# Nexis Gas Audit

> Nexis Gas Audit is a paid API for AI agents from api.nexismvp.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Audits real gas spend across up to 20 Base mainnet transaction hashes, returning total/average gas used, cost in ETH, and a per-transaction breakdown.

## Facts

- Endpoint: POST https://api.nexismvp.com/market/gas-audit
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/nexis-gas-audit-73e1f943
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_gSfAH0VyYWDj8zSmR89Er

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 nexis-gas-audit-73e1f943 -d '<json body>'
```

Example prompt: Can you audit the gas costs for these 5 Base mainnet transactions and tell me the total ETH spent, average gas used, and a breakdown per tx? Here are the hashes: 0xabc123..., 0xdef456..., 0x789ghi..., 0xjkl012..., 0xmno345...

## When to prefer this

Use this endpoint when you need to retrospectively audit actual on-chain gas costs for a known set of Base mainnet transactions — particularly useful for expense reporting, bot efficiency analysis, or post-deployment cost reviews. Prefer this over gas price estimators when you need real confirmed spend rather than predictions. Best suited for batches of 2–20 transactions where per-tx breakdown is needed alongside aggregates.

## Known failure modes

- Invalid or malformed transaction hashes return an error
- Transactions not found on Base mainnet (e.g. wrong network) return not-found errors
- Exceeding the 20-transaction limit per request returns a validation error
- RPC connectivity issues may cause timeouts or partial results
- Non-Base-mainnet tx hashes (e.g. Ethereum mainnet) will fail or return incorrect data

## How this service works

Audit real gas spend across up to 20 Base mainnet transaction hashes you provide — total/average gas used, cost in ETH, per-tx breakdown. POST body required. Experimental/informational only — not financial advice.

## Output

Returns a structured breakdown including total gas used across all submitted transactions, average gas used per transaction, total cost in ETH, and a per-transaction array showing each tx hash alongside its individual gas used and ETH cost.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "chain": {
   "enum": [
    "base"
   ],
   "type": "string",
   "description": "Only 'base' supported currently"
  },
  "tx_hashes": {
   "type": "array",
   "items": {
    "type": "string"
   },
   "maxItems": 20,
   "description": "Up to 20 transaction hashes to audit"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/nexis-gas-audit-73e1f943/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.nexismvp.com](https://www.zero.xyz/host/api.nexismvp.com/llms.txt)