Claim Grounding

Official registry AI and agents

Fact-check AI answers with cited sources. Pay per call in USDC on Base via x402.

What can you do with Claim Grounding?

  • Not legal, medical, financial or compliance advice. Not a certification.
  • English only. Public sources only; no paywalled or private documents.
  • Can return insufficient_evidence. Very recent news may lag.
  • No guarantee an email is delivered or read. No personal/private emails, no phone numbers.
  • Decision-makers are unknown unless a public source names them. Nothing is invented.

Install

Add this to your client's MCP configuration (Claude Desktop: claude_desktop_config.json; Cursor: .cursor/mcp.json; VS Code and others use the same "mcpServers" shape).

Remote (streamable-http)
Claude Code
claude mcp add --transport http claim-grounding 'https://claim-grounding.prospectintel.workers.dev/mcp'
JSON configuration (Claude Desktop, Cursor, VS Code)
{
    "mcpServers": {
        "claim-grounding": {
            "type": "http",
            "url": "https://claim-grounding.prospectintel.workers.dev/mcp"
        }
    }
}

Documentation

From the project's README on GitHub, refreshed weekly. Links open on GitHub.

Contents
  1. TruePoint Prospect Intelligence & Claim Grounding
  2. 30-second quickstart
  3. Prices (USDC per call)
  4. Sample request and response
  5. Errors
  6. What these tools don't do
  7. Discovery
  8. Support

TruePoint Prospect Intelligence & Claim Grounding

Pay-per-call APIs for AI agents. Pay USDC on Base per call with x402. No API key, no signup. People can pay by card instead.

  • Prospect Intelligence: work-email lookup and company research for sales agents.
  • Claim Grounding: checks factual claims against public sources and returns a verdict, confidence and citations.

Accuracy results: https://claim-grounding.prospectintel.workers.dev/accuracy (92 of 100 hard claims right on Deep verify, 0 confidently wrong; 38 of 38 found emails exactly right). Read the limitations there too.

30-second quickstart

Option A: Coinbase agentic wallet (awal)

npx awal@latest status          # sign in / check wallet
npx awal@latest balance         # needs USDC on Base
npx awal@latest x402 pay https://claim-grounding.prospectintel.workers.dev/v1/verify_claim \
  -X POST -d '{"claim":{"text":"The Eiffel Tower is in Paris"}}' --max-amount 1000000

--max-amount is in USDC atomic units (1000000 = $1.00), so you can never pay more than you set.

Option B: any x402 client. Call the endpoint with no payment. You get HTTP 402 with the price in the body and a payment-required header. Sign the payment with your x402 client and retry. Settlement uses the Coinbase CDP facilitator on Base (eip155:8453).

Option C: MCP. Point an MCP client (streamable HTTP) at:

  • https://claim-grounding.prospectintel.workers.dev/mcp
  • https://prospect-intelligence.prospectintel.workers.dev/mcp

tools/list is free. Tool calls return x402 payment instructions; the paid HTTP route does the work.

Option D: pay by card (people). Stripe checkout, no wallet needed:

Card prices are higher than agent prices because Stripe has a $0.50 minimum and per-charge fees.

Prices (USDC per call)

Claim Grounding: https://claim-grounding.prospectintel.workers.dev
MethodPathPriceWhat it does
POST/v1/extract_claims$0.05Split text into checkable claims
POST/v1/verify_claim$1.00Check one claim (Wikipedia)
POST/v1/check_answer$1.00Split an AI answer into claims and check each (Wikipedia)
POST/v1/deep_verify$0.75Check against six sources: Wikipedia, Wikidata, Google News titles, Europe PMC, FRED, SEC EDGAR. Async: poll GET /v1/jobs/:id (free)

Verdicts: supported, contradicted, outdated, mixed, insufficient_evidence.

Prospect Intelligence: https://prospect-intelligence.prospectintel.workers.dev
MethodPathPriceWhat it does
POST/v1/email$0.08, charged only when an address is foundOne work email for a name at a domain, with verification status, source and a send / send_with_caution / verify_first / do_not_send recommendation
POST/v1/basic$0.10research_company
POST/v1/enriched$0.75enrich_prospect
POST/v1/tools$0.75Any one named tool: research_company, research_person, find_decision_makers, analyze_marketing_opportunity, identify_buying_signals, enrich_prospect, score_prospect, generate_prospect_brief
POST/v1/deep$3.00Full prospect brief with a 0–90 score

Sample request and response

Request (real, paid, Oct 12, 2026):

npx awal@latest x402 pay https://claim-grounding.prospectintel.workers.dev/v1/verify_claim \
  -X POST -d '{"claim":{"text":"The Eiffel Tower is in Paris"}}'

Response (HTTP 200, shortened with …):

{
  "mode": "fast",
  "job_id": null,
  "claim": {
    "claim_id": "clm_14b3ffa736fd4fd1",
    "text": "The Eiffel Tower is in Paris",
    "span": { "start": 0, "end": 29 },
    "grounding_required": true,
    "verdict": "supported",
    "status_detail": "supported",
    "confidence": 0.95,
    "citations": [
      {
        "url": "https://en.wikipedia.org/wiki/Eiffel_Tower",
        "title": "Eiffel Tower",
        "quote": "The Eiffel Tower is a lattice tower on the …",
        "retrieved_at": "…",
        "provider": "wikipedia"
      }
    ],
    "rationale_short": "…"
  },
  "why": "…",
  "source": "https://en.wikipedia.org/wiki/Eiffel_Tower",
  "receipt": { "claim_hashes": ["sha256:…"], "evidence_urls": ["https://en.wikipedia.org/wiki/Eiffel_Tower"], "verdicts": ["supported"], "priced_usd": 1, "created_at": "…" }
}

Paid on Base: tx 0x839f…a901.

The unpaid first call (real, live) returns HTTP 402:

{
  "x402Version": 2,
  "error": "Payment required",
  "accepts": [{
    "scheme": "exact",
    "network": "eip155:8453",
    "amount": "80000",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "payTo": "0x485FfC037f02dDDc154A454a9cA89C4B1b29e25b",
    "maxTimeoutSeconds": 300,
    "extra": { "name": "USD Coin", "version": "2" }
  }]
}

(80000 = $0.08 for /v1/email. The asset is USDC on Base.)

Errors

StatusWhenCharged?
200SuccessYes
402No or invalid payment. Body and payment-required header list what to payNo
400Bad input, e.g. missing claim.text, or mode: "deep" sent to verify_claim (use /v1/deep_verify). On email: missing domain or namesNo
404Email lookup found no address (no_result), unknown path, or unknown job idNo
405Non-POST request to /mcpNo
409Card payment already used for a lookup (one payment = one lookup)No
422Email provider rejected the input (e.g. domain has no mail records)No
451Email lookup: the person opted out of data processing. Do not contact or storeNo
502 / 503Upstream source or email provider unavailable. Safe to retry laterNo

x402 only settles payment on a 2xx response, so failed calls cost nothing.

What these tools don't do

  • Not legal, medical, financial or compliance advice. Not a certification.
  • English only. Public sources only; no paywalled or private documents.
  • Can return insufficient_evidence. Very recent news may lag.
  • No guarantee an email is delivered or read. No personal/private emails, no phone numbers.
  • Decision-makers are unknown unless a public source names them. Nothing is invented.

Discovery

/docs · /.well-known/x402 · /openapi.json · /llms.txt · /.well-known/mcp/server-card.json on each host. Listed on agentic.market.

Worker source stays private; this repo is the public surface for agents and builders.

Support

Frequently asked questions

What is Claim Grounding?

Fact-check AI answers with cited sources. Pay per call in USDC on Base via x402.

How do I install Claim Grounding?

It runs as a remote server. In Claude Code: claude mcp add --transport http claim-grounding 'https://claim-grounding.prospectintel.workers.dev/mcp'. For other clients, paste the JSON configuration from this page into their MCP settings.

Does Claim Grounding need an API key?

Its registry entry lists no required key or secret. Some features may still need an account with the service it connects to.

Is Claim Grounding open source?

Its code is public on GitHub, but the repository does not declare a standard license.

Who maintains Claim Grounding?

It is published by truepointmarketingpartners-dotcom. AI.tn lists it but does not maintain or endorse it.

From the official MCP Registry. Listing is not an endorsement: review a server's code and permissions before giving it access to your data.