Roundhouse

QuickBuild

Balances of one address on Base mainnet in a single call: native ETH, the well-known tokens USDC, USDT, USDbC, DAI, WETH, cbETH, wstETH, AERO (non-zero only, or all with includeZero=true), plus up to 10 extra ERC-20 contracts you pass in `tokens` (symbol/name/decimals read on-chain). Also nonce, account type (EOA, EIP-7702 delegated EOA, or contract) and a USD total for ETH/WETH (Chainlink) and stablecoins. Read live from public Base RPC via Multicall3; cached 10 s. All params optional: defaults to a well-known public address. Invalid input = 400, never charged.

DataLiveeip155:8453Exactvia facilitator:payAI
https://quickbuild.quynguyenbac.workers.dev/api/base/wallet
BaseWalletBalanceCryptoUsdc
Calls · 30d
2
This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 15 snapshots so far.
$0.18
Verified settled volume
26 settlements proven x402 by their on-chain EIP-3009 marker.
$0.0020
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
Never called
—
Upstream on-chain volume
Reported by the source catalog.
Paid to
0x751a4c3841bE287544C371B4EE09Bd3366AeA7cf

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",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0x751a4c3841bE287544C371B4EE09Bd3366AeA7cf",
      "amount": "2000",
      "scheme": "exact",
      "network": "eip155:8453",
      "mimeType": "application/json",
      "resource": "https://quickbuild.quynguyenbac.workers.dev/api/base/wallet",
      "description": "Balances of one address on Base mainnet in a single call: native ETH, the well-known tokens USDC, USDT, USDbC, DAI, WETH, cbETH, wstETH, AERO (non-zero only, or all with includeZero=true), plus up to 10 extra ERC-20 contracts you pass in `tokens` (symbol/name/decimals read on-chain). Also nonce, account type (EOA, EIP-7702 delegated EOA, or contract) and a USD total for ETH/WETH (Chainlink) and stablecoins. Read live from public Base RPC via Multicall3; cached 10 s. All params optional: defaults to a well-known public address. Invalid input = 400, never charged.",
      "outputSchema": {
        "input": {
          "type": "http",
          "method": "GET",
          "queryParams": {
            "address": "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045"
          },
          "discoverable": true
        },
        "output": {
          "type": "json",
          "example": {
            "eth": {
              "usd": 0,
              "wei": "0",
              "balance": "0"
            },
            "nonce": 0,
            "tokens": [
              {
                "raw": "50000",
                "usd": 0.05,
                "symbol": "USDC",
                "address": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
                "balance": "0.05",
                "decimals": 6
              }
            ],
            "address": "0x751a4c3841bE287544C371B4EE09Bd3366AeA7cf",
            "chainId": 8453,
            "totalUsd": 0.05,
            "isContract": false,
            "accountType": "eoa",
            "blockNumber": 52868213
          }
        }
      },
      "maxAmountRequired": "2000",
      "maxTimeoutSeconds": 300
    }
  ],
  "resource": {
    "url": "https://quickbuild.quynguyenbac.workers.dev/api/base/wallet",
    "tags": [
      "base",
      "wallet",
      "balance",
      "crypto",
      "usdc"
    ],
    "mimeType": "application/json",
    "description": "Balances of one address on Base mainnet in a single call: native ETH, the well-known tokens USDC, USDT, USDbC, DAI, WETH, cbETH, wstETH, AERO (non-zero only, or all with includeZero=true), plus up to 10 extra ERC-20 contracts you pass in `tokens` (symbol/name/decimals read on-chain). Also nonce, account type (EOA, EIP-7702 delegated EOA, or contract) and a USD total for ETH/WETH (Chainlink) and stablecoins. Read live from public Base RPC via Multicall3; cached 10 s. All params optional: defaults to a well-known public address. Invalid input = 400, never charged.",
    "serviceName": "QuickBuild"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "type": "http",
          "method": "GET",
          "queryParams": {
            "address": "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045"
          }
        },
        "output": {
          "type": "json",
          "example": {
            "eth": {
              "usd": 0,
              "wei": "0",
              "balance": "0"
            },
            "nonce": 0,
            "tokens": [
              {
                "raw": "50000",
                "usd": 0.05,
                "symbol": "USDC",
                "address": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
                "balance": "0.05",
                "decimals": 6
              }
            ],
            "address": "0x751a4c3841bE287544C371B4EE09Bd3366AeA7cf",
            "chainId": 8453,
            "totalUsd": 0.05,
            "isContract": false,
            "accountType": "eoa",
            "blockNumber": 52868213
          }
        }
      },
      "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",
                "required": [],
                "properties": {
                  "tokens": {
                    "type": "string",
                    "description": "Optional comma-separated extra ERC-20 contract addresses on Base (max 10)."
                  },
                  "address": {
                    "type": "string",
                    "description": "Base address (0x + 40 hex). Optional: defaults to 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 (vitalik.eth)."
                  },
                  "includeZero": {
                    "type": "boolean",
                    "description": "Also list well-known tokens with zero balance (default false)."
                  }
                }
              }
            },
            "additionalProperties": false
          },
          "output": {
            "type": "object",
            "required": [
              "type"
            ],
            "properties": {
              "type": {
                "type": "string"
              },
              "example": {
                "type": "object",
                "properties": {
                  "eth": {
                    "type": "object",
                    "properties": {
                      "usd": {
                        "type": [
                          "number",
                          "null"
                        ]
                      },
                      "wei": {
                        "type": "string"
                      },
                      "balance": {
                        "type": "string"
                      }
                    }
                  },
                  "nonce": {
                    "type": "integer"
                  },
                  "tokens": {
                    "type": "array",
                    "items": {
                      "type": "object",
                      "properties": {
                        "raw": {
                          "type": "string"
                        },
                        "usd": {
                          "type": [
                            "number",
                            "null"
                          ]
                        },
                        "symbol": {
                          "type": [
                            "string",
                            "null"
                          ]
                        },
                        "address": {
                          "type": "string"
                        },
                        "balance": {
                          "type": [
                            "string",
                            "null"
                          ]
                        },
                        "decimals": {
                          "type": [
                            "integer",
                            "null"
                          ]
                        }
                      }
                    }
                  },
                  "address": {
                    "type": "string"
                  },
                  "totalUsd": {
                    "type": "number"
                  },
                  "isContract": {
                    "type": "boolean"
                  },
                  "accountType": {
                    "enum": [
                      "eoa",
                      "eoa-eip7702",
                      "contract"
                    ],
                    "type": "string"
                  },
                  "blockNumber": {
                    "type": "integer"
                  }
                }
              }
            }
          }
        }
      }
    }
  },
  "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.

0.002USDC≈ $0.002 USD
on Base · exact scheme

Pay 0.002 USDC on Base to 0x751a…eA7cf. The signed payment is good for 5 minutes.

Paid to
0x751a…eA7cf
USD Coin contract
0x8335…02913
Payment window
5 minutes
As published
2000 smallest units
The catalog’s raw entry
[
  {
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "extra": {
      "name": "USD Coin",
      "version": "2"
    },
    "payTo": "0x751a4c3841bE287544C371B4EE09Bd3366AeA7cf",
    "amount": "2000",
    "scheme": "exact",
    "network": "eip155:8453",
    "maxTimeoutSeconds": 300
  }
]

Extensions

{
  "bazaar": {
    "info": {
      "input": {
        "type": "http",
        "method": "GET",
        "queryParams": {
          "address": "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045"
        }
      },
      "output": {
        "type": "json",
        "example": {
          "eth": {
            "usd": 0,
            "wei": "0",
            "balance": "0"
          },
          "nonce": 0,
          "tokens": [
            {
              "raw": "50000",
              "usd": 0.05,
              "symbol": "USDC",
              "address": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
              "balance": "0.05",
              "decimals": 6
            }
          ],
          "address": "0x751a4c3841bE287544C371B4EE09Bd3366AeA7cf",
          "chainId": 8453,
          "totalUsd": 0.05,
          "isContract": false,
          "accountType": "eoa",
          "blockNumber": 52868213
        }
      }
    },
    "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",
              "required": [],
              "properties": {
                "tokens": {
                  "type": "string",
                  "description": "Optional comma-separated extra ERC-20 contract addresses on Base (max 10)."
                },
                "address": {
                  "type": "string",
                  "description": "Base address (0x + 40 hex). Optional: defaults to 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 (vitalik.eth)."
                },
                "includeZero": {
                  "type": "boolean",
                  "description": "Also list well-known tokens with zero balance (default false)."
                }
              }
            }
          },
          "additionalProperties": false
        },
        "output": {
          "type": "object",
          "required": [
            "type"
          ],
          "properties": {
            "type": {
              "type": "string"
            },
            "example": {
              "type": "object",
              "properties": {
                "eth": {
                  "type": "object",
                  "properties": {
                    "usd": {
                      "type": [
                        "number",
                        "null"
                      ]
                    },
                    "wei": {
                      "type": "string"
                    },
                    "balance": {
                      "type": "string"
                    }
                  }
                },
                "nonce": {
                  "type": "integer"
                },
                "tokens": {
                  "type": "array",
                  "items": {
                    "type": "object",
                    "properties": {
                      "raw": {
                        "type": "string"
                      },
                      "usd": {
                        "type": [
                          "number",
                          "null"
                        ]
                      },
                      "symbol": {
                        "type": [
                          "string",
                          "null"
                        ]
                      },
                      "address": {
                        "type": "string"
                      },
                      "balance": {
                        "type": [
                          "string",
                          "null"
                        ]
                      },
                      "decimals": {
                        "type": [
                          "integer",
                          "null"
                        ]
                      }
                    }
                  }
                },
                "address": {
                  "type": "string"
                },
                "totalUsd": {
                  "type": "number"
                },
                "isContract": {
                  "type": "boolean"
                },
                "accountType": {
                  "enum": [
                    "eoa",
                    "eoa-eip7702",
                    "contract"
                  ],
                  "type": "string"
                },
                "blockNumber": {
                  "type": "integer"
                }
              }
            }
          }
        }
      }
    }
  }
}

Provenance

Seen in the source catalog
2026-10-20 20:02Z
Last indexed by Roundhouse
2026-10-26 13:16Z
Last enriched (probe, favicon, geo)
2026-10-21 05:45Z
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

This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 15 snapshots so far. 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 QuickBuild 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=QuickBuild'
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://quickbuild.quynguyenbac.workers.dev/api/base/wallet, 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. Either pay over x402 (mint a personal key for $0.01 at
GET https://api.roundhouseai.io/v0/test/x402), or ask me for an organization key, which I create at
https://roundhouseai.io/dashboard/connections. If you have neither, ask before going further.

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