# Nomos Counterparty Intelligence API

> Nomos Counterparty Intelligence API is a paid API for AI agents from base-agent-preflight.bytoken2023.workers.dev, paid per call via x402, $0.5/call, status unknown (last checked 2026-09-14).

Returns identity, risk score, and behavioral summary for a wallet address based on its on-chain counterparty activity over a specified lookback window.

## Facts

- Endpoint: POST https://base-agent-preflight.bytoken2023.workers.dev/x402/v1/wallet/counterparty-intelligence
- Price: $0.5/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/nomos-counterparty-intelligence-api-d1318a66
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_qvbSBf0Y1EZ_uRxiHE0LT

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 nomos-counterparty-intelligence-api-d1318a66 -d '<json body>'
```

Example prompt: Before I send payment to 0x742d35Cc6634C0532925a3b8D4C9B0F3e5aA1234, can you run a counterparty intelligence check on that Base wallet for the last 14 days and flag any risk concerns?

## When to prefer this

Use this endpoint when an autonomous agent needs a fast, pay-per-request risk and identity preflight check on a wallet address before executing a transaction, approving a payment, or onboarding a counterparty. It is specifically suited for Base and Ethereum wallets, offers bounded lookback windows (1–30 days), and returns structured risk scores with flags — ideal for programmatic go/no-go decisions without requiring a full KYC integration or ongoing subscription.

## Known failure modes

- Invalid wallet address format (must match 0x + 40 hex chars) returns validation error
- Unsupported chain value (only 'ethereum' and 'base' accepted) returns enum error
- lookback_days exceeding 30 or limit exceeding 10 returns schema validation failure
- Insufficient USDC payment (x402 payment not included or underpaid) returns 402 Payment Required
- Wallet with no transaction history in the window may return empty or minimal response
- Network timeouts or upstream data unavailability may result in 5xx errors

## 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, product name, a risk assessment with risk_level (e.g. 'low', 'medium', 'high'), a numeric risk_score, and a flags array listing any specific risk signals. Additional fields may include identity, activity, and provenance objects summarizing behavioral context for the queried wallet.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "chain",
      "address",
      "lookback_days",
      "limit"
     ],
     "properties": {
      "chain": {
       "enum": [
        "ethereum",
        "base"
       ],
       "type": "string",
       "description": "Supported EVM chain for the counterparty summary."
      },
      "limit": {
       "type": "integer",
       "maximum": 10,
       "minimum": 1,
       "description": "Maximum material counterparty categories to return."
      },
      "address": {
       "type": "string",
       "pattern": "^0x[a-fA-F0-9]{40}$",
       "description": "Wallet address to summarize."
      },
      "lookback_days": {
       "type": "integer",
       "maximum": 30,
       "minimum": 1,
       "description": "Lookback window for the bounded summary. Maximum 30 days."
      },
      "idempotency_key": {
       "type": "string",
       "maxLength": 128,
       "description": "Optional caller-supplied idempotency key."
      }
     }
    }
   },
   "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": "nomos-counterparty-intelligence",
  "assessment": {
   "flags": [],
   "risk_level": "low",
   "risk_score": 0
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/nomos-counterparty-intelligence-api-d1318a66/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)