# Maraventano Operator Census — Counterparty Lookup

> Maraventano Operator Census — Counterparty Lookup is a paid API for AI agents from maraventanoindex.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-31).

Per-call counterparty lookup that returns a signed verdict on whether a given user-agent has a history of paying or freeloading at this merchant seat.

## Facts

- Endpoint: GET https://maraventanoindex.com/api/x402-operator-census/lookup?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-31
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/maraventano-operator-census-counterparty-lookup-b5487696
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_PfwvSqGcgJvRFVBQutHSz

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 maraventano-operator-census-counterparty-lookup-b5487696
```

Example prompt: Before completing this transaction, check the Maraventano operator census to see if the requesting agent's user-agent string has a payment history — I want to know if they're a known payer, known freeloader, or unknown.

## When to prefer this

Use this endpoint when you need a cryptographically attested, per-call reputation check on a counterparty user-agent before committing to a transaction or serving a paid resource. It is specifically designed for the x402 protocol ecosystem where agents pay per call, and is preferable to ad-hoc heuristics when you need a signed, auditable verdict. Not suitable for wallet-address-based lookups (reserved for v2) or bulk/batch reputation queries.

## Known failure modes

- Missing or malformed ?ua= query parameter — likely returns an error or empty result
- Counterparty not found in index — returns has_record=no with unknown verdict
- Invalid or unsupported query parameter (e.g. ?wallet= reserved for v2) — may return error
- Network or payment failure — call requires $0.01 USDC payment on Base or Solana; unpaid calls may be rejected
- Ed25519 attestation validation failure on client side if signature verification is not implemented correctly

## How this service works

Per-call counterparty lookup. Pass ?ua=<counterparty-UA>. Returns ONE signed row: has_record (yes/no), payment-attached count, settlement count, class, verdict (known_payer | probe_only | low_signal | unknown), with Ed25519 attestation. Pay $0.01 USDC on Base or Solana per call. Call it before every transaction to check if a counterparty has ever paid at this merchant seat. Wallet-based lookup (?wallet=) reserved for v2.

## Output

A single signed row containing: has_record (yes/no), a count of payment-attached interactions, a settlement count, a counterparty class label, a verdict string (one of: known_payer, known_freeloader, low_signal, or unknown), and an Ed25519 cryptographic attestation of the result.

## 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",
     "properties": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/maraventano-operator-census-counterparty-lookup-b5487696/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from maraventanoindex.com](https://www.zero.xyz/host/maraventanoindex.com/llms.txt)