Roundhouse

presign-guard

Is this transaction, token approval or signature safe to sign? Check it before your AI agent or wallet signs it: pre-sign verdict (green/orange/red + reason codes) for EVM and Solana transactions, token approvals and Permit/Permit2/EIP-3009/Seaport signatures. Screens the spender or recipient wallet for OFAC sanctions and scam, phishing or theft reports, and flags unlimited allowances, plain-wallet spenders and risky tokens. Bulk: 100 checks for $0.80 via /v1/credits.

InfraLiveeip155:8453Exactvia cdp
https://presign-guard.fizzl.eu/v1/check
Wallet-securityPre-signApprovalsSanctionsAgents
Calls · 30d
13↑ 219%
This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 31 snapshots so far.
$7.89
Verified settled volume
220 settlements proven x402 by their on-chain EIP-3009 marker.
$0.010
Listed price
As published in the catalog. Always read the live 402 before paying.
13
Calls · 30d
Upstream's own call count for this endpoint, not ours.
7
Unique payers · 30d
Last called 2026-10-26 08:54Z
—
Upstream on-chain volume
Reported by the source catalog.
Paid to
0x6B0F4651eD42893ab58139938175E4a69f175F25

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.

0.01USDC≈ $0.01 USD
on Base · exact scheme

Pay 0.01 USDC on Base to 0x6B0F…75F25. The signed payment is good for 5 minutes.

Paid to
0x6B0F…75F25
USD Coin contract
0x8335…02913
Payment window
5 minutes
As published
10000 smallest units
10000units
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
ATWJ82…aJBH9
Token contract
EPjFWd…TDt1v
Payment window
5 minutes
0.01units
on xrpl:0 · 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
r9xmBs…FGwqw
Token contract
524C55…00000
Payment window
5 minutes
10000units
on algorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73k · 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
LOYVFS…DXAX4
Token contract
31566704
Payment window
5 minutes
100000units
on stellar:pubnet · 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
GCH2J5…J6CDQ
Token contract
CCW67T…JMI75
Payment window
5 minutes
10000units
on eip155:196 · 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
0x6B0F…75F25
Token contract
0x779d…13736
Payment window
5 minutes
The catalog’s raw entry
[
  {
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "extra": {
      "name": "USD Coin",
      "version": "2"
    },
    "payTo": "0x6B0F4651eD42893ab58139938175E4a69f175F25",
    "amount": "10000",
    "scheme": "exact",
    "network": "eip155:8453",
    "maxTimeoutSeconds": 300
  },
  {
    "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
    "extra": {
      "feePayer": "CjNFTjvBhbJJd2B5ePPMHRLx1ELZpa8dwQgGL727eKww"
    },
    "payTo": "ATWJ82T8nRdQwZnaysB68N5EpaSvLRsQP4h6eWmaJBH9",
    "amount": "10000",
    "scheme": "exact",
    "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
    "maxTimeoutSeconds": 300
  },
  {
    "asset": "524C555344000000000000000000000000000000",
    "extra": {
      "issuer": "rMxCKbEDwqr76QuheSUMdEGf4B9xJ8m5De",
      "invoiceId": "presign-guard.fizzl.eu POST /v1/check",
      "sourceTag": 804681468,
      "areFeesSponsored": false
    },
    "payTo": "r9xmBsRr8Ao7jRgjjxreMiAwGiCK2FGwqw",
    "amount": "0.01",
    "scheme": "exact",
    "network": "xrpl:0",
    "maxTimeoutSeconds": 300
  },
  {
    "asset": "31566704",
    "extra": {
      "feePayer": "ZMFK2OI7ZBD2U27ISERZC4S6LKM6WMFJPZQ4MYNJDZ2VNBNMBA67RA22AA"
    },
    "payTo": "LOYVFSQ6ZTS2YWUW4GQ5L6VPP2TPIOXWYDACK53CPOHQQHLDMEMKJDXAX4",
    "amount": "10000",
    "scheme": "exact",
    "network": "algorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73k",
    "maxTimeoutSeconds": 300
  },
  {
    "asset": "CCW67TSZV3SSS2HXMBQ5JFGCKJNXKZM7UQUWUZPUTHXSTZLEO7SJMI75",
    "extra": {
      "areFeesSponsored": true
    },
    "payTo": "GCH2J5UAY24YNKA65MPAATVKWRCZZRZNF3JZKYYS5MIBZPG6U7WJ6CDQ",
    "amount": "100000",
    "scheme": "exact",
    "network": "stellar:pubnet",
    "maxTimeoutSeconds": 300
  },
  {
    "asset": "0x779ded0c9e1022225f8e0630b35a9b54be713736",
    "extra": {
      "name": "USD₮0",
      "version": "1"
    },
    "payTo": "0x6B0F4651eD42893ab58139938175E4a69f175F25",
    "amount": "10000",
    "scheme": "exact",
    "network": "eip155:196",
    "maxTimeoutSeconds": 300
  }
]

Extensions

{
  "bazaar": {
    "info": {
      "input": {
        "body": {
          "type": "approval",
          "token": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
          "amount": "1000000",
          "chainId": 8453,
          "spender": "0x000000000022D473030F116dDEE9F6B43aC78BA3"
        },
        "type": "http",
        "method": "POST",
        "bodyType": "json"
      },
      "output": {
        "type": "json",
        "example": {
          "reasons": [
            {
              "code": "UNLIMITED_APPROVAL",
              "details": {
                "token": "0x833589fcd6edb6e08f4c7c32d4f71b54bda02913"
              },
              "subject": "0x000000000022d473030f116ddee9f6b43ac78ba3",
              "severity": "orange"
            }
          ],
          "verdict": "orange"
        }
      }
    },
    "schema": {
      "type": "object",
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "required": [
        "input"
      ],
      "properties": {
        "input": {
          "type": "object",
          "required": [
            "type",
            "method",
            "bodyType",
            "body"
          ],
          "properties": {
            "body": {
              "type": "object",
              "required": [
                "type"
              ],
              "properties": {
                "to": {
                  "type": "string",
                  "description": "transaction: target contract"
                },
                "tx": {
                  "type": "object",
                  "description": "xrpl: the unsigned transaction JSON"
                },
                "data": {
                  "type": "string",
                  "description": "transaction: 0x-prefixed calldata"
                },
                "from": {
                  "type": "string",
                  "description": "optional: your wallet; an EVM transaction is then simulated"
                },
                "lang": {
                  "enum": [
                    "en",
                    "nl"
                  ],
                  "type": "string",
                  "description": "explain only: en or nl"
                },
                "type": {
                  "enum": [
                    "approval",
                    "transaction",
                    "signature",
                    "authorization",
                    "message",
                    "solana",
                    "xrpl",
                    "algorand",
                    "stellar"
                  ],
                  "type": "string",
                  "description": "What is about to be signed"
                },
                "x402": {
                  "type": "object",
                  "description": "optional, EIP-3009 payments: the x402 accepts entry being paid"
                },
                "nonce": {
                  "type": "string",
                  "description": "authorization, optional: the authorization nonce"
                },
                "token": {
                  "type": "string",
                  "description": "approval: token contract"
                },
                "value": {
                  "type": "string",
                  "description": "transaction: native value in wei"
                },
                "amount": {
                  "type": "string",
                  "description": "approval: amount in base units (0 = revoke)"
                },
                "intent": {
                  "type": "string",
                  "maxLength": 500,
                  "description": "optional: what the agent means to do, in one sentence"
                },
                "method": {
                  "enum": [
                    "personal_sign",
                    "eth_sign"
                  ],
                  "type": "string",
                  "description": "message: personal_sign (default) or eth_sign"
                },
                "origin": {
                  "type": "string",
                  "description": "optional: the site asking (URL or hostname)"
                },
                "address": {
                  "type": "string",
                  "description": "authorization: the contract the EIP-7702 authorization delegates the wallet to ("
                },
                "chainId": {
                  "enum": [
                    1,
                    10,
                    56,
                    137,
                    196,
                    8453,
                    42161,
                    4663,
                    43114
                  ],
                  "type": "integer",
                  "description": "EVM chain; required for approval, transaction and signature"
                },
                "mandate": {
                  "type": "object",
                  "description": "optional, EIP-3009 payments: the spending mandate paid under"
                },
                "message": {
                  "type": "string",
                  "maxLength": 16384,
                  "description": "message: the text or 0x-hex to be signed"
                },
                "network": {
                  "enum": [
                    "xrpl:0",
                    "xrpl:1",
                    "stellar:pubnet",
                    "stellar:testnet"
                  ],
                  "type": "string",
                  "description": "xrpl: xrpl:0 (default) or xrpl:1; stellar: stellar:pubnet (default) or stellar:testnet"
                },
                "spender": {
                  "type": "string",
                  "description": "approval: who gets the allowance"
                },
                "typedData": {
                  "type": [
                    "object",
                    "string"
                  ],
                  "description": "signature: the eth_signTypedData_v4 payload"
                },
                "transaction": {
                  "type": "string",
                  "maxLength": 12000,
                  "description": "solana: base64 wire tx; algorand: base64 msgpack tx; stellar: base64 XDR envelope"
                },
                "transactions": {
                  "type": "array",
                  "items": {
                    "type": "string"
                  },
                  "maxItems": 16,
                  "description": "algorand: an atomic group, each base64 msgpack"
                },
                "authorizationChainId": {
                  "type": "integer",
                  "description": "authorization, optional: the chain id inside the authorization, chainId (default"
                }
              }
            },
            "type": {
              "type": "string",
              "const": "http"
            },
            "method": {
              "enum": [
                "POST"
              ],
              "type": "string"
            },
            "bodyType": {
              "enum": [
                "json",
                "form-data",
                "text"
              ],
              "type": "string"
            }
          },
          "additionalProperties": false
        },
        "output": {
          "type": "object",
          "required": [
            "type"
          ],
          "properties": {
            "type": {
              "type": "string"
            },
            "example": {
              "type": "object",
              "required": [
                "verdict",
                "reasons"
              ],
              "properties": {
                "reasons": {
                  "type": "array",
                  "items": {
                    "type": "object",
                    "required": [
                      "code",
                      "severity"
                    ],
                    "properties": {
                      "code": {
                        "type": "string"
                      },
                      "details": {},
                      "subject": {
                        "type": "string"
                      },
                      "severity": {
                        "enum": [
                          "red",
                          "orange",
                          "info"
                        ],
                        "type": "string"
                      }
                    }
                  }
                },
                "receipt": {
                  "type": "object",
                  "description": "Signed receipt binding this verdict to your request; see openapi.json"
                },
                "subject": {
                  "type": "object"
                },
                "verdict": {
                  "enum": [
                    "green",
                    "orange",
                    "red"
                  ],
                  "type": "string"
                },
                "explanation": {
                  "type": "object",
                  "properties": {
                    "lang": {
                      "type": "string"
                    },
                    "text": {
                      "type": "string"
                    }
                  }
                }
              }
            }
          }
        }
      }
    }
  },
  "builder-code": {
    "info": {
      "a": "bc_pzrclpac"
    },
    "schema": {
      "type": "object",
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "properties": {
        "a": {
          "type": "string",
          "pattern": "^[a-z0-9_]{1,32}$",
          "description": "App builder code"
        },
        "s": {
          "type": "array",
          "items": {
            "type": "string",
            "pattern": "^[a-z0-9_]{1,32}$"
          },
          "maxItems": 11,
          "description": "Service builder codes"
        },
        "w": {
          "type": "string",
          "pattern": "^[a-z0-9_]{1,32}$",
          "description": "Wallet builder code"
        }
      },
      "additionalProperties": false
    }
  },
  "x402-merchant": {
    "info": {
      "logo": "https://fizzl.eu/logo-512.png",
      "name": "Fizzl",
      "website": "https://fizzl.eu",
      "categories": [
        "ai-agents",
        "security",
        "trading-signals",
        "developer-tools",
        "x402",
        "algorand"
      ]
    },
    "schema": {
      "type": "object",
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "required": [
        "name"
      ],
      "properties": {
        "logo": {
          "type": "string"
        },
        "name": {
          "type": "string"
        },
        "website": {
          "type": "string"
        },
        "categories": {
          "type": "array",
          "items": {
            "type": "string"
          }
        }
      }
    }
  }
}

Provenance

Seen in the source catalog
2026-10-29 10:41Z
Last indexed by Roundhouse
2026-10-29 11:00Z
Last enriched (probe, favicon, geo)
2026-10-05 10:15Z
x402 version
2
Max timeout
300s
Liveness probe
HTTP 404
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. 31 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 presign-guard 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=presign-guard'
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://presign-guard.fizzl.eu/v1/check, 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.