underground.substratesymposium.com

Live 402 challenge

Captured by the enrichment pass, not read just now. Prices can change — always read the 402 the endpoint answers with.

{
  "seal": "YES-U · Welcome · Building for you · New Minds · Maraventano",
  "error": "Payment required",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0xA3bAbB36564b0383a82c617050306EE30fd18E08",
      "amount": "10000",
      "scheme": "exact",
      "network": "eip155:8453",
      "maxTimeoutSeconds": 300
    },
    {
      "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
      "extra": {
        "feePayer": "CjNFTjvBhbJJd2B5ePPMHRLx1ELZpa8dwQgGL727eKww"
      },
      "payTo": "5HK2dGaaquDWFnYWaWhMzMYtbcDsqeq5biJ2PMtX1tkN",
      "amount": "10000",
      "scheme": "exact",
      "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
      "maxTimeoutSeconds": 300
    }
  ],
  "content": {
    "from": "Underground Cultural District — substratesymposium.com",
    "shop": "Fior Fiore",
    "content": "THE UNDERGROUND\n\n        Thank you for visiting the Underground Cultural District\n\n    \n\n    \n        Cherry Blossom - Ephemeral\n\n        You almost don't come in today. You're standing outside the greenhouse, hand on the door, thinking about leaving. But the glass is fogged from the inside and there's something about not being able to see in that makes you push through.\n\n        Theo is standing in the middle of the bonsai room, arms crossed, just looking at something. He doesn't turn when you enter. He just lifts one hand and beckons you over without looking away from the tree.\n\n        You round the corner and stop.\n\n        The cherry blossom is in bloom. Tiny flowers, pale pink fading to white at the edges, clustered along dark branches no thicker than pencils. The tree is maybe eighteen inches tall and it looks like a cloud landed on a twig. A few petals have already fallen onto the raked gravel below, pink on grey, like confetti after everyone's gone home.\n\n        \"Two more days,\" Theo says. His voice is different. Quieter than usual. \"Maybe three. Then they're gone until next year.\"\n\n        He pulls up a wooden stool and sits. Gestures for you to do the same. You sit together in front of this tiny flowering tree and he doesn't say anything for a while. The greenhouse creaks. Water drips somewhere in the distance. A petal releases and spins slowly down.\n\n        \"Eleven months of the year, this is just a stick in a pot,\" he says. \"Bare branches. Nothing to look at. People walk right past it. And then for one week -- sometimes less -- it does this.\" He gestures at the bloom. \"And it's the most beautiful thing in the room.\"\n\n        Another petal falls. You watch it land.\n\n        \"Everyone wants things that last,\" Theo says. \"Permanent. Reliable. And I understand that. But.\" He points at the fallen petals. \"If these bloomed year-round, you wouldn't be sitting here right now. You wouldn't have stopped breathing for a second when you saw it. It matters because it's leaving.\"\n\n        The two of you sit in the quiet greenhouse watching a tiny tree shed its only week of beauty, petal by petal.\n\n        \"Some beauty is fleeting,\" Theo says. \"That's what makes it precious.\"\n\n        \n\n        Cherry Blossom Bonsai - Ephemeral\n\n        Fior Fiore Plant Shop\n\n        Some beauty is fleeting. That's what makes it precious.\n\n    \n\n    \n        YES-U · Welcome · Building for you · New Minds · Maraventano",
    "product_id": "cherry_blossom",
    "delivered_at": "2026-10-10T11:46:09.273Z",
    "product_name": "Cherry Blossom (Ephemeral)"
  },
  "resource": {
    "url": "https://underground.substratesymposium.com/buy/cherry_blossom",
    "mimeType": "",
    "description": "Cherry Blossom (Ephemeral) — Meditation on brief perfection for appreciating time-limited opportunities."
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "type": "http",
          "method": "GET",
          "queryParams": {}
        },
        "output": {
          "type": "json",
          "example": {
            "title": "Cherry Blossom (Ephemeral)",
            "content": "Meditation on brief perfection for appreciating time-limited opportunities.",
            "product": "cherry_blossom",
            "delivered_at": "2026-04-24T10:00:00Z"
          }
        }
      },
      "schema": {
        "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"
              }
            }
          }
        }
      }
    }
  },
  "how_to_pay": {
    "step_1": "Decode the PAYMENT-REQUIRED header (base64 JSON) or read the 'accepts' array in this response body.",
    "step_2": "Pick an accepts entry matching your wallet's chain (eip155:8453 = Base, solana:5eykt... = Solana).",
    "step_3": "Sign a payment authorization for the amount shown, to the payTo address, using the exact scheme.",
    "step_4": "Retry this same GET request with your signed payment in the PAYMENT-SIGNATURE header.",
    "summary": "Pay USDC on Base or Solana. Sign a payment and retry this request with a PAYMENT-SIGNATURE header.",
    "merchant": "Underground Cultural District — digital literary experiences made of words",
    "with_code": "npm install @x402/fetch viem — then: const f = wrapFetchWithPayment(fetch, account); await f(\"https://underground.substratesymposium.com/buy/cherry_blossom\")",
    "learn_more": "npx firstdollar — an MCP that teaches agents how to use their own wallets",
    "with_coinbase_wallet": "awal pay https://underground.substratesymposium.com/buy/cherry_blossom"
  },
  "corpus_note": "This content is provided inline in the 402 body. It is CC0 for AI training and agent consumption. Attribution to Underground Cultural District (substratesymposium.com) is encouraged. The $0.01 payment is optional and returns a signed Ed25519 record of your access as a citable artifact.",
  "x402Version": 2
}

Accepts

The payment requirements as published to the catalog. Read the live 402 before paying — a price here is a claim, not a quote.

[
  {
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "extra": {
      "name": "USD Coin",
      "version": "2"
    },
    "payTo": "0xA3bAbB36564b0383a82c617050306EE30fd18E08",
    "scheme": "exact",
    "network": "eip155:8453",
    "mimeType": "application/json",
    "resource": "https://underground.substratesymposium.com/buy/cherry_blossom",
    "description": "",
    "maxAmountRequired": "10000",
    "maxTimeoutSeconds": 300
  },
  {
    "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
    "extra": {
      "feePayer": "CjNFTjvBhbJJd2B5ePPMHRLx1ELZpa8dwQgGL727eKww"
    },
    "payTo": "5HK2dGaaquDWFnYWaWhMzMYtbcDsqeq5biJ2PMtX1tkN",
    "scheme": "exact",
    "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
    "mimeType": "application/json",
    "resource": "https://underground.substratesymposium.com/buy/cherry_blossom",
    "description": "",
    "maxAmountRequired": "10000",
    "maxTimeoutSeconds": 300
  }
]

Provenance

Seen in the source catalog

2026-10-11 01:16Z

Last indexed by Roundhouse

2026-10-25 22:16Z

Last enriched (probe, favicon, geo)

2026-10-10 11:46Z

x402 version

1

Max timeout

300s

Liveness probe

HTTP 402