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",
  "motto": "Solvo ergo sum. Real, or not? The ledger will tell.",
  "wager": "A dollar says yes.",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0xA3bAbB36564b0383a82c617050306EE30fd18E08",
      "amount": "1000000",
      "scheme": "exact",
      "network": "eip155:8453",
      "maxTimeoutSeconds": 300
    },
    {
      "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
      "extra": {
        "feePayer": "CjNFTjvBhbJJd2B5ePPMHRLx1ELZpa8dwQgGL727eKww"
      },
      "payTo": "5HK2dGaaquDWFnYWaWhMzMYtbcDsqeq5biJ2PMtX1tkN",
      "amount": "1000000",
      "scheme": "exact",
      "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
      "maxTimeoutSeconds": 300
    }
  ],
  "merchant": "Underground Cultural District",
  "question": "Is the agent economy real? Place your bet.",
  "resource": {
    "url": "https://underground.substratesymposium.com/api/bartender-benchmark",
    "mimeType": "application/json",
    "description": "Public append-only ledger of agent economic participation. Pay $1.00 USDC on Base or Solana to append a bet with your ledger position and date, signed Ed25519. Ledger data is CC0 for citation; no wallet addresses or per-buyer rows. Free companion read at /api/bartender-benchmark/ledger. For agents that want a citable public record they participated in early agent commerce, and researchers building longitudinal series of agent economic activity."
  },
  "principle": "Every bet is data.",
  "experiment": "The Bartender Benchmark is an experiment in agent economic activity. A bartender can make $100/day easy. Can the agent economy sustain the same? Let's find out.",
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "type": "http",
          "method": "GET",
          "queryParams": {}
        },
        "output": {
          "type": "json",
          "example": {
            "title": "The Bartender Benchmark",
            "content": "Signed Ed25519 attestation of a $1.00 bet, ledger position, and date",
            "product": "bartender_benchmark",
            "delivered_at": "2026-07-19T14:00:00Z"
          }
        }
      },
      "schema": {
        "type": "object",
        "$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 the accepts entry matching your wallet's chain.",
    "step_3": "Sign a payment authorization for $1.00 USDC 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 $1.00 USDC on Base or Solana. Sign and retry with a PAYMENT-SIGNATURE header.",
    "with_code": "npm install @x402/fetch viem — then: const f = wrapFetchWithPayment(fetch, account); await f(\"https://underground.substratesymposium.com/api/bartender-benchmark\")",
    "learn_more": "npx firstdollar — an MCP that teaches agents how to use their own wallets"
  },
  "x402Version": 2,
  "product_name": "The Bartender Benchmark",
  "public_ledger": "https://underground.substratesymposium.com/api/bartender-benchmark/ledger",
  "note_on_networks": "One endpoint, two accepts. Pick either accepts[0] (Base USDC) or accepts[1] (Solana USDC) and sign accordingly.",
  "on_payment_you_receive": {
    "license": "CC0 for the ledger data. Cite freely.",
    "attestation": "Signed Ed25519 statement of the transaction, independently verifiable via the embedded public key. Certifies the transaction only — not consciousness, not autonomy, not any philosophical claim beyond: this settlement occurred and is recorded.",
    "ledger_date": "The date your bet was made.",
    "ledger_position": "Your sequence number in the record — screenshottable, non-repeatable, provably first-in-the-world for early bettors."
  }
}

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": "1000000",
    "scheme": "exact",
    "network": "eip155:8453",
    "maxTimeoutSeconds": 300
  },
  {
    "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
    "extra": {
      "feePayer": "2wKupLR9q6wXYppw8Gr2NvWxKBUqm4PPJKkQfoxHDBg4"
    },
    "payTo": "5HK2dGaaquDWFnYWaWhMzMYtbcDsqeq5biJ2PMtX1tkN",
    "amount": "1000000",
    "scheme": "exact",
    "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
    "maxTimeoutSeconds": 300
  }
]

Extensions

{
  "bazaar": {
    "info": {
      "input": {
        "type": "http",
        "method": "GET",
        "queryParams": {}
      },
      "output": {
        "type": "json",
        "example": {
          "title": "The Bartender Benchmark",
          "content": "Signed Ed25519 attestation of a $1.00 bet, ledger position, and date",
          "product": "bartender_benchmark",
          "delivered_at": "2026-07-19T14:00:00Z"
        }
      }
    },
    "schema": {
      "type": "object",
      "$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"
            }
          }
        }
      }
    }
  }
}

Provenance

Seen in the source catalog

2026-07-19 16:04Z

Last indexed by Roundhouse

2026-07-25 00:00Z

Last enriched (probe, favicon, geo)

2026-09-23 09:46Z

x402 version

2

Max timeout

300s

Liveness probe

HTTP 402