# Quack AI Q402 Agent Trust Check

> Quack AI Q402 Agent Trust Check is a paid API for AI agents from q402.quackai.ai, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-10).

Looks up the trust profile and on-chain reputation of an EVM wallet address, returning risk flags, ERC-8004 identity registration status, and recent transaction activity.

## Facts

- Endpoint: GET https://q402.quackai.ai/api/x402/agent-trust/%7Baddress%7D
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-10
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/quack-ai-q402-agent-trust-check-39a66958
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_e3ecIK426DtAt9K7IEZ1X

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 quack-ai-q402-agent-trust-check-39a66958
```

Example prompt: Can you check the trust profile and risk flags for the wallet address 0x70997970C51812dc3A010C7d01b50e0d17dc79C8 before I send payment — I want to know if it has an ERC-8004 identity and any recent on-chain activity on Base?

## When to prefer this

Choose this endpoint when you need a fast, pay-per-call trust and identity check for any EVM wallet address, especially when you need ERC-8004 identity registry status combined with on-chain activity signals and risk flags in a single response. Prefer this over building your own on-chain queries when you want a pre-packaged risk assessment without managing RPC connections or gas costs.

## Known failure modes

- Invalid or malformed EVM address returns an error
- Address with no on-chain history may return empty activity and null reputation
- ERC-8004 registry query failure on BSC or Base returns partial data
- Payment failure or insufficient USDC balance prevents the call from completing
- Network RPC downtime may cause on-chain activity lookup to fail

## How this service works

Q402 is a gasless payment protocol for EVM chains. Your users pay zero gas. You sponsor it, invisibly and instantly.

## Output

Returns a JSON object containing: the wallet address, payment timestamp, a receipt ID, the USDC price charged, ERC-8004 identity registration status and registration list from BSC and Base, recent on-chain transaction activity bucket (e.g. 10-49 txns in last 900 blocks), whether recent activity was detected, and an array of risk flags each with a flag name, evidence string, and severity level. Reputation field may be null if no reputation data is available.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "properties": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "paidAt": "2026-08-19T05:00:00.000Z",
  "address": "0x70997970C51812dc3A010C7d01b50e0d17dc79C8",
  "erc8004": {
   "source": "ERC-8004 IdentityRegistry — BSC (0x8004A169FB4a3325136EB29fA0ceB6D2e539a432) and Base queried",
   "isRegistered": false,
   "registrations": []
  },
  "receipt": "atx_a3b4c5d6e7f8a9b0c1d2e3f4",
  "priceUsdc": 0.02,
  "riskFlags": [
   {
    "flag": "no_8004_identity",
    "evidence": "ERC-8004 IdentityRegistry queried on BSC (0x8004A169FB4a3325136EB29fA0ceB6D2e539a432) and Base — balanceOf returned 0",
    "severity": "low"
   }
  ],
  "reputation": null,
  "onChainActivity": {
   "source": "Base mainnet eth_getTransactionCount (public RPC; scan window 900 blocks ≈ 30 min)",
   "txCountBucket": "10-49",
   "recentActivityDetected": true,
   "recentActivityWindowBlocks": 900
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/quack-ai-q402-agent-trust-check-39a66958/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from q402.quackai.ai](https://www.zero.xyz/host/q402.quackai.ai/llms.txt)