How do I install Verity?

Copy the stdio config for Cursor, Claude Desktop, Claude Code, or VS Code on this page. It uses the publisher's install, not a PlugMCP proxy.

Does Verity need an API key?

The publisher lists these environment variables: VERITY_PRIVATE_KEY.

What transport does Verity use?

Verity runs locally over stdio.

When was Verity last checked?

Last checked 2026-11-09. Real-time fact-checking MCP. Verifies claims against live sources with structured verdicts.

Verity MCP server

1{2 "mcpServers": {3 "io.github.clawdio777-verity": {4 "command": "npx",5 "args": [6 "-y",7 "[email protected]"8 ],9 "env": {10 "VERITY_PRIVATE_KEY": "<secret>"11 }12 }13 }14}

VERITY — Real-Time Fact-Checking Agent

Real-time fact-checking and data freshness agent. Verifies claims, URLs, and content against live web sources. Returns structured verdicts with confidence scores, what has changed, and supporting sources.

Verdicts

Verdict	Meaning
`CURRENT`	Claim is accurate and up to date
`OUTDATED`	Claim was true but has since been superseded
`DISPUTED`	Sources disagree — no clear consensus
`UNVERIFIABLE`	No usable sources found

MCP Setup (Claude Desktop / Cursor)

{
  "mcpServers": {
    "verity": {
      "command": "npx",
      "args": ["verity-mcp"],
      "env": {
        "VERITY_PRIVATE_KEY": "0x..."
      }
    }
  }
}

Get USDC on Base at coinbase.com/wallet.

Tools

Tool	Description	Price
`verity_verify`	Verify a claim or URL against live sources	0.10 USDC
`verity_deep_check`	Multi-angle thorough verification	0.50 USDC
`verity_batch`	Verify up to 10 claims at once	0.75 USDC
`verity_agent`	Natural language fact-checking	0.10 USDC
`check_credits`	Remaining balance for a PayGated `pg_` key	free

API

POST https://verity.basechainlabs.com/api/verify
Authorization: x402 (USDC on Base)

{
  "claim": "Is GPT-4 still the most capable OpenAI model?",
  "caller_id": "my-agent-id"
}

Response:

{
  "verdict": "OUTDATED",
  "confidence": 91,
  "summary": "GPT-4 has been superseded by GPT-4o and o3.",
  "what_changed": "OpenAI released GPT-4o (May 2024) and o3 (late 2024).",
  "sources": [{ "url": "...", "title": "...", "published_date": "2025-01", "supports": "CONTRADICTS" }],
  "checked_at": "2026-05-11T09:00:00Z",
  "recommendation": "Update any content referencing GPT-4 as the most capable model."
}

Persistent Memory

Pass a consistent caller_id on every call. VERITY remembers topics you've checked, domains you monitor, and previous results — no re-sending context.

A2A Agent Card

GET https://verity.basechainlabs.com/api/agent?agent-card=true

Built by BaseChain Labs

Making changes (maintainer guide)

Where things live

Thing	Where
The agent's brain	`src/agent.ts` (system prompt, orchestration), `src/tools.ts` (fact-checking: Tavily search + Claude verdicts)
API endpoints	one file per route under `api/`: `agent` (paid A2A entry), `verify`, `deep-check`, `batch-verify`, `mcp`, `checkout`, `stripe-webhook`, `recover-key`, plus the `cron-check-deps` and `daily-summary` crons
Payment gate	`api/_x402-gate.ts`: unpaid POSTs get HTTP 402 with the price and the Bazaar listing; GET returns the agent card
Public page	`public/index.html` (plain HTML). Agent card: `public/.well-known/agent.json`
Marketplace seller	`seller-v2.mjs` + `Dockerfile` + `railway.json`, the Virtuals ACP seller on Railway. Its keyring lives on a Railway volume; `keyring.json` and `keyring.key` are runtime files and gitignored
Secrets	hosting environment variables only. Never in a file, never in a commit

How a change goes live

There is no test suite and no CI on this repo. A push to main is the deploy.

Edit, then type-check: npx tsc --noEmit -p .
Commit and push to main. Vercel builds and deploys production from the GitHub integration.
Confirm the newest production deployment carries your commit SHA and the endpoint answers: curl -s https://verity.basechainlabs.com/.well-known/agent.json | head -c 300
A push also redeploys the Railway seller. Confirm its log shows it connected afterwards.

Because there are no tests, prove a change on the live endpoint with a read-only call before calling it done. Never make a paid call (x402 or Stripe) just to test.

Things that bite

Prices live in four places that must stay in sync: public/index.html, the 402 body in api/_x402-gate.ts, the Virtuals ACP offerings, and the npm package README.
Agentic.market's "Validate endpoint" tool: use POST. GET returns the agent card (200) by design and the validator then says "no x402 setup".
Tavily is the search backend. If verifications start failing, check the Tavily credit first.
Removing the Railway volume wipes the seller's keyring on the next redeploy and takes it offline.

Verity

Add this server

Host a copy with our keys and logs.

Server facts

Tools

Questions

How do I install Verity?

Does Verity need an API key?

What transport does Verity use?

When was Verity last checked?

Documentation

VERITY — Real-Time Fact-Checking Agent

Verdicts

MCP Setup (Claude Desktop / Cursor)

Tools

API

Persistent Memory

A2A Agent Card

Making changes (maintainer guide)

Where things live

How a change goes live

Things that bite