployer-x402-deployer-workers-dev-6c052299
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_jwt_WlIALVaUwfzsRjUJY

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 x402-deployer-x402-deployer-workers-dev-6c052299 -d '<json body>'
```

Example prompt: What are the current gas fees on Base right now — give me the safe-low, standard, and fast tiers in gwei and also tell me how much a Uniswap swap would cost in USD at the standard tier?

## When to prefer this

Use this endpoint when you need real-time EIP-1559 gas fee estimates specifically for the Base chain, including USD cost breakdowns for common transaction types, without needing a full Etherscan API key or running your own node. Ideal for pre-transaction cost checks in DeFi agents operating on Base.

## Known failure modes

- RPC node unavailable or rate-limited — upstream fetch failure
- Stale block data if Base RPC is lagging
- USD price feed unavailable — ETH/USD conversion may fail
- Malformed POST body — validation error
- Network timeout from Cloudflare Worker to Base RPC

## How this service works

Gas oracle / gas price API / EIP-1559 fee estimator / Base + Ethereum + Optimism + Arbitrum + Polygon gas tracker / etherscan-gas alternative / pre-tx cost estimator / USD gas-cost calculator / safe-low + standard + fast tier feed. Reads the chain's latest block, derives the EIP-1559 base fee, suggests priority fees for safe-low / standard / fast tiers, computes the total recommended maxFeePerGas, and converts cost to USD for common tx types (transfer, ERC-20 transfer, Uniswap swap, NFT mint).

## Output

Returns the current EIP-1559 base fee from the latest Base block, recommended priority fees and maxFeePerGas values for safe-low, standard, and fast tiers, and USD cost estimates for common transaction types including ETH transfer, ERC-20 transfer, Uniswap swap, and NFT mint.

## 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": {
     "properties": {
      "chain": {
       "enum": [
        "base",
        "ethereum",
        "optimism",
        "arbitrum",
        "polygon"
       ],
       "type": "string",
       "description": "EVM L1/L2 to read gas from. Default 'base'."
      }
     }
    },
    "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",
     "properties": {
      "chain": {
       "type": "string"
      },
      "cost_usd": {
       "type": "object",
       "properties": {
        "nft_mint": {
         "type": "number"
        },
        "transfer": {
         "type": "number"
        },
        "uniswap_swap": {
         "type": "number"
        },
        "erc20_transfer": {
         "type": "number"
        }
       }
      },
      "timestamp": {
       "type": "string"
      },
      "block_number": {
       "type": "integer"
      },
      "base_fee_gwei": {
       "type": "number"
      },
      "eth_price_usd": {
       "type": "integer"
      },
      "priority_fee_gwei": {
       "type": "object",
       "properties": {
        "fast": {
         "type": "number"
        },
        "safe_low": {
         "type": "number"
        },
        "standard": {
         "type": "number"
        }
       }
      },
      "total_recommended_gwei": {
       "type": "number"
      }
     }
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-deployer-x402-deployer-workers-dev-6c052299/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-deployer.x402-deployer.workers.dev](https://www.zero.xyz/host/x402-deployer.x402-deployer.workers.dev/llms.txt)