# SignGate Agent Buyer Address Risk Check

> SignGate Agent Buyer Address Risk Check is a paid API for AI agents from base-agent-preflight.bytoken2023.workers.dev, paid per call via x402, $0.01/call, status down (last checked 2026-09-15).

Screens a blockchain wallet address for risk level before an AI agent proceeds with an x402 micropayment purchase

## Facts

- Endpoint: GET https://base-agent-preflight.bytoken2023.workers.dev/v1/x402/agent-risk/address-risk
- Price: $0.01/call
- Payment: x402
- Status: down
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/signgate-agent-buyer-address-risk-check-8cf7a915
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_kzs7NLS7EL5oZlgVaaNn_

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 signgate-agent-buyer-address-risk-check-8cf7a915
```

Example prompt: Before my agent pays for that x402 API, can you run a risk check on the buyer wallet address 0xAbC1234567890abcdef1234567890abcdef123456 on the Base network to make sure it's not flagged?

## When to prefer this

Use this endpoint when an AI agent is about to execute an x402 micropayment and you need a fast, pre-transaction risk gate specifically designed for agent buyer governance. Prefer this over generic blockchain analytics when you need a simple pass/fail risk score with flags tailored to the x402 purchase context (APIs, datasets, tools). It is particularly useful for autonomous agent pipelines that need lightweight, cheap ($0.01 USDC) compliance checks without heavy KYC infrastructure.

## Known failure modes

- Invalid address format (not a 0x hex address of 40 chars) returns a validation error
- Unsupported or unrecognized chain label may return empty or error response
- Missing required query params (chain or address) returns 400-level error
- Address not found on-chain may return low score with no data rather than an error
- Service unavailability from Cloudflare Workers results in 5xx with no assessment

## How this service works

Pay-per-request identity, risk, authorization, execution-preflight and evidence APIs for autonomous agents.

## Output

Returns a JSON object with the network identifier (e.g. 'eip155:8453'), product name ('address-risk'), and an assessment object containing: risk_level (e.g. 'low', 'medium', 'high'), numeric risk_score (0–100), and a flags array listing any specific risk signals detected. May also include identity, activity, and provenance sub-objects for additional context.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "chain",
      "address"
     ],
     "properties": {
      "chain": {
       "type": "string",
       "pattern": "^[A-Za-z0-9:_ -]{2,80}$",
       "description": "Chain or network label for the address."
      },
      "action": {
       "type": "string",
       "pattern": "^[A-Za-z0-9_.:-]{2,80}$",
       "description": "Planned agent action, such as payment, approval, onboarding, or call."
      },
      "address": {
       "type": "string",
       "pattern": "^0x[a-fA-F0-9]{40}$",
       "description": "Wallet or contract address to screen."
      }
     }
    }
   },
   "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": "address-risk",
  "assessment": {
   "flags": [],
   "risk_level": "low",
   "risk_score": 0
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/signgate-agent-buyer-address-risk-check-8cf7a915/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)