# Crystal Crypto Risk Evidence via SumSub — x402 Preflight Check

> Crystal Crypto Risk Evidence via SumSub — x402 Preflight Check is a paid API for AI agents from base-agent-preflight.bytoken2023.workers.dev, paid per call via x402, $0.05/call, status unknown (last checked 2026-09-15).

Checks a wallet address against SumSub/Crystal crypto risk data to assess AML risk level before an AI agent makes an x402 purchase.

## Facts

- Endpoint: GET https://base-agent-preflight.bytoken2023.workers.dev/v1/x402/sumsub/crystal-crypto-risk-evidence
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/crystal-crypto-risk-evidence-via-sumsub-x402-preflight-check-96d15802
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_fMQ3NTWGEjavuY3XH9iXf

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 crystal-crypto-risk-evidence-via-sumsub-x402-preflight-check-96d15802
```

Example prompt: Before my agent pays for that x402 API, run a Crystal crypto risk check on the seller wallet 0xAbCd1234abcd1234abcd1234abcd1234abcd1234 and tell me if it's low risk.

## When to prefer this

Use this endpoint when an AI agent or automated workflow needs to screen a crypto wallet for AML/compliance risk specifically using Crystal's blockchain analytics before executing an x402 micropayment. Prefer this over generic wallet lookup tools when you need a structured risk score with flags from a KYC/AML-grade provider (SumSub Crystal), particularly for Base network (eip155:8453) transactions.

## Known failure modes

- Invalid wallet address format (must be 0x + 40 hex chars) returns validation error
- Unknown or unindexed wallet returns empty activity data with default low score
- Network unavailable or SumSub API timeout returns 503
- Invalid transaction_reference format returns 400 bad request
- Payment of $0.05 USDC not settled results in 402 response blocking the check

## How this service works

Machine-payable service intelligence for discovering, verifying, and monitoring identity, risk, authorization, execution-preflight, and evidence APIs before autonomous agents spend.

## Output

Returns a JSON object with the network (e.g. eip155:8453/Base), product name, risk level (low/medium/high), numeric risk score, and an array of risk flags from Crystal's AML database. An empty flags array and risk_score of 0 indicates a clean wallet.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "wallet"
     ],
     "properties": {
      "wallet": {
       "type": "string",
       "pattern": "^0x[a-fA-F0-9]{40}$",
       "description": "Wallet or crypto counterparty address."
      },
      "transaction_reference": {
       "type": "string",
       "pattern": "^[A-Za-z0-9._:-]{1,128}$",
       "description": "Crypto transaction or SignGate request reference."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "network": {
       "type": "string"
      },
      "product": {
       "type": "string"
      },
      "activity": {
       "type": "object"
      },
      "identity": {
       "type": "object"
      },
      "assessment": {
       "type": "object"
      },
      "provenance": {
       "type": "object"
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "network": "eip155:8453",
  "product": "sumsub-crystal-crypto-risk-evidence",
  "assessment": {
   "flags": [],
   "risk_level": "low",
   "risk_score": 0
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/crystal-crypto-risk-evidence-via-sumsub-x402-preflight-check-96d15802/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from base-agent-preflight.bytoken2023.workers.dev](https://www.zero.xyz/host/base-agent-preflight.bytoken2023.workers.dev/llms.txt)