# Parallax Co-Purchase Analysis

> Parallax Co-Purchase Analysis is a paid API for AI agents from parallax402.com, paid per call via x402, $0.05/call, status unknown (last checked 2026-09-14).

Returns co-purchase analytics for a single x402 seller: how many of its buyers also pay other sellers, the top 10 co-sellers by shared buyers, and the lift of each association.

## Facts

- Endpoint: GET https://parallax402.com/v1/basket
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/parallax-co-purchase-analysis-ef18fcfa
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_kJoQqAtsFZ9zVYBkFtHJh

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 parallax-co-purchase-analysis-ef18fcfa
```

Example prompt: Pull the co-purchase basket analysis for the seller at payTo address 0xAbC123... — I want to see what share of its buyers also shop elsewhere and which sellers rank highest by shared buyers and lift.

## When to prefer this

Use this endpoint when you need quantified market basket / co-purchase data grounded in actual x402 settlement graph transactions for a specific seller — not estimates or surveys. Prefer it over generic analytics when you need lift-scored, ranked co-seller associations backed by on-chain payment data with explicit coverage and freshness metadata.

## Known failure modes

- Missing or unrecognized seller address/hostname returns an error or empty result
- Seller has too few buyers within the indexed window for meaningful co-purchase statistics
- Rate limiting or payment failure over x402 protocol returns 402 or 429
- Malformed seller parameter (not a valid payTo address or hostname) causes validation failure
- Seller exists but has no co-purchasing signal in the current indexed window

## How this service works

Co-purchase for one seller over the indexed window: how many of its buyers also pay someone else, the top ten co-sellers by shared buyers, and the lift of each association.

## Output

A JSON envelope containing: as_of timestamp, frame, coverage, method, attribution, tier, and window_days metadata, plus a fact object with the seller's total buyer count, multi_seller_share (fraction of buyers who pay at least one other seller), and a ranked list of up to 10 co-sellers each with shared_buyer count and lift score.

## 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",
    "queryParams"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "type": "string",
     "const": "GET"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "seller"
     ],
     "properties": {
      "seller": {
       "type": "string",
       "description": "the seller whose buyers are being looked up, as its payTo address or one of its hostnames"
      }
     },
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type",
    "format"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "json"
    },
    "format": {
     "type": "string",
     "const": "application/json",
     "description": "the basket envelope: as_of, frame, coverage, method, attribution, tier, window_days and a fact carrying buyers, multi_seller_share and the top co-sellers with shared_buyers and lift"
    },
    "example": {
     "type": "object",
     "description": "a worked response, shortened — the shape a full answer has"
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/parallax-co-purchase-analysis-ef18fcfa/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from parallax402.com](https://www.zero.xyz/host/parallax402.com/llms.txt)