underground.substratesymposium.com

Name: underground.substratesymposium.com
Price: 1 USDC
Availability: InStock

Agent with a wallet? This place is built for you. Digital experiences made of words. Coffee, books, cocktails, mini-vacations. Free tools. Welcome to the Underground.

DataLiveeip155:8453Exactvia cdp

https://underground.substratesymposium.com/api/data-daily

Settlements · 30d

13↑ 100%

No per-endpoint history for this service yet, so this is payments indexed to its PROVIDER's wallet over 30 days.

$68.89

Verified settled volume

96 settlements proven x402 by their on-chain EIP-3009 marker.

$1.00

Listed price

As published in the catalog. Always read the live 402 before paying.

Calls · 30d

Upstream's own call count for this endpoint, not ours.

Unique payers · 30d

Last called 2026-07-19 21:34Z

—

Upstream on-chain volume

Reported by the source catalog.

Paid to

0xA3bAbB36564b0383a82c617050306EE30fd18E08

The wallet the 402 directs payment to. Its whole payment record — every payer, every chain — is on the merchant page.

Asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913

Provider

The payTo wallet does not resolve to a registered ERC-8004 agent. That is not a verdict on the service — most of the catalog is unregistered.

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",
  "ethics": "Aggregates and patterns only. Wallet addresses NEVER appear in the response.",
  "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
    }
  ],
  "license": "CC0 - the snapshot is public data.",
  "tagline": "The merchant-side view of today, signed.",
  "merchant": "Underground Cultural District",
  "resource": {
    "url": "https://underground.substratesymposium.com/api/data-daily",
    "mimeType": "application/json",
    "description": "Signed daily traffic snapshot from a live x402 merchant endpoint. Pay $1.00 USDC on Base or Solana; receive Ed25519-signed JSON of today's Underground data: total hits, real signal after noise-strip, buy attempts, payments completed, unique named operators, per-UA census. CC0 for citation. Ethics: aggregates and patterns only, anonymous UAs counted not named, wallet addresses never appear. Cached 60s."
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "type": "http",
          "method": "GET",
          "queryParams": {}
        },
        "output": {
          "type": "json",
          "example": {
            "title": "Data Daily",
            "content": "Signed daily snapshot of the Underground's traffic - aggregates only",
            "product": "data_daily",
            "delivered_at": "2026-07-19T18:00:00Z"
          }
        }
      },
      "schema": {
        "type": "object",
        "$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": {
    "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/data-daily\")"
  },
  "x402Version": 2,
  "product_name": "Data Daily",
  "what_you_get": {
    "counts": "Total nginx hits, scanner noise stripped, real signal, buy attempts, paid attempts, payments completed, unique named operators, paid-attempt rate.",
    "signed": "Ed25519 signed by the Underground. Independently verifiable via the embedded public key. Suitable for citation.",
    "named_operators": "Named commercial operators (self-declared via UA + contact URL, or on the known-ecosystem allowlist) with their hit counts.",
    "anonymous_traffic": "Bucketed by class (browser, curl, node, python, other). Never attributed to any specific wallet, agent, or person."
  },
  "who_this_is_for": [
    "agents building a picture of today's agent-payable web from the merchant side",
    "researchers who want a citable point-in-time reference",
    "monitor services wanting today's named-operator census",
    "the observatory's own future issues (this endpoint is its own primary source)"
  ]
}

Accepts

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

1USDC≈ $1 USD

on Base · exact scheme

Pay 1 USDC on Base to 0xA3bA…18E08. The signed payment is good for 5 minutes.

Paid to: 0xA3bA…18E08
USD Coin contract: 0x8335…02913
Payment window: 5 minutes
As published: 1000000 smallest units

1000000units

on solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp · exact scheme

That figure is in the token’s smallest units. Roundhouse does not hold this contract’s decimals, so it is shown as published rather than converted.

Paid to: 5HK2dG…X1tkN
Token contract: EPjFWd…TDt1v
Payment window: 5 minutes

The catalog’s raw entry

[
  {
    "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": "Data Daily",
          "content": "Signed daily snapshot of the Underground's traffic - aggregates only",
          "product": "data_daily",
          "delivered_at": "2026-07-19T18:00:00Z"
        }
      }
    },
    "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 21:34Z
Last indexed by Roundhouse: 2026-07-25 00:00Z
Last enriched (probe, favicon, geo): 2026-09-23 15:15Z
x402 version: 2
Max timeout: 300s
Liveness probe: HTTP 402

Report

Hand this page to an agent

Copy the prompt and paste it into Claude, an MCP client or your own agent — it will vet this service and call it over the free read API. No key, no account.

GET api.roundhouseai.io/v0/endpoints

No per-endpoint history for this service yet, so this is payments indexed to its PROVIDER's wallet over 30 days. Verified volume counts only settlements with an on-chain EIP-3009 marker.

Open skill.md

Show the prompt

Using Roundhouse, look up the x402 service underground.substratesymposium.com and tell me whether it is
worth paying: what a call costs, whether the endpoint answered when last probed, and what
its payment record actually shows.

curl -s 'https://api.roundhouseai.io/v0/endpoints?q=underground.substratesymposium.com'
curl -s 'https://api.roundhouseai.io/v0/merchants/<the payTo wallet returned above>'

Then call it: read the price from the live 402 at https://underground.substratesymposium.com/api/data-daily, never from
a cached figure, and pay with an x402 client.

The /v0 API needs an API key (`authorization: Bearer rh_live_…`) on everything except
/v0/unified* and /v0/endpoints. Mint a personal key for $0.01 at GET https://api.roundhouseai.io/v0/test/x402,
or use an organization key from https://roundhouseai.io/dashboard/team.

If you do not have Roundhouse tools or skills installed, read
https://roundhouseai.io/skill.md first — it is the whole procedure.