Roundhouse

Xerxes

Returns the total supply of an ERC20 token contract on Ethereum mainnet, as a decimal string. Query: token (ERC-20 contract, 0x + 40 hex).

Infraoffline · HTTP 530eip155:8453Exactvia cdp
https://ari001.tailb4ac3a.ts.net/v1/ventures/ethereum_rpc_api/erc20_total_supply
VentureEthereumTotalSupply
Settlements · 30d
40
No per-endpoint history for this service yet, so this is payments indexed to its PROVIDER's wallet over 30 days.
$0.13
Verified settled volume
40 settlements proven x402 by their on-chain EIP-3009 marker.
$0.0030
Listed price
As published in the catalog. Always read the live 402 before paying.
3
Calls · 30d
Upstream's own call count for this endpoint, not ours.
1
Unique payers · 30d
Last called 2026-09-24 04:33Z
—
Upstream on-chain volume
Reported by the source catalog.
Paid to
0x277ee11C8E4F5A3709C1083fC9b21144Ef103dEa

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.

Accepts

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

0.003USDC≈ $0.003 USD
on Base · exact scheme

Pay 0.003 USDC on Base to 0x277e…03dEa. The signed payment is good for 5 minutes.

Paid to
0x277e…03dEa
USD Coin contract
0x8335…02913
Payment window
5 minutes
As published
3000 smallest units
The catalog’s raw entry
[
  {
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "extra": {
      "name": "USD Coin",
      "version": "2"
    },
    "payTo": "0x277ee11C8E4F5A3709C1083fC9b21144Ef103dEa",
    "amount": "3000",
    "scheme": "exact",
    "network": "eip155:8453",
    "maxTimeoutSeconds": 300
  }
]

Extensions

{
  "bazaar": {
    "info": {
      "input": {
        "type": "http",
        "method": "GET",
        "queryParams": {
          "token": "0xdAC17F958D2ee523a2206206994597C13D831ec7"
        }
      },
      "output": {
        "type": "json",
        "example": {
          "ok": true,
          "chain": "ethereum",
          "method": "totalSupply",
          "result": "1000000",
          "service": "ethereum_rpc_api.erc20_total_supply"
        }
      }
    },
    "schema": {
      "type": "object",
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "required": [
        "input"
      ],
      "properties": {
        "input": {
          "type": "object",
          "required": [
            "type",
            "method"
          ],
          "properties": {
            "type": {
              "type": "string",
              "const": "http"
            },
            "method": {
              "enum": [
                "GET",
                "HEAD",
                "DELETE"
              ],
              "type": "string"
            },
            "queryParams": {
              "type": "object",
              "required": [
                "token"
              ],
              "properties": {
                "token": {
                  "type": "string",
                  "pattern": "^0x[a-fA-F0-9]{40}$",
                  "description": "ERC-20 contract, 0x + 40 hex"
                }
              }
            }
          },
          "additionalProperties": false
        },
        "output": {
          "type": "object",
          "required": [
            "type"
          ],
          "properties": {
            "type": {
              "type": "string"
            },
            "example": {
              "type": "object",
              "required": [
                "ok",
                "service"
              ],
              "properties": {
                "ok": {
                  "type": "boolean"
                },
                "chain": {
                  "type": "string"
                },
                "error": {
                  "type": "string",
                  "description": "present when ok is false"
                },
                "method": {
                  "type": "string"
                },
                "result": {
                  "type": "string",
                  "description": "the uint256 as a decimal string"
                },
                "service": {
                  "type": "string"
                }
              }
            }
          }
        }
      }
    }
  },
  "eip2612GasSponsoring": {
    "info": {
      "version": "1",
      "description": "The facilitator accepts EIP-2612 gasless Permit to Permit2 canonical contract."
    },
    "schema": {
      "type": "object",
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "required": [
        "from",
        "asset",
        "spender",
        "amount",
        "nonce",
        "deadline",
        "signature",
        "version"
      ],
      "properties": {
        "from": {
          "type": "string",
          "pattern": "^0x[a-fA-F0-9]{40}$",
          "description": "The address of the sender."
        },
        "asset": {
          "type": "string",
          "pattern": "^0x[a-fA-F0-9]{40}$",
          "description": "The address of the ERC-20 token contract."
        },
        "nonce": {
          "type": "string",
          "pattern": "^[0-9]+$",
          "description": "The current EIP-2612 nonce of the sender."
        },
        "amount": {
          "type": "string",
          "pattern": "^[0-9]+$",
          "description": "The amount to approve (uint256)."
        },
        "spender": {
          "type": "string",
          "pattern": "^0x[a-fA-F0-9]{40}$",
          "description": "The address of the spender (Canonical Permit2)."
        },
        "version": {
          "type": "string",
          "pattern": "^[0-9]+(\\.[0-9]+)*$",
          "description": "Schema version identifier."
        },
        "deadline": {
          "type": "string",
          "pattern": "^[0-9]+$",
          "description": "The timestamp at which the signature expires."
        },
        "signature": {
          "type": "string",
          "pattern": "^0x[a-fA-F0-9]+$",
          "description": "The 65-byte concatenated signature (r, s, v) as a hex string."
        }
      }
    }
  }
}

Provenance

Seen in the source catalog
2026-09-24 04:33Z
Last indexed by Roundhouse
2026-09-24 09:20Z
Last enriched (probe, favicon, geo)
2026-09-23 15:15Z
x402 version
2
Max timeout
300s
Liveness probe
HTTP 530
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 Xerxes 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=Xerxes'
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://ari001.tailb4ac3a.ts.net/v1/ventures/ethereum_rpc_api/erc20_total_supply, 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.