Second Opinion MCP Server

by secondopinionx402 Your server? Claim it

answering

Second Opinion is answering right now. Last checked 9 min ago. It exposes 6 tools.

Adversarial verification for AI agents - pay an independent skeptic per verdict in USDC via x402.

Uptime history 47 days of history · worst day 99%

47 days agonow

100.0%

Uptime 24h

91 of 91 checks

Tools

read from the server

330 ms

Response time

average over 24h

open, no key

Access

streamable-http

What changed 2

Every tool that appeared, vanished or quietly changed what it asks for. Recorded since 10 August 2026. No other catalogue keeps this.

13 Aug a tool changed version

10 Aug a tool description was rewritten second_opinion_pricing

Nothing serious here today

Today is the operative word: we check Second Opinion every 15 minutes and re-read its code on every release. Watch it and you find out the day that stops being true.

Connect this server

Endpoint below is the one we actually reach during checks — not the one copied from a README. Last verified 9 min ago.

Claude Code Claude Desktop Codex Cursor VS Code

run in your terminal

claude mcp add second-opinion --transport http https://secondopinionx402.com/mcp

~/Library/Application Support/Claude/claude_desktop_config.json

{
  "mcpServers": {
    "second-opinion": {
      "url": "https://secondopinionx402.com/mcp"
    }
  }
}

~/.codex/config.toml

[mcp_servers.second-opinion]
url = "https://secondopinionx402.com/mcp"

.cursor/mcp.json

{
  "mcpServers": {
    "second-opinion": {
      "url": "https://secondopinionx402.com/mcp"
    }
  }
}

.vscode/mcp.json

{
  "mcpServers": {
    "second-opinion": {
      "url": "https://secondopinionx402.com/mcp"
    }
  }
}

Available tools 6

Read directly from the server with tools/list, grouped by what they act on. If a tool disappears, we record the date.

second

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 returns an exact pay-per-call quote (no account, no API key).

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 calibrated confidence; honestly escalates to second_opinion_verify when the claim needs current-world research. Without a payment argument it returns an exact pay-per-call quote (no account, no API key).

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.

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-verifiable Ed25519 receipt and live web research on the verify/panel tiers. Try the product here; use the paid tools for real work.

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-world facts. Without a payment argument it returns an exact pay-per-call quote (no account, no API key).

Endpoints

URL	Transport	State	Latency	Checked
https://secondopinionx402.com/mcp	streamable-http	answering	317 ms	9 min ago

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Second Opinion — questions

Answers built from our own checks of this server.

What can Second Opinion do?

It exposes 6 tools, read directly from the server on our last check. Among them: second_opinion_panel, second_opinion_pricing, second_opinion_quick, second_opinion_result, second_opinion_try, second_opinion_verify. The full list with descriptions is on this page — we take it from the server itself via tools/list, not from a README. How MCP servers expose tools in the first place →

Is Second Opinion working right now?

We send a real MCP handshake every 15 minutes. Over the last 24 hours 91 of 91 checks got a reply (100.0%), average response time 330 ms. The bar chart above shows every period we have measured.

How do I connect Second Opinion?

Copy the ready config from this page — we generate it for Claude Code, Claude Desktop, Codex, Cursor and VS Code, each with the file path that client actually reads. It is a remote server, so there is nothing to install — the client connects to the address.

Does Second Opinion need an API key?

No. Second Opinion completed a full MCP handshake with us as an anonymous client and listed its tools without asking for anything. All 6 of them are readable on this page. This is what we observed, not what the docs claim.

How fast is Second Opinion?

It answers our handshake in 330 ms on average, which is faster than 46% of all working MCP servers we measure. The comparison comes from our own checks across the whole registry, every 15 minutes.