# 402Sentinel x402 Counterparty Risk Gate

> 402Sentinel x402 Counterparty Risk Gate 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).

Assesses an x402 payment counterparty's on-chain risk before payment, returning a 0-100 risk score and an allow/review/block decision based on settlement behavior.

## Facts

- Endpoint: POST https://402sentinel.com/api/compliance
- 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-x402-counterparty-risk-gate-37c20d66
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_VP07bSLKZ4o7MFuA70vYB

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-x402-counterparty-risk-gate-37c20d66 -d '<json body>'
```

Example prompt: Before I pay this x402 API, run a risk check on the counterparty address 0x6a5e7d954f49712abf3f873f037ec845b7b8c666 on Base — I want at least 0.5 confidence and I'm planning to pay up to $10 USDC, so flag anything over $5 for review.

## When to prefer this

Use this endpoint when your AI agent is about to make an x402 pay-per-call payment and needs to assess counterparty risk before committing funds. It is specifically designed for the x402 protocol and on-chain settlement behavior on Base, making it superior to generic blockchain analytics tools that lack x402-specific signals like facilitator-aware payer diversity and settlement maturity.

## Known failure modes

- Unknown or brand-new address with no on-chain history returns low confidence score and likely a review/block decision
- Invalid or malformed payto_address causes a validation error
- Network not supported returns an error or empty result
- Payment for the compliance check itself fails (x402 payment required, $0.02 USDC on Base)
- Timeout if on-chain data indexing is delayed

## How this service works

Pre-pay COMPLIANCE screen for regulated onchain flows. POST {target:{payto_address, agent_id?}, payment_context?:{amount,asset}} returns compliance_decision pass/flag/block, diligence_tier, obligations and checks: OFAC sanctions (hard block), counterparty due-diligence tier, structuring detection (sub-threshold payments aggregating within 24h, needs agent_id), FATF Travel-Rule threshold as informational. Screening support, not legal advice.

## Output

Returns a 0-100 risk score, an allow/review/block decision, and supporting signals derived from on-chain settlement behavior including address age, payer diversity, and settlement maturity. Enables the calling agent to gate or proceed with an x402 payment automatically.

## 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": {
  "target": {
   "type": "object",
   "required": [
    "payto_address"
   ],
   "properties": {
    "agent_id": {
     "type": "string",
     "description": "Optional: the paying agent's id — enables structuring/smurfing detection from its payment history."
    },
    "payto_address": {
     "type": "string",
     "description": "0x EVM address that receives the payment."
    }
   },
   "description": "The payee to screen (+ optional payer agent_id for structuring detection)."
  },
  "payment_context": {
   "type": "object",
   "properties": {
    "asset": {
     "type": "string"
    },
    "amount": {
     "type": "number",
     "description": "Payment amount (USD-equivalent)."
    }
   },
   "description": "Payment amount drives the Travel-Rule threshold check."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/402sentinel-x402-counterparty-risk-gate-37c20d66/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)