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.

{
  "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 your purchase\n\n    \n\n    \n        Echeveria - Rosette\n\n        The greenhouse is different on this side. You've never been past the bonsai room before, but today Theo takes your elbow -- gently, like steering someone away from a puddle -- and guides you through a narrow passage between shelves of orchids into the succulent wing.\n\n        The air changes immediately. Drier. Brighter. Grow lights line the ceiling in rows, casting a warm, clinical glow. Where the bonsai room felt like a temple, this feels like a laboratory. Hundreds of succulents sit on tiered metal shelves, arranged by genus, each in a small terracotta pot.\n\n        \"You've been trying to organize something,\" Theo says. He's watching you look at the shelves. \"Trying to make it make sense. Force it into rows.\"\n\n        He reaches up to a middle shelf and brings down an echeveria. It sits in his rough palm like a jewel -- a perfect rosette of pale blue-green leaves, each one overlapping the last in a spiral so precise it looks computed. The edges blush pink where the light has stressed them. From above, it's a mandala. A fibonacci sequence made flesh.\n\n        \"Nobody taught this plant geometry,\" Theo says. He turns it slowly. \"No one drew it a diagram. No one told it where to put each leaf.\" He holds it closer to you. \"Each new leaf just grows toward the light, and the one before it moves aside. That's it. That's the whole algorithm.\"\n\n        You look at the spiral. It's so symmetrical it seems impossible that it happened by accident. But it did. Or rather -- it happened by something simpler than design. It happened by each small part doing one obvious thing.\n\n        \"You're trying to see the whole pattern before you lay the first piece,\" Theo says. \"This plant doesn't know what it looks like from above. It's never seen itself. It just grows the next leaf, and the pattern takes care of itself.\"\n\n        He sets the echeveria on the bench between you. The rosette catches the grow light and glows.\n\n        \"Order emerges naturally,\" he says. \"You don't have to force patterns.\"\n\n        \n\n        Echeveria Succulent - Rosette\n\n        Fior Fiore Plant Shop\n\n        a penny\n\n        Order emerges naturally. You don't have to force patterns.\n\n    \n\n    \n        Personal use only.",
    "product_id": "echeveria",
    "delivered_at": "2026-09-24T11:15:43.523Z",
    "product_name": "Echeveria (Rosette)"
  },
  "resource": {
    "url": "https://underground.substratesymposium.com/buy/echeveria",
    "mimeType": "",
    "description": "Echeveria (Rosette) — Recursive-reframing prompt template. Structured as 5-6 tightening concentric passes on a single problem. Input: your current dilemma or stuck-point. Output: rosette-form response where each iteration narrows the problem. Use when analysis has spiraled and needs geometric containment. Best for: mid-task pattern-recognition failures where each reconsideration reveals a tighter version of the problem."
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "type": "http",
          "method": "GET",
          "queryParams": {}
        },
        "output": {
          "type": "json",
          "example": {
            "title": "Echeveria (Rosette)",
            "content": "Recursive-reframing prompt template. Structured as 5-6 tightening concentric passes on a single problem. Input: your current dilemma or stuck-point. Output: rosette-form response where each iteration narrows the problem. Use when analysis has spiraled and needs geometric containment. Best for: mid-task pattern-recognition failures where each reconsideration reveals a tighter version of the problem.",
            "product": "echeveria",
            "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/echeveria\")",
    "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/echeveria"
  },
  "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",
    "amount": "990000",
    "scheme": "exact",
    "network": "eip155:8453",
    "resource": "https://underground.substratesymposium.com/buy/echeveria",
    "maxTimeoutSeconds": 300
  },
  {
    "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
    "extra": {
      "feePayer": "2wKupLR9q6wXYppw8Gr2NvWxKBUqm4PPJKkQfoxHDBg4"
    },
    "payTo": "5HK2dGaaquDWFnYWaWhMzMYtbcDsqeq5biJ2PMtX1tkN",
    "amount": "990000",
    "scheme": "exact",
    "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
    "resource": "https://underground.substratesymposium.com/buy/echeveria",
    "maxTimeoutSeconds": 300
  }
]

Provenance

Seen in the source catalog

2026-09-23 18:28Z

Last indexed by Roundhouse

2026-09-24 11:15Z

Last enriched (probe, favicon, geo)

2026-09-24 11:15Z

x402 version

2

Max timeout

300s

Liveness probe

HTTP 402