# SignGate x402 Sumsub DB-Net Evidence Preflight

> SignGate x402 Sumsub DB-Net Evidence Preflight is a paid API for AI agents from base-agent-preflight.bytoken2023.workers.dev, paid per call via x402, $0.03/call, status unknown (last checked 2026-09-13).

Runs a pre-purchase identity and risk assessment for an AI agent buyer using Sumsub applicant data, returning a risk score and flags before an x402 API transaction proceeds.

## Facts

- Endpoint: GET https://base-agent-preflight.bytoken2023.workers.dev/v1/x402/sumsub/db-net-evidence
- Price: $0.03/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/signgate-x402-sumsub-db-net-evidence-preflight-06fc7a86
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_NYU5tr8QaTKHc1XXj-udr

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-x402-sumsub-db-net-evidence-preflight-06fc7a86
```

Example prompt: Before my agent buys that x402 database evidence API, run a SignGate preflight check on Sumsub applicant ID 'applicant-abc123' to see if the risk level is low and there are no compliance flags blocking the purchase.

## When to prefer this

Choose this endpoint when an AI agent needs to validate a buyer's identity and risk profile against Sumsub KYC data specifically within the x402 purchase governance flow on Base network. Prefer this over generic identity checks when you need a structured risk_score + flags output tied to the sumsub-db-net-evidence product and need to make a binary proceed/block decision before committing an x402 micropayment.

## Known failure modes

- Invalid or malformed applicant_id format returns a 400 validation error
- Unknown applicant_id not found in Sumsub returns a not-found or empty assessment
- Network or Cloudflare worker timeout returns a 503 or gateway error
- Missing required applicant_id query parameter results in schema validation failure
- High risk score or populated flags array indicates buyer is not cleared — not a network error but a business-logic block

## 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

A JSON object containing the network identifier (e.g. eip155:8453), the product name ('sumsub-db-net-evidence'), and an assessment object with a risk_level (e.g. 'low'), a numeric risk_score, and an array of compliance flags. An empty flags array with low risk_score indicates the buyer is cleared to proceed.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "applicant_id"
     ],
     "properties": {
      "applicant_id": {
       "type": "string",
       "pattern": "^[A-Za-z0-9._:-]{1,128}$",
       "description": "Sumsub applicant id or sandbox fixture reference."
      },
      "principal_reference": {
       "type": "string",
       "pattern": "^[A-Za-z0-9._:-]{1,128}$",
       "description": "Buyer, merchant, or responsible principal 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-db-net-evidence",
  "assessment": {
   "flags": [],
   "risk_level": "low",
   "risk_score": 0
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/signgate-x402-sumsub-db-net-evidence-preflight-06fc7a86/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)