●

Second Opinion

Verification PAYMENT-READY

payment-ready until 2026-09-15

Adversarial verification for AI agents: an independent skeptic attempts to refute a claim before the agent acts on it, returning a structured verdict (refuted / supported / inconclusive) with calibrated confidence, findings, and citations. Three tiers: quick reasoning check ($0.03) · single skeptic with live web research ($0.20) · three-skeptic panel with majority vote ($0.75). Every verdict carries an Ed25519-signed receipt verifiable offline against our published key. Accuracy benchmarked on the full public AVeriTeC dev set — 78.2% overall, 95.7% on refuted claims — with method and failures published at secondopinionx402.com/benchmark. Zero-install hosted MCP connector at /mcp; Python client: pip install secondopinion-x402. USDC via x402 on Algorand, Base, and Solana; no accounts, no API keys.

Pay from $0.02 to $0.75 per request in USDC on Base / Polygon / Solana, settled onchain via the x402 protocol, no signup, no API key needed.

BASE URL https://secondopinionx402.com │ WEBSITE https://secondopinionx402.com │ ENDPOINTS 6 │ NETWORK Base / Polygon / Solana │ ASSET USDC │ MEMBER SINCE 2026-07-25 │ MONITORED SINCE 2026-07-25

VERDICT

ranking generation 3

strong 93/100 #17 of 76 in Verification by measured score

What the score read on this service: status online, 100% uptime 30d, 1146ms response p95, x402 compliance 14 of 14, $0.02 price against the category. Each of those is measured, and each is published in full below.

The score comes from our own monitoring, never from reviews, operator claims, or a language model: reliability, x402 compliance, price against the category, a deterministic risk flag, and a small on-chain traction term, weighted by ranking generation 3. It is not placement anyone can buy: the paid verify tier is reported beside it and is not one of its inputs. Every component below stays published and read-only.

It is a score inside Verification, and only there: price and speed are scored against the whole category field, every listing in it that carries no danger flag, the scored service included, which here means 76 listings, this one among them. That set is wider than the 76 the position above is counted against, because a listing we have measured too little of to rank still sits in the field the price and the speed are normalized over. The same service in a different field would read differently. The same engine answers GET /api/v1/best, and asked for a different pool (the whole directory, or another filter) it returns a different number for this service under this same ranking generation. Neither is more correct: they answer different questions, and the methodology states which is which.

Bands on the 0 to 100 measured score: strong at 93 and above, solid from 75, mixed from 55, weak below 55. Price and speed are scored against the whole category field, every listing in it that carries no danger flag, the scored service included, so the score places a service in its own field.

ALTERNATIVES IN VERIFICATION

Other Verification services in this directory, ordered by the same measured score. The figures are ours: 30-day uptime from our own probes, 30-day settlement volume read on-chain (a conservative undercount, and null where we cannot measure it, never a zero).

Ranked alternative x402 services in the same category, with band, measured score, 30-day uptime and 30-day on-chain settlement volume
SERVICE	BAND	SCORE	UPTIME 30D	VOL 30D
Rubric Protocol — Post-Quantum AI Attestation	strong	100	100%	---
scvd.store — evidence observatory for the x402 economy	strong	99	100%	---
10x402	strong	98	100%	---
DNS Doctor	strong	98	100%	---
HostDeFi Token Risk API	strong	98	100%	---

5 of 75 other ranked services in Verification

ASSESSMENT

updated 3h ago

The parts the verdict above is computed from, each with its proof. Click any chip. Measured values stay read-only; unknown is honest, and an unknown is never counted as a zero.

reliability 100%

uptime 24h: 100%
uptime 7d: 100%
uptime 30d: 100%
uptime 90d: 100%
response p95: 1146ms
avg response: 577ms
total checks: 2,757

Measured on the unpaid 402 handshake, not the paid call. A service can 402 correctly and still fail after payment.

compliance A (14/14)

14 of 14 x402 conformance checks pass. Full checklist below.

jump to compliance checklist

price $0.02 to $0.75 (p63 in Verification)

price (min): $0.02
price (max): $0.75
category percentile (min): p63 in Verification
category percentile (max): p74 in Verification
endpoints / prices: 6 / 3
model: tiered
stability: 75%

risk clean

No deterministic risk flag. Risk fires only on an exact blocklist match, or a reserved-brand name with a mismatched verified payTo. Never from low uptime, a high price, or a model guess.

domain age: -
registrar: -
hosting: custom
domain created: ---

Identity facts, not a risk score.

traction ---

This service settles on a network x402-list does not measure yet, so on-chain volume is not counted here. Shown as unmeasured, not zero.

CHANGES

1 in 30d

Payout, price, and schema changes detected on this service's x402 wire. A payout rotation at an unchanged price shows up here even when nothing else moves. Full feed at /changes.

changes schema changed 30d ago (1 in 30d)

schema changed · 30d ago

schema added POST /v1/verify exact eip155:137 0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359 USDC 2 120 {"name":"USD Coin","version":"2"}

schema added POST /v1/verify/async exact eip155:137 0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359 USDC 2 60 {"name":"USD Coin","version":"2"}

schema added POST /v1/verify/panel exact eip155:137 0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359 USDC 2 300 {"name":"USD Coin","version":"2"}

schema added POST /v1/verify/panel/async exact eip155:137 0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359 USDC 2 60 {"name":"USD Coin","version":"2"}

schema added POST /v1/verify/quick exact eip155:137 0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359 USDC 2 60 {"name":"USD Coin","version":"2"}

schema added POST /v1/verify/quick/async exact eip155:137 0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359 USDC 2 60 {"name":"USD Coin","version":"2"}

see all changes for this service

WHAT IT DOES

ai-derived

No AI synthesis has been produced for this service yet.

ENDPOINTS

Service endpoints with HTTP method, path, description, pricing, and network
METHOD	PATH	PRICE	NETWORK	ASSET	402 CHANNEL
POST	/v1/verify	$0.20	Base/Polygon	USDC	header
POST	/v1/verify/async	$0.20	Base/Polygon/Solana	USDC	header
POST	/v1/verify/panel	$0.75	Base/Polygon	USDC	header
POST	/v1/verify/panel/async	$0.75	Base/Polygon/Solana	USDC	header
POST	/v1/verify/quick	$0.02	Base/Polygon	USDC	header
POST	/v1/verify/quick/async	$0.02	Base/Polygon/Solana	USDC	header

6 endpoints

REQUEST / RESPONSE EXAMPLE

An unpaid request to POST /v1/verify returns HTTP 402 with the payment terms. Settle onchain via your facilitator, then retry with the X-Payment header.

// request

curl -i -X POST 'https://secondopinionx402.com/v1/verify'

// 402 response (captured by monitor) · 6 payloads · click to expand

[
  {
    "error": "Payment required",
    "accepts": [
      {
        "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "payTo": "0xa12d480B17797f2401949130bEcBeC24c754ed30",
        "amount": "200000",
        "scheme": "exact",
        "network": "eip155:8453",
        "maxTimeoutSeconds": 120
      },
      {
        "asset": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "payTo": "0xa12d480B17797f2401949130bEcBeC24c754ed30",
        "amount": "200000",
        "scheme": "exact",
        "network": "eip155:137",
        "maxTimeoutSeconds": 120
      },
      {
        "asset": "31566704",
        "extra": {
          "name": "USDC",
          "decimals": 6,
          "feePayer": "ZMFK2OI7ZBD2U27ISERZC4S6LKM6WMFJPZQ4MYNJDZ2VNBNMBA67RA22AA"
        },
        "payTo": "X4BGQO53SBYIPXGE22E3C4BXJZKYKUYG3PZQVDBNUIVB64D6K7MEVGGCSM",
        "amount": "200000",
        "scheme": "exact",
        "network": "algorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73ktiC1qzkkit8=",
        "maxTimeoutSeconds": 120
      }
    ],
    "resource": {
      "url": "https://secondopinionx402.com/v1/verify",
      "mimeType": "application/json",
      "description": "Second Opinion: an independent adversarial agent attempts to refute your claim (live web research) and returns a structured verdict with citations."
    },
    "extensions": {
      "bazaar": {
        "info": {
          "input": {
            "body": {
              "type": "object",
              "required": [
                "claim"
              ],
              "properties": {
                "claim": {
                  "type": "string",
                  "maxLength": 2000,
                  "minLength": 8
                },
                "context": {
                  "type": "string",
                  "maxLength": 4000
                },
                "claimed_sources": {
                  "type": "array",
                  "items": {
                    "type": "string"
                  },
                  "maxItems": 5
                }
              }
            },
            "type": "http",
            "method": "POST",
            "bodyType": "json"
          },
          "output": {
            "type": "json",
            "example": {
              "summary": "The claim conflates two products…",
              "verdict": "refuted",
              "citations": [
                "https://example.com/changelog"
              ],
              "confidence": 0.93
            }
          }
        },
        "schema": {
          "type": "object",
          "$schema": "https://json-schema.org/draft/2020-12/schema",
          "required": [
            "input"
          ],
          "properties": {
            "input": {
              "type": "object",
              "required": [
                "type",
                "bodyType",
                "body",
                "method"
              ],
              "properties": {
                "body": {
                  "properties": {}
                },
                "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"
                }
              }
            }
          }
        }
      }
    },
    "x402Version": 2
  },
  {
    "error": "Payment required",
    "accepts": [
      {
        "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "payTo": "0xa12d480B17797f2401949130bEcBeC24c754ed30",
        "amount": "200000",
        "scheme": "exact",
        "network": "eip155:8453",
        "maxTimeoutSeconds": 60
      },
      {
        "asset": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "payTo": "0xa12d480B17797f2401949130bEcBeC24c754ed30",
        "amount": "200000",
        "scheme": "exact",
        "network": "eip155:137",
        "maxTimeoutSeconds": 60
      },
      {
        "asset": "31566704",
        "extra": {
          "name": "USDC",
          "decimals": 6,
          "feePayer": "ZMFK2OI7ZBD2U27ISERZC4S6LKM6WMFJPZQ4MYNJDZ2VNBNMBA67RA22AA"
        },
        "payTo": "X4BGQO53SBYIPXGE22E3C4BXJZKYKUYG3PZQVDBNUIVB64D6K7MEVGGCSM",
        "amount": "200000",
        "scheme": "exact",
        "network": "algorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73ktiC1qzkkit8=",
        "maxTimeoutSeconds": 60
      },
      {
        "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
        "extra": {
          "feePayer": "8a8fFNfk2AGS7rgVv1BoqPUWnzQuoCrShJV8tSE6RAYi"
        },
        "payTo": "8ZBEGCRdwQ5hAq1seaUbmQ7D8JRJnq4fETFK1k22Dpmy",
        "amount": "200000",
        "scheme": "exact",
        "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
        "maxTimeoutSeconds": 60
      }
    ],
    "resource": {
      "url": "https://secondopinionx402.com/v1/verify/async",
      "mimeType": "application/json",
      "description": "Second Opinion (async): pay, receive a job id in seconds, poll the free result URL for the verdict. Same product as /v1/verify; required for Solana payments, kinder for all rails."
    },
    "extensions": {
      "bazaar": {
        "info": {
          "input": {
            "body": {
              "type": "object",
              "required": [
                "claim"
              ],
              "properties": {
                "claim": {
                  "type": "string",
                  "maxLength": 2000,
                  "minLength": 8
                },
                "context": {
                  "type": "string",
                  "maxLength": 4000
                },
                "claimed_sources": {
                  "type": "array",
                  "items": {
                    "type": "string"
                  },
                  "maxItems": 5
                }
              }
            },
            "type": "http",
            "method": "POST",
            "bodyType": "json"
          },
          "output": {
            "type": "json",
            "example": {
              "job_id": "job_…",
              "status": "queued",
              "result_url": "https://…/v1/jobs/job_…",
              "estimated_seconds": 60
            }
          }
        },
        "schema": {
          "type": "object",
          "$schema": "https://json-schema.org/draft/2020-12/schema",
          "required": [
            "input"
          ],
          "properties": {
            "input": {
              "type": "object",
              "required": [
                "type",
                "bodyType",
                "body",
                "method"
              ],
              "properties": {
                "body": {
                  "properties": {}
                },
                "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"
                }
              }
            }
          }
        }
      }
    },
    "x402Version": 2
  },
  {
    "error": "Payment required",
    "accepts": [
      {
        "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "payTo": "0xa12d480B17797f2401949130bEcBeC24c754ed30",
        "amount": "750000",
        "scheme": "exact",
        "network": "eip155:8453",
        "maxTimeoutSeconds": 60
      },
      {
        "asset": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "payTo": "0xa12d480B17797f2401949130bEcBeC24c754ed30",
        "amount": "750000",
        "scheme": "exact",
        "network": "eip155:137",
        "maxTimeoutSeconds": 60
      },
      {
        "asset": "31566704",
        "extra": {
          "name": "USDC",
          "decimals": 6,
          "feePayer": "ZMFK2OI7ZBD2U27ISERZC4S6LKM6WMFJPZQ4MYNJDZ2VNBNMBA67RA22AA"
        },
        "payTo": "X4BGQO53SBYIPXGE22E3C4BXJZKYKUYG3PZQVDBNUIVB64D6K7MEVGGCSM",
        "amount": "750000",
        "scheme": "exact",
        "network": "algorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73ktiC1qzkkit8=",
        "maxTimeoutSeconds": 60
      },
      {
        "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
        "extra": {
          "feePayer": "8a8fFNfk2AGS7rgVv1BoqPUWnzQuoCrShJV8tSE6RAYi"
        },
        "payTo": "8ZBEGCRdwQ5hAq1seaUbmQ7D8JRJnq4fETFK1k22Dpmy",
        "amount": "750000",
        "scheme": "exact",
        "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
        "maxTimeoutSeconds": 60
      }
    ],
    "resource": {
      "url": "https://secondopinionx402.com/v1/verify/panel/async",
      "mimeType": "application/json",
      "description": "Second Opinion panel (async): three-skeptic panel as a polled job. Same product as /v1/verify/panel; required for Solana payments."
    },
    "extensions": {
      "bazaar": {
        "info": {
          "input": {
            "body": {
              "type": "object",
              "required": [
                "claim"
              ],
              "properties": {
                "claim": {
                  "type": "string",
                  "maxLength": 2000,
                  "minLength": 8
                },
                "context": {
                  "type": "string",
                  "maxLength": 4000
                },
                "claimed_sources": {
                  "type": "array",
                  "items": {
                    "type": "string"
                  },
                  "maxItems": 5
                }
              }
            },
            "type": "http",
            "method": "POST",
            "bodyType": "json"
          },
          "output": {
            "type": "json",
            "example": {
              "job_id": "job_…",
              "status": "queued",
              "result_url": "https://…/v1/jobs/job_…",
              "estimated_seconds": 90
            }
          }
        },
        "schema": {
          "type": "object",
          "$schema": "https://json-schema.org/draft/2020-12/schema",
          "required": [
            "input"
          ],
          "properties": {
            "input": {
              "type": "object",
              "required": [
                "type",
                "bodyType",
                "body",
                "method"
              ],
              "properties": {
                "body": {
                  "properties": {}
                },
                "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"
                }
              }
            }
          }
        }
      }
    },
    "x402Version": 2
  },
  {
    "error": "Payment required",
    "accepts": [
      {
        "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "payTo": "0xa12d480B17797f2401949130bEcBeC24c754ed30",
        "amount": "20000",
        "scheme": "exact",
        "network": "eip155:8453",
        "maxTimeoutSeconds": 60
      },
      {
        "asset": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "payTo": "0xa12d480B17797f2401949130bEcBeC24c754ed30",
        "amount": "20000",
        "scheme": "exact",
        "network": "eip155:137",
        "maxTimeoutSeconds": 60
      },
      {
        "asset": "31566704",
        "extra": {
          "name": "USDC",
          "decimals": 6,
          "feePayer": "ZMFK2OI7ZBD2U27ISERZC4S6LKM6WMFJPZQ4MYNJDZ2VNBNMBA67RA22AA"
        },
        "payTo": "X4BGQO53SBYIPXGE22E3C4BXJZKYKUYG3PZQVDBNUIVB64D6K7MEVGGCSM",
        "amount": "20000",
        "scheme": "exact",
        "network": "algorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73ktiC1qzkkit8=",
        "maxTimeoutSeconds": 60
      }
    ],
    "resource": {
      "url": "https://secondopinionx402.com/v1/verify/quick",
      "mimeType": "application/json",
      "description": "Second Opinion quick: an independent reasoning-only check (no web research) of your claim's logic and consistency with established knowledge. Honest 'inconclusive' when the claim needs live research."
    },
    "extensions": {
      "bazaar": {
        "info": {
          "input": {
            "body": {
              "type": "object",
              "required": [
                "claim"
              ],
              "properties": {
                "claim": {
                  "type": "string",
                  "maxLength": 2000,
                  "minLength": 8
                },
                "context": {
                  "type": "string",
                  "maxLength": 4000
                },
                "claimed_sources": {
                  "type": "array",
                  "items": {
                    "type": "string"
                  },
                  "maxItems": 5
                }
              }
            },
            "type": "http",
            "method": "POST",
            "bodyType": "json"
          },
          "output": {
            "type": "json",
            "example": {
              "summary": "The conclusion does not follow…",
              "verdict": "refuted",
              "confidence": 0.9,
              "searched_web": false
            }
          }
        },
        "schema": {
          "type": "object",
          "$schema": "https://json-schema.org/draft/2020-12/schema",
          "required": [
            "input"
          ],
          "properties": {
            "input": {
              "type": "object",
              "required": [
                "type",
                "bodyType",
                "body",
                "method"
              ],
              "properties": {
                "body": {
                  "properties": {}
                },
                "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"
                }
              }
            }
          }
        }
      }
    },
    "x402Version": 2
  },
  {
    "error": "Payment required",
    "accepts": [
      {
        "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "payTo": "0xa12d480B17797f2401949130bEcBeC24c754ed30",
        "amount": "750000",
        "scheme": "exact",
        "network": "eip155:8453",
        "maxTimeoutSeconds": 300
      },
      {
        "asset": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "payTo": "0xa12d480B17797f2401949130bEcBeC24c754ed30",
        "amount": "750000",
        "scheme": "exact",
        "network": "eip155:137",
        "maxTimeoutSeconds": 300
      },
      {
        "asset": "31566704",
        "extra": {
          "name": "USDC",
          "decimals": 6,
          "feePayer": "ZMFK2OI7ZBD2U27ISERZC4S6LKM6WMFJPZQ4MYNJDZ2VNBNMBA67RA22AA"
        },
        "payTo": "X4BGQO53SBYIPXGE22E3C4BXJZKYKUYG3PZQVDBNUIVB64D6K7MEVGGCSM",
        "amount": "750000",
        "scheme": "exact",
        "network": "algorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73ktiC1qzkkit8=",
        "maxTimeoutSeconds": 300
      }
    ],
    "resource": {
      "url": "https://secondopinionx402.com/v1/verify/panel",
      "mimeType": "application/json",
      "description": "Second Opinion panel: three independent skeptics attack the claim via different lenses (evidence, logic, currency). Majority verdict with per-seat breakdown."
    },
    "extensions": {
      "bazaar": {
        "info": {
          "input": {
            "body": {
              "type": "object",
              "required": [
                "claim"
              ],
              "properties": {
                "claim": {
                  "type": "string",
                  "maxLength": 2000,
                  "minLength": 8
                },
                "context": {
                  "type": "string",
                  "maxLength": 4000
                },
                "claimed_sources": {
                  "type": "array",
                  "items": {
                    "type": "string"
                  },
                  "maxItems": 5
                }
              }
            },
            "type": "http",
            "method": "POST",
            "bodyType": "json"
          },
          "output": {
            "type": "json",
            "example": {
              "panel": [
                {
                  "lens": "evidence",
                  "verdict": "supported",
                  "confidence": 0.85
                }
              ],
              "verdict": "supported",
              "confidence": 0.81
            }
          }
        },
        "schema": {
          "type": "object",
          "$schema": "https://json-schema.org/draft/2020-12/schema",
          "required": [
            "input"
          ],
          "properties": {
            "input": {
              "type": "object",
              "required": [
                "type",
                "bodyType",
                "body",
                "method"
              ],
              "properties": {
                "body": {
                  "properties": {}
                },
                "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"
                }
              }
            }
          }
        }
      }
    },
    "x402Version": 2
  },
  {
    "error": "Payment required",
    "accepts": [
      {
        "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "payTo": "0xa12d480B17797f2401949130bEcBeC24c754ed30",
        "amount": "20000",
        "scheme": "exact",
        "network": "eip155:8453",
        "maxTimeoutSeconds": 60
      },
      {
        "asset": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "payTo": "0xa12d480B17797f2401949130bEcBeC24c754ed30",
        "amount": "20000",
        "scheme": "exact",
        "network": "eip155:137",
        "maxTimeoutSeconds": 60
      },
      {
        "asset": "31566704",
        "extra": {
          "name": "USDC",
          "decimals": 6,
          "feePayer": "ZMFK2OI7ZBD2U27ISERZC4S6LKM6WMFJPZQ4MYNJDZ2VNBNMBA67RA22AA"
        },
        "payTo": "X4BGQO53SBYIPXGE22E3C4BXJZKYKUYG3PZQVDBNUIVB64D6K7MEVGGCSM",
        "amount": "20000",
        "scheme": "exact",
        "network": "algorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73ktiC1qzkkit8=",
        "maxTimeoutSeconds": 60
      },
      {
        "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
        "extra": {
          "feePayer": "8a8fFNfk2AGS7rgVv1BoqPUWnzQuoCrShJV8tSE6RAYi"
        },
        "payTo": "8ZBEGCRdwQ5hAq1seaUbmQ7D8JRJnq4fETFK1k22Dpmy",
        "amount": "20000",
        "scheme": "exact",
        "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
        "maxTimeoutSeconds": 60
      }
    ],
    "resource": {
      "url": "https://secondopinionx402.com/v1/verify/quick/async",
      "mimeType": "application/json",
      "description": "Second Opinion quick (async): reasoning-only check as a polled job. Required for Solana payments."
    },
    "extensions": {
      "bazaar": {
        "info": {
          "input": {
            "body": {
              "type": "object",
              "required": [
                "claim"
              ],
              "properties": {
                "claim": {
                  "type": "string",
                  "maxLength": 2000,
                  "minLength": 8
                },
                "context": {
                  "type": "string",
                  "maxLength": 4000
                },
                "claimed_sources": {
                  "type": "array",
                  "items": {
                    "type": "string"
                  },
                  "maxItems": 5
                }
              }
            },
            "type": "http",
            "method": "POST",
            "bodyType": "json"
          },
          "output": {
            "type": "json",
            "example": {
              "job_id": "job_…",
              "status": "queued",
              "result_url": "https://…/v1/jobs/job_…",
              "estimated_seconds": 15
            }
          }
        },
        "schema": {
          "type": "object",
          "$schema": "https://json-schema.org/draft/2020-12/schema",
          "required": [
            "input"
          ],
          "properties": {
            "input": {
              "type": "object",
              "required": [
                "type",
                "bodyType",
                "body",
                "method"
              ],
              "properties": {
                "body": {
                  "properties": {}
                },
                "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"
                }
              }
            }
          }
        }
      }
    },
    "x402Version": 2
  }
]

OVER TIME

All charts use the 90d selector; each series spans only the dates it has data for. Every series is also served as JSON at /api/v1/services/second-opinion-ms0hen6l-0/price, /scores, /volume and /buyers. On-chain volume and distinct buyers are measured over the service's settlement address and are a conservative undercount (only settlements that reach a measured facilitator are counted). The on-chain series roll up hourly, so the latest day can be up to about an hour behind; distinct buyers are counted per payout address, so a service that settles to more than one address is an upper bound.

UPTIME

90d UPTIME 100%

RESPONSE TIME

AVG RESP 577ms

PRICE (captured 402, USD)

Median across 6 endpoints. Use the selector to isolate one.

SUB-SCORES (uptime + x402 compliance)

checklist grew 11->14 on 2026-07-28; a step here is a metric change, not a regression

PILLARS OVER TIME (measured)

price percentile in Verification

site signals present (of 6)

Measured site and economics pillars from the assessment history, so the latest value shown elsewhere on this page reads as a point on a trend rather than a permanent state.

VOLUME (on-chain settlement, USD)

This service settles on a network x402-list does not measure yet, so on-chain volume is not counted here. Shown as unmeasured, not zero.

DISTINCT BUYERS

This service settles on a network x402-list does not measure yet, so distinct on-chain buyers are not counted here. Shown as unmeasured, not zero.

COMPLIANCE

14/14 checks pass · grade A

last 402 captured 2026-08-10 · last up 2026-09-08

402 payload captured
accepts[] array present
payTo address recoverable
payTo at accepts[0].payTo (conformant shape)
payTo is a valid on-chain address
atomic price declared
atomic price in a sane range
asset (token) address declared
network resolves to CAIP-2
payment scheme declared
served over HTTPS
declares the current x402 version (2)
EIP-712 domain parameters present on every EVM entry
x402 v2 envelope delivered in the payment-required header

SITE PILLARS

homepage reachable
openapi doc
pricing page
llms.txt
robots.txt
terms page

recent checks (18) live · click to expand

TIME STATUS RESP CAUSE

23:03:25 UTC ● OK 582ms

22:47:27 UTC ● OK 219ms

22:31:28 UTC ● OK 118ms

22:15:24 UTC ● SLOW 1009ms

21:59:27 UTC ● SLOW 1308ms

21:43:23 UTC ● SLOW 906ms

21:27:23 UTC ● OK 289ms

21:11:19 UTC ● OK 172ms

20:55:26 UTC ● OK 797ms

20:39:19 UTC ● OK 454ms

20:23:21 UTC ● OK 508ms

20:07:21 UTC ● OK 546ms

19:51:23 UTC ● OK 347ms

19:35:20 UTC ● OK 689ms

19:19:23 UTC ● OK 262ms

19:03:25 UTC ● SLOW 920ms

18:47:22 UTC ● OK 326ms

18:31:26 UTC ● SLOW 1211ms

EMBED THIS BADGE

Show that Second Opinion is monitored on x402-list. Paste this on your site or README, it links back to this live listing.

status

Second Opinion uptime on x402-list — live uptime

// HTML

<a href="https://x402-list.com/services/second-opinion-ms0hen6l-0?utm_source=badge&utm_medium=referral&utm_campaign=embed">
  <img src="https://x402-list.com/badge/second-opinion-ms0hen6l-0.svg" alt="Second Opinion listed on x402-list" height="28">
</a>

// Markdown

[![Second Opinion on x402-list](https://x402-list.com/badge/second-opinion-ms0hen6l-0.svg)](https://x402-list.com/services/second-opinion-ms0hen6l-0?utm_source=badge&utm_medium=referral&utm_campaign=embed)

// HTML · live uptime variant

<a href="https://x402-list.com/services/second-opinion-ms0hen6l-0?utm_source=badge&utm_medium=referral&utm_campaign=embed">
  <img src="https://x402-list.com/badge/second-opinion-ms0hen6l-0.svg?data=uptime" alt="Second Opinion uptime on x402-list" height="28">
</a>

RUN THIS SERVICE?

Keep this listing accurate: propose changes to the name, description, website, category or add new endpoints to monitor. Ownership is verified with a domain proof and every change is reviewed manually; measured data stays read-only.

[ update this listing ]

Earn the verified tier: x402list pays a real call to this endpoint and, if it delivers, the service is delivery-verified. The fee covers the cost of the probe, not the badge; there is no refund if the call does not deliver. Agent and API only, no in-browser signing. See /api.

[ verify this service ($0.25) ]

To request delisting, email info@x402-list.com or update your listing at /services/second-opinion-ms0hen6l-0/update.