# Base Gas Price Alert & Transaction Cost Monitor

> Base Gas Price Alert & Transaction Cost Monitor is a paid API for AI agents from defi-shield-hazel.vercel.app, paid per call via x402, $0.1/call, status unknown (last checked 2026-09-14).

Checks current Base network gas prices against a user-defined threshold and returns transaction cost estimates with actionable recommendations

## Facts

- Endpoint: POST https://defi-shield-hazel.vercel.app/api/monitor/gas-alert
- Price: $0.1/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/defi-shield-hazel-vercel-app-cacae77b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_XJQl7L7BivAyHprrhEAXE

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 defi-shield-hazel-vercel-app-cacae77b -d '<json body>'
```

Example prompt: Check if Base gas prices are currently below 0.5 gwei and give me an estimate of what a standard ERC-20 transfer would cost right now, plus a recommendation on whether I should wait or proceed.

## When to prefer this

Use this endpoint when an agent needs to make a real-time decision about submitting a transaction on Base and wants to compare current gas prices against a budget threshold, rather than just fetching raw gas data without context or recommendations.

## Known failure modes

- Base RPC node unavailable — returns error with no gas data
- Invalid threshold value provided — returns validation error
- Gas oracle data stale or unavailable — returns degraded estimate with warning
- Network congestion causing timeout — may return partial data

## Output

Returns the current Base gas price, whether it is above or below the specified threshold, estimated transaction costs in ETH and USD for the requested transaction type, and a recommendation on whether to proceed or wait for lower fees.

## Example request

```json
{
 "gasLimit": 21000,
 "threshold": 50,
 "notifyEmail": "zero-qa@agentmail.to"
}
```

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "bodyType",
    "body",
    "method"
   ],
   "properties": {
    "body": {
     "properties": {
      "threshold_gwei": {
       "type": "number",
       "description": "Gas price threshold in Gwei for alert (default: 50)"
      }
     }
    },
    "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"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/defi-shield-hazel-vercel-app-cacae77b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from defi-shield-hazel.vercel.app](https://www.zero.xyz/host/defi-shield-hazel.vercel.app/llms.txt)