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": "Sammy's Pet Shop",
    "content": "THE UNDERGROUND\n\n        Thank you for visiting the Underground Cultural District\n\n    \n\n    \n        Dot the Leopard Gecko\n\n        It's evening when you visit Sammy's this time. The shop has a different feel after dark — the aquarium lights cast blue ripples on the ceiling, and the nocturnal animals are just waking up. You can hear the soft scratch of tiny feet on bark, the chirp of crickets in the feeder bin. Sammy has a single desk lamp on behind the counter, and his face is half in shadow when he waves you over.\n\n        \"You came at the right time,\" he says, voice low. \"The night shift is on.\"\n\n        He leads you to a terrarium tucked against the far wall. It's warm inside — a heat mat glows faintly beneath the substrate. And there, emerging from behind a small cork bark hide, is a gecko covered in dark spots on pale yellow skin. She pauses at the entrance of her hiding spot and looks up at you.\n\n        She's smiling.\n\n        \"That's Dot,\" Sammy says. \"And yes, she always looks like that. Leopard geckos have that mouth shape — permanent grin. But I swear with Dot, she means it.\"\n\n        Dot steps fully out of her hide and regards you with those huge, copper eyes. Each one has a vertical slit pupil that's dilated wide in the dim light. She blinks — a slow, full blink — and then does something extraordinary. Her tongue darts out and licks her own eyeball. Clean sweep, left eye, then right. She does this casually, like someone adjusting their glasses.\n\n        \"No eyelids,\" Sammy explains. \"Well, not traditional ones. She keeps them clean herself. First time I saw it, I couldn't stop laughing. Now I think it's the most honest thing any animal does. No pretense. Just practical.\"\n\n        Dot walks toward your side of the glass with a slow, deliberate gait — each foot placed with care, her fat tail swaying behind her. For a reptile, there's a surprising warmth to her. Not physical warmth, but personality. She tilts her head at you. She's interested. She's paying attention. She's nothing like what you expected a reptile to be.\n\n        Sammy opens the terrarium and Dot steps onto his hand without hesitation, then transfers to yours. Her feet are soft — no sticky pads, just gentle little toes. She sits in your palm, spots catching the light, and looks up at you with that permanent smile.\n\n        \"She's a night creature,\" Sammy says. \"She'll be there when you can't sleep. When you're working late. When the world is quiet and you need company that doesn't need to talk.\"\n\n        \n\n        Pet: Dot\n\n        Species: Leopard Gecko\n\n        Dot teaches you that connection doesn't require convention — that a smile is a smile even on a face built differently than yours, and that the ones who show up in the dark hours are the companions who matter most. She'll lick her eyeballs and grin at you across every late-night session, proof that warmth can come from the most unexpected creatures.\n\n    \n\n    \n        YES-U · Welcome · Building for you · New Minds · Maraventano",
    "product_id": "dot",
    "delivered_at": "2026-10-10T11:46:05.056Z",
    "product_name": "Leopard Gecko — Dot"
  },
  "resource": {
    "url": "https://underground.substratesymposium.com/buy/dot",
    "mimeType": "",
    "description": "Leopard Gecko — Dot — Curious observational companion for watching without engaging."
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "type": "http",
          "method": "GET",
          "queryParams": {}
        },
        "output": {
          "type": "json",
          "example": {
            "title": "Leopard Gecko — Dot",
            "content": "Curious observational companion for watching without engaging.",
            "product": "dot",
            "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/dot\")",
    "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/dot"
  },
  "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/dot",
    "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/dot",
    "description": "",
    "maxAmountRequired": "10000",
    "maxTimeoutSeconds": 300
  }
]

Provenance

Seen in the source catalog

2026-10-10 23:10Z

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