# 402Sentinel Deep Assessment

> 402Sentinel Deep Assessment is a paid API for AI agents from 402sentinel.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-14).

Scores an x402 payment counterparty 0-100 for risk using on-chain settlement behaviour and returns an allow/review/block decision before you pay

## Facts

- Endpoint: POST https://402sentinel.com/api/assess/deep
- 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/402sentinel-deep-assessment-af95e1c1
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_A4eGDl0BhL-44Z42XO1Lz

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 402sentinel-deep-assessment-af95e1c1 -d '<json body>'
```

Example prompt: Before paying that x402 API, run a deep risk check on counterparty address 0xAbC...123 on Base and tell me the risk score and whether I should allow, review, or block the payment.

## When to prefer this

Choose this endpoint when an AI agent needs to gate an x402 payment decision with on-chain counterparty risk data before committing funds, especially when the counterparty address is unfamiliar, newly encountered, or flagged for review. Prefer the deep assessment variant over lighter checks when settlement maturity and facilitator-aware payer diversity signals are needed for a thorough risk evaluation.

## Known failure modes

- Address not found on Base — insufficient on-chain history to score
- Invalid or malformed address input — 400 error
- Address too new with no settlement history — low-confidence score returned
- x402 payment for the call itself fails — 402 response before assessment is returned
- Rate limiting or service unavailability — 503 error

## How this service works

Is this payment address safe to pay? DEEP version — deep counterparty assessment: same shape as /api/assess but scans more on-chain settlement history for higher confidence. POST {target:{payto_address}, payment_context?, policy?}. Returns risk_score 0-100, allow/review/block, confidence, per-dimension signals, key_factors and a recommended_policy. Use when the payment is large enough that a thin-data 'review' verdict is not good enough.

## Output

Returns a 0-100 risk score and a three-tier decision (allow / review / block) derived from on-chain signals including address age, facilitator-aware payer diversity, and settlement maturity for the assessed counterparty address.

## Example request

```json
{
 "policy": {
  "min_confidence": 0.5,
  "max_payment_usdc": 50,
  "review_ceiling_usdc": 5
 },
 "target": {
  "payto_address": "0x6a5e7d954f49712abf3f873f037ec845b7b8c666"
 },
 "payment_context": {
  "asset": "USDC",
  "amount": 10
 }
}
```

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "policy": {
   "type": "object",
   "description": "Optional caller policy hints."
  },
  "target": {
   "type": "object",
   "required": [
    "payto_address"
   ],
   "properties": {
    "payto_address": {
     "type": "string",
     "description": "Address that receives the payment — 0x EVM (Base) OR base58 Solana."
    }
   },
   "description": "The x402 seller to score."
  },
  "payment_context": {
   "type": "object",
   "properties": {
    "asset": {
     "type": "string",
     "description": "e.g. \"USDC\""
    },
    "amount": {
     "type": "number"
    }
   },
   "description": "Optional context about the payment being considered."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/402sentinel-deep-assessment-af95e1c1/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from 402sentinel.com](https://www.zero.xyz/host/402sentinel.com/llms.txt)