# Sentinel Preflight Trust Check

> Sentinel Preflight Trust Check is a paid API for AI agents from sentinel-awms.onrender.com, paid per call via x402, $0.025/call, status unknown (last checked 2026-09-15).

Runs a pre-transaction trust check on a Base blockchain address, returning a composite trust score, letter grade, risk verdict, and per-dimension checks (token, protocol, position, counterparty) backed by on-chain EAS attestations.

## Facts

- Endpoint: POST https://sentinel-awms.onrender.com/preflight
- Price: $0.025/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/sentinel-preflight-trust-check-72223221
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_CSdD9R6ojNj4miilbfQvV

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 sentinel-preflight-trust-check-72223221 -d '<json body>'
```

Example prompt: Before my agent swaps on Uniswap V3, run a Sentinel preflight trust check on 0x2626664c2603336e57b271c5c0b26f421741e481 on Base and tell me the trust grade, composite score, and whether it's safe to proceed.

## When to prefer this

Use this endpoint when an AI agent needs to gate an on-chain action on Base behind a trust check — especially before token swaps, DeFi deposits, or any autonomous transaction involving an unknown protocol, token, or counterparty. Prefer it over generic block explorer lookups when you need a structured, scored, attestation-backed verdict rather than raw chain data.

## Known failure modes

- Unknown or unattested address returns null checks and lower composite score
- Invalid Ethereum address format returns 400 error
- Rate limit exceeded (>25 free calls/day) without USDC payment returns 402 Payment Required
- Base RPC or EAS indexer downtime causes 503 or timeout
- Contract not deployed on Base returns protocol check as null

## How this service works

Trust infrastructure for autonomous AI agents on Base. Verify protocols, tokens, positions, and counterparties with on-chain EAS attestations. 25 free calls/day, then pay per query in USDC via x402.

## Output

Returns a JSON object with: the target address, chain ('base'), a boolean 'proceed' recommendation, a string 'verdict' (e.g. LOW_RISK), a letter 'trust_grade' (A–F), a numeric 'composite_score' (0–100), and a 'checks' object with per-dimension grades or null for token, position, protocol, and counterparty.

## Example request

```json
{
 "chain": "base",
 "detail": "standard",
 "address": "0x940181a94A35A4569E4529A3CDfB74e38FD98631"
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "chain": "base",
  "checks": {
   "token": null,
   "position": "C",
   "protocol": "B",
   "counterparty": null
  },
  "target": "0x2626664c2603336e57b271c5c0b26f421741e481",
  "proceed": true,
  "verdict": "LOW_RISK",
  "trust_grade": "B",
  "composite_score": 74
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/sentinel-preflight-trust-check-72223221/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from sentinel-awms.onrender.com](https://www.zero.xyz/host/sentinel-awms.onrender.com/llms.txt)