Second Opinion is an MCP server with 6 tools an agent can call, among them second_opinion_panel, second_opinion_pricing, second_opinion_quick. It answers at https://secondopinionx402.com/mcp over streamable HTTP, and it listed its tools to an anonymous client, so no sign-in was needed for that. Our probes reached it 6 of 6 times since 10 September 2026; the last check, on 19 October 2026, succeeded.
Adversarial verification for AI agents - pay an independent skeptic per verdict in USDC via x402.
Description as the publisher wrote it.
| Tool | What it does |
|---|---|
second_opinion_panel | Three independent adversarial verifiers attack the claim through different lenses (evidence, logic, currency) and vote ($0.75, ~90s). Use for high-stakes or contested claims where a single check is not enough. Without a payment argument it Inputs: claim, context, payment |
second_opinion_pricing | FREE: current tiers, prices, and exact on-chain payment requirements (accepts) for every rail — Algorand, Base, Polygon, Solana. Use this to pre-build a payment, or to discover what a verification will cost before committing. |
second_opinion_quick | Independent reasoning-only check of a claim ($0.02, ~20s, no web research). Use for logic, internal consistency, and stable established knowledge (definitions, architectures, history, maths). Returns refuted/supported/inconclusive with cali Inputs: claim, context, payment |
second_opinion_result | Fetch the verdict for a paid async job — polling is FREE and the verdict is already paid for. Returns status running|done|failed, with the full verdict when done. Inputs: job_id |
second_opinion_try | FREE TRIAL — no wallet, no payment, no account: the same quick reasoning-only check as second_opinion_quick, 3/day per caller (claims up to 500 chars; global daily cap applies). The trial verdict is unsigned — paid verdicts add an offline-v Inputs: claim, context |
second_opinion_verify | Independent adversarial verification with live web research ($0.20, ~60s). A separate AI attempts to refute the claim using current sources and returns a verdict with citations. Use before irreversible commitments that depend on current-wor Inputs: claim, context, payment, claimed_sources |
Every block below points at https://secondopinionx402.com/mcp. Pick your client and copy.
claude mcp add --transport http second-opinion https://secondopinionx402.com/mcp
{
"mcpServers": {
"second-opinion": {
"command": "npx",
"args": ["-y", "mcp-remote", "https://secondopinionx402.com/mcp"]
}
}
}{
"mcpServers": {
"second-opinion": {
"url": "https://secondopinionx402.com/mcp"
}
}
}{
"servers": {
"second-opinion": {
"type": "http",
"url": "https://secondopinionx402.com/mcp"
}
}
}{
"context_servers": {
"second-opinion": {
"url": "https://secondopinionx402.com/mcp"
}
}
}{
"mcpServers": {
"second-opinion": {
"serverUrl": "https://secondopinionx402.com/mcp"
}
}
}{
"mcpServers": {
"second-opinion": {
"url": "https://secondopinionx402.com/mcp"
}
}
}name: Second Opinion
version: 0.0.1
schema: v1
mcpServers:
- name: Second Opinion
type: streamable-http
url: https://secondopinionx402.com/mcp{
"mcpServers": {
"second-opinion": {
"httpUrl": "https://secondopinionx402.com/mcp"
}
}
}{
"mcpServers": {
"second-opinion": {
"type": "http",
"url": "https://secondopinionx402.com/mcp"
}
}
}{
"mcpServers": {
"second-opinion": {
"url": "https://secondopinionx402.com/mcp"
}
}
}goose://extension?url=https%3A%2F%2Fsecondopinionx402.com%2Fmcp&type=streamable_http&id=second-opinion&name=Second%20Opinion
It answered our last check on 19 October 2026 in 333 ms. Over 6 checks since 10 September 2026 it answered 6. Status here comes from Neuronto's own probes, not from the publisher.
Yes. It is published by secondopinionx402.com and served from secondopinionx402.com, the vendor's own domain: https://secondopinionx402.com/mcp.
6, as returned by the server's own tools/list on 11 September 2026: second_opinion_panel, second_opinion_pricing, second_opinion_quick, second_opinion_result, second_opinion_try, second_opinion_verify.
It answered our last check on 19 October 2026 in 333 ms. Over 6 checks since 10 September 2026 it answered 6.
Put the server under mcpServers in ~/.cursor/mcp.json with the URL https://secondopinionx402.com/mcp. The exact JSON is above, with the same setup for Claude Code, Claude Desktop, VS Code, Windsurf, Zed, Gemini CLI and the rest.
It listed its tools to an anonymous client, so reading the tool list needs no key. Individual tools can still ask for credentials in their own inputs.
Publisher: com.secondopinionx402. Endpoint host: secondopinionx402.com. ARD identifier: urn:air:com.secondopinionx402:mcp:second-opinion.
First indexed 10 September 2026. The tools are exactly what the server returned; nothing on this page
is inferred from its name. Ranking in Neuronto search is never for sale.