Second Opinion
VerificationAdversarial 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 verdict ($0.75). USDC via x402 on Algorand, Base, and Solana. No accounts, no API keys.
Pay from $0.03 to $0.75 per request in USDC on Base / Solana, settled onchain via the x402 protocol, no signup, no API key needed.
listed 2026-07-25 · no on-chain settlement recorded yet
ASSESSMENT
updated 3h agoEvidence-backed signals, not a single score. Click any chip for the proof. Measured values stay read-only; unknown is honest.
reliability 100%
- uptime 24h
- -
- uptime 7d
- -
- uptime 30d
- -
- uptime 90d
- -
- response p95
- 289ms
- avg response
- 289ms
- total checks
- 1
compliance B (9/11): payTo is a valid on-chain address, network resolves to CAIP-2
9 of 11 x402 conformance checks pass; failing: payTo is a valid on-chain address, network resolves to CAIP-2. Full checklist below.
price $0.03 to $0.75 (p80 in Verification)
- price (min)
- $0.03
- price (max)
- $0.75
- category percentile (min)
- p80 in Verification
- category percentile (max)
- p82 in Verification
- endpoints / prices
- 6 / 3
- model
- tiered
- stability
- 100%
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
- 3d
- registrar
- GoDaddy.com, LLC
- hosting
- custom
- domain created
- 2026-07-22
Identity facts, not a risk score.
traction $0 30d · 0 buyers
- volume 30d
- $0
- buyers 30d
- 0
- settlements 30d
- 0
- first settlement
- ---
- last settlement
- ---
- top buyer share
- -
- trend 7d vs 30d
- -
- networks
- eip155:8453, solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdpKuc147dw2N9d
- volume all-time
- $0
- settlements all-time
- 0
- median settlement 30d
- $0
- max settlement 30d
- $0
- settled via
- -
Conservative undercount: only USDC settlements via facilitators we measure are counted. A measured floor, not an estimate.
Top buyer share is a concentration signal, not part of the ranking score.
WHAT IT DOES
ai-derivedProvides adversarial verification services for AI agents with different verification levels and pricing options.
- category
- ai-verification
- in
- body
- auth
- none
AI-generated summary. The measured data is never altered by it.
ENDPOINTS
| METHOD | PATH | DESCRIPTION | PRICE | NETWORK | ASSET |
|---|---|---|---|---|---|
| POST | /v1/verify | $0.20 | Base | USDC | |
| POST | /v1/verify/async | $0.20 | Base/Solana | USDC | |
| POST | /v1/verify/panel | $0.75 | Base | USDC | |
| POST | /v1/verify/panel/async | $0.75 | Base/Solana | USDC | |
| POST | /v1/verify/quick | $0.03 | Base | USDC | |
| POST | /v1/verify/quick/async | $0.03 | Base/Solana | USDC |
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.
curl -i -X POST 'https://secondopinionx402.com/v1/verify'
// 402 response (captured by monitor) · 6 payloads · click to expand
[
{
"error": "Payment required",
"accepts": [
{
"asset": "31566704",
"extra": {
"name": "USDC",
"decimals": 6,
"feePayer": "ZMFK2OI7ZBD2U27ISERZC4S6LKM6WMFJPZQ4MYNJDZ2VNBNMBA67RA22AA"
},
"payTo": "X4BGQO53SBYIPXGE22E3C4BXJZKYKUYG3PZQVDBNUIVB64D6K7MEVGGCSM",
"amount": "30000",
"scheme": "exact",
"network": "algorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73ktiC1qzkkit8=",
"maxTimeoutSeconds": 60
},
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"version": "2"
},
"payTo": "0xa12d480B17797f2401949130bEcBeC24c754ed30",
"amount": "30000",
"scheme": "exact",
"network": "eip155:8453",
"maxTimeoutSeconds": 60
},
{
"asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
"extra": {
"feePayer": "8a8fFNfk2AGS7rgVv1BoqPUWnzQuoCrShJV8tSE6RAYi"
},
"payTo": "8ZBEGCRdwQ5hAq1seaUbmQ7D8JRJnq4fETFK1k22Dpmy",
"amount": "30000",
"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
},
{
"error": "Payment required",
"accepts": [
{
"asset": "31566704",
"extra": {
"name": "USDC",
"decimals": 6,
"feePayer": "ZMFK2OI7ZBD2U27ISERZC4S6LKM6WMFJPZQ4MYNJDZ2VNBNMBA67RA22AA"
},
"payTo": "X4BGQO53SBYIPXGE22E3C4BXJZKYKUYG3PZQVDBNUIVB64D6K7MEVGGCSM",
"amount": "200000",
"scheme": "exact",
"network": "algorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73ktiC1qzkkit8=",
"maxTimeoutSeconds": 60
},
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"version": "2"
},
"payTo": "0xa12d480B17797f2401949130bEcBeC24c754ed30",
"amount": "200000",
"scheme": "exact",
"network": "eip155:8453",
"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": "31566704",
"extra": {
"name": "USDC",
"decimals": 6,
"feePayer": "ZMFK2OI7ZBD2U27ISERZC4S6LKM6WMFJPZQ4MYNJDZ2VNBNMBA67RA22AA"
},
"payTo": "X4BGQO53SBYIPXGE22E3C4BXJZKYKUYG3PZQVDBNUIVB64D6K7MEVGGCSM",
"amount": "750000",
"scheme": "exact",
"network": "algorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73ktiC1qzkkit8=",
"maxTimeoutSeconds": 60
},
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"version": "2"
},
"payTo": "0xa12d480B17797f2401949130bEcBeC24c754ed30",
"amount": "750000",
"scheme": "exact",
"network": "eip155:8453",
"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": "31566704",
"extra": {
"name": "USDC",
"decimals": 6,
"feePayer": "ZMFK2OI7ZBD2U27ISERZC4S6LKM6WMFJPZQ4MYNJDZ2VNBNMBA67RA22AA"
},
"payTo": "X4BGQO53SBYIPXGE22E3C4BXJZKYKUYG3PZQVDBNUIVB64D6K7MEVGGCSM",
"amount": "30000",
"scheme": "exact",
"network": "algorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73ktiC1qzkkit8=",
"maxTimeoutSeconds": 60
},
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"version": "2"
},
"payTo": "0xa12d480B17797f2401949130bEcBeC24c754ed30",
"amount": "30000",
"scheme": "exact",
"network": "eip155:8453",
"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": "31566704",
"extra": {
"name": "USDC",
"decimals": 6,
"feePayer": "ZMFK2OI7ZBD2U27ISERZC4S6LKM6WMFJPZQ4MYNJDZ2VNBNMBA67RA22AA"
},
"payTo": "X4BGQO53SBYIPXGE22E3C4BXJZKYKUYG3PZQVDBNUIVB64D6K7MEVGGCSM",
"amount": "200000",
"scheme": "exact",
"network": "algorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73ktiC1qzkkit8=",
"maxTimeoutSeconds": 120
},
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"version": "2"
},
"payTo": "0xa12d480B17797f2401949130bEcBeC24c754ed30",
"amount": "200000",
"scheme": "exact",
"network": "eip155:8453",
"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": "31566704",
"extra": {
"name": "USDC",
"decimals": 6,
"feePayer": "ZMFK2OI7ZBD2U27ISERZC4S6LKM6WMFJPZQ4MYNJDZ2VNBNMBA67RA22AA"
},
"payTo": "X4BGQO53SBYIPXGE22E3C4BXJZKYKUYG3PZQVDBNUIVB64D6K7MEVGGCSM",
"amount": "750000",
"scheme": "exact",
"network": "algorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73ktiC1qzkkit8=",
"maxTimeoutSeconds": 300
},
{
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"extra": {
"name": "USD Coin",
"version": "2"
},
"payTo": "0xa12d480B17797f2401949130bEcBeC24c754ed30",
"amount": "750000",
"scheme": "exact",
"network": "eip155:8453",
"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
}
] OVER TIME
All charts share the 30d window selected here. 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.
Median across 6 endpoints. Use the selector to isolate one.
COMPLIANCE
9/11 checks pass · grade B · failing: payTo is a valid on-chain address, network resolves to CAIP-2- 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
SITE PILLARS
- homepage reachable
- openapi doc
- pricing page
- llms.txt
- robots.txt
- terms page
recent checks (13) · click to expand
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