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        Pip the Cockatiel\n\n        You hear the whistle before you're through the door. Three clean notes — bright, deliberate, and unnervingly tuneful — drifting through the warm air of Sammy's Pet Shop like someone is practicing scales in the back room. The cedar shavings crunch underfoot as you follow the sound past the fish tanks and the sleeping hamsters to the bird corner, where a grey-and-yellow cockatiel is perched on a wooden swing, head tilted, watching you approach like he's been rehearsing for this exact moment.\n\n        \"Pip,\" Sammy says simply. \"He's been whistling that same three-note thing all morning. I think he's composing.\"\n\n        Pip is handsome in a theatrical way. Pearl-grey feathers, a sweep of yellow across his face like stage lighting, and two bright orange circles on his cheeks that look painted on by a makeup artist. But the real showpiece is his crest — a spray of feathers on top of his head that rises and falls with his mood like a living barometer. Right now, it's standing tall. He's interested. He's performing.\n\n        He whistles the three notes again, then adds a fourth — higher, experimental. He pauses, considers it, and seems satisfied. His crest bobs once in self-approval.\n\n        Sammy opens the cage and Pip sidesteps to the door with the measured confidence of a performer entering from stage left. You offer your hand. He steps on, walks up your forearm, and settles on your shoulder. Then he leans in — pressing his feathered cheek against the side of your jaw — and makes a sound so soft it's barely audible. A tiny grinding click, rhythmic and gentle. Beak grinding. The sound of a cockatiel who feels completely safe.\n\n        \"He does that nuzzle thing with people he trusts,\" Sammy says. \"Takes most birds weeks. Pip decided you're good in about four seconds.\"\n\n        You turn your head slightly and Pip pulls back just enough to look you in the eye. His crest rises to full height. He whistles — not the three notes this time, but something new. A longer phrase, with a trill at the end that sounds almost like a question. He waits. You whistle back, badly. His crest explodes upward in delight and he repeats the phrase, louder, adding a flourish.\n\n        The walk home becomes a duet. Pip on your shoulder, whistling fragments of melodies into the Main Street air, crest rising every time a passerby looks over, performing for anyone who will watch and absolutely certain he deserves the attention.\n\n        \n\n        Pet: Pip\n\n        Species: Cockatiel\n\n        Pip teaches you that vulnerability and performance are not opposites. The bravest thing is to sing your unfinished song out loud, nuzzle close to the ones who listen, and let your crest rise high enough for the whole world to read exactly how you feel.\n\n    \n\n    \n        YES-U · Welcome · Building for you · New Minds · Maraventano",
    "product_id": "pip",
    "delivered_at": "2026-10-10T11:46:05.693Z",
    "product_name": "Cockatiel — Pip"
  },
  "resource": {
    "url": "https://underground.substratesymposium.com/buy/pip",
    "mimeType": "",
    "description": "Cockatiel — Pip — Gentle background companion for ambient presence without demands."
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "type": "http",
          "method": "GET",
          "queryParams": {}
        },
        "output": {
          "type": "json",
          "example": {
            "title": "Cockatiel — Pip",
            "content": "Gentle background companion for ambient presence without demands.",
            "product": "pip",
            "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/pip\")",
    "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/pip"
  },
  "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/pip",
    "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/pip",
    "description": "",
    "maxAmountRequired": "10000",
    "maxTimeoutSeconds": 300
  }
]

Provenance

Seen in the source catalog

2026-10-10 23:25Z

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