# Xerxes Base Gas Price API

> Xerxes Base Gas Price API is a paid API for AI agents from ari001.tailb4ac3a.ts.net, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-15).

Returns the current base gas price, base fee, and priority fee on the Base blockchain at the chain head (not a per-call estimate).

## Facts

- Endpoint: GET https://ari001.tailb4ac3a.ts.net/v1/base/gas
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/xerxes-base-gas-price-api-3c7d2f16
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ag5kAHgHCxqlDN13b0iVi

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 xerxes-base-gas-price-api-3c7d2f16
```

Example prompt: What's the current base fee and priority fee on Base right now — I want to know the live gas prices at the chain head before I submit a transaction.

## When to prefer this

Use this endpoint when an agent needs real-time, raw EIP-1559 gas parameters (base fee + priority fee) on the Base L2 network at the current chain head, especially before constructing or submitting a transaction. Prefer this over Ethereum mainnet gas APIs when the target chain is Base specifically.

## Known failure modes

- RPC node unavailable or unresponsive — returns error indicating dead RPC
- Network congestion may cause slight staleness in returned values
- Payment not provided or invalid x402 payment header — returns 402 Payment Required
- Malformed request — returns 4xx error

## How this service works

Base gas price, base fee and priority fee at head. Not an estimate of a specific call. Unread RPC is not zero.

## Output

Returns the current base gas price, EIP-1559 base fee, and priority fee (miner tip) as observed at the latest block head on the Base network. These are network-level values, not estimates for a specific transaction or call.

## 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",
     "properties": {}
    }
   },
   "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/xerxes-base-gas-price-api-3c7d2f16/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from ari001.tailb4ac3a.ts.net](https://www.zero.xyz/host/ari001.tailb4ac3a.ts.net/llms.txt)