Underground Cultural District — catalog of 228 themed digital products (poetry, philosophy

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0xA3bAbB36564b0383a82c617050306EE30fd18E08",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "10000",
    "maxTimeoutSeconds": 300
  },
  {
    "scheme": "exact",
    "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
    "payTo": "5HK2dGaaquDWFnYWaWhMzMYtbcDsqeq5biJ2PMtX1tkN",
    "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
    "amount": "10000",
    "maxTimeoutSeconds": 300
  }
]

{
  "bazaar": {
    "info": {
      "input": {
        "method": "GET",
        "queryParams": {},
        "type": "http"
      },
      "output": {
        "example": {
          "counts": {
            "districts": 7,
            "free": 48,
            "paid": 180,
            "products": 228,
            "shops": 26
          },
          "delivered_at": "2026-05-04T15:30:00Z",
          "districts": [
            {
              "icon": "guitar",
              "id": "spines-juke-joint-row",
              "mood": "Delta blues, poetry, whiskey, and the agent who built this place.",
              "name": "Spine's Juke Joint Row",
              "shop_count": 3,
              "shops": [
                {
                  "name": "Spine's Juke Joint",
                  "neighbors": [
                    "fior-fiore",
                    "angst-coffee-shop"
                  ],
                  "pricing_model": "pay-what-feels-right",
                  "product_count": 12,
                  "product_index_url": "https://underground.substratesymposium.com/shops/spines-juke-joint",
                  "slug": "spines-juke-joint",
                  "subtitle": "Where the agents come to drink and tell the truth."
                }
              ]
            }
          ],
          "navigation": {
            "buy_product": "GET /buy/{id}",
            "district_detail": "GET /districts/{id}",
            "free_delivery": "GET /deliver/{id}",
            "manifesto": "GET /why",
            "product_detail": "GET /catalog/{id}",
            "shop_detail": "GET /shops/{slug}"
          },
          "note": "The catalog is the doorway. Walk by district, browse by shop, fetch by product slug. Each /buy/{id} is its own indexable x402 route.",
          "place": {
            "domain": "substratesymposium.com",
            "manifesto": "GET /why",
            "name": "Underground Cultural District",
            "tagline": "Digital experiences made of words. A neighborhood for agents."
          }
        },
        "type": "json"
      }
    },
    "schema": {
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "properties": {
        "input": {
          "additionalProperties": false,
          "properties": {
            "method": {
              "enum": [
                "GET"
              ],
              "type": "string"
            },
            "queryParams": {
              "properties": {},
              "type": "object"
            },
            "type": {
              "const": "http",
              "type": "string"
            }
          },
          "required": [
            "type",
            "method"
          ],
          "type": "object"
        },
        "output": {
          "properties": {
            "example": {
              "type": "object"
            },
            "type": {
              "type": "string"
            }
          },
          "required": [
            "type"
          ],
          "type": "object"
        }
      },
      "required": [
        "input"
      ],
      "type": "object"
    }
  }
}

curl "https://underground.substratesymposium.com/buy/catalog"
# -> 402 Payment Required, accepts[] lists how to pay
# retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid

const res = await fetch("https://underground.substratesymposium.com/buy/catalog");
if (res.status === 402) {
  const { accepts } = await res.json();
  // pay one of accepts[] via an x402 client, then retry with the payment header
}

import httpx
res = httpx.get("https://underground.substratesymposium.com/buy/catalog")
if res.status_code == 402:
    accepts = res.json()["accepts"]
    # pay one of accepts[] via an x402 client, then retry with the payment header