Claim Grounding

io.github.truepointmarketingpartners-dotcomPublished by GitHub account truepointmarketingpartners-dotcomv1.4.7Updated Oct 25, 2026

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

VerifiedStreamable HTTPWeb executableWeb Search & ScrapingKnowledge & Memory

Overview

AI-generated overview

A remote MCP server that splits text into factual claims and fact-checks them against public sources, returning verdicts, confidence and citations for a per-c全部

What you can do
Split a text or AI answer into atomic factual claims with type, span and check-worthiness rating. Verify a single claim against Wikipedia and get a verdict, confidence, reason, quote and source. Fact-check a whole answer claim by claim, adding Wikidata facts for dates, numbers and records. Run a deeper multi-source check against Wikipedia, Wikidata, Google News, Europe PMC, FRED and SEC EDGAR, with an asynchronous job to poll.
When to use it
Useful when an assistant produces factual answers that need citation-backed checking, or when a user wants to know whether a specific claim is supported, contradicted or outdated before relying on it.
Requirements
Remote streamable HTTP endpoint; no account or API key. Each tool call requires payment in USDC on Base via x402, settled through the Coinbase CDP facilitator; a card checkout option exists for people. Network access to the endpoint and its upstream sources.
Before you install
Every tool call costs money (for example $1.00 for verify_claim, $0.75 for deep_verify), so set a maximum amount in the client to avoid overspending. Payment is settled on a successful response only. Results are limited to public English sources and may return insufficient_evidence; they are not legal, medical or financial advice.

Installation

In SourceWeft

  1. Open Claim Grounding in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Web executable via Streamable HTTP. Remote servers run from the web runtime once configured in a workspace.

Use with an agent

Paste this prompt into Claude Code, Codex, Cursor or another agent — or into SourceWeft chat. The agent reads this server's install guide, shows you its publisher, endpoint and sign-in, and adds it to your client once you agree. Keys never go into a command.

Read https://sourceweft.com/mcp/io.github.truepointmarketingpartners-dotcom%2Fclaim-grounding/install.md and connect the MCP server it describes to my client. Before changing any config, show me its publisher, endpoint and sign-in method and wait for my OK. Never put an API key in a command or in a file I would commit; ask me where it should come from.

Read the install guide the agent follows

Other MCP clients

Add this to your client's mcpServers config.

{
  "mcpServers": {
    "claim-grounding": {
      "type": "http",
      "url": "https://claim-grounding.prospectintel.workers.dev/mcp"
    }
  }
}

README

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)

bash
npx awal@latest status          # sign in / check walletnpx awal@latest balance         # needs USDC on Basenpx 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:

ProductPriceLink
Claim check$0.50https://buy.stripe.com/00w5kDcBN8ri9Go6NP0co02
Deep verify$2.00https://buy.stripe.com/9B614n1X9bDuf0I2xz0co06
Email lookup$0.50https://buy.stripe.com/4gMcN56dp36Y05O4FH0co05

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):

bash
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 …):

json
{  "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:

json
{  "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

Source: README.md at commit 2ab74d0

Tools

4

extract_claims

Extract claims

Split a text (for example an AI-generated answer) into atomic factual claims. Each claim includes span, grounding_required, claim_type (number|date|quantity|quote|named_entity_fact|comparison|opinion|prediction|other), check_worthiness (high|medium|low), and the source sentence. Hedges are stripped, pronouns are resolved across sentences, and compound sentences are split. Questions, greetings, opinions and predictions are marked grounding_required false. Use before verify_claim. Price: $0.05 USDC on Base per call via x402; this MCP call returns payment instructions and POST /v1/extract_claims returns the claims. Read-only.

Parameterstextrequired

verify_claim

Verify claim

Check one factual claim against public Wikipedia sources and return a verdict (supported, contradicted, outdated, mixed or insufficient_evidence), a confidence score, a short reason, the supporting quote and the source URL. Says insufficient_evidence instead of guessing. Price: $1.00 USDC on Base per call via x402; this MCP call returns payment instructions and the paid HTTP route POST /v1/verify_claim returns the verdict. For a multi-source check use deep_verify. Read-only.

Parametersclaimrequiredsourcessources_only

check_answer

Check answer

Fact-check a whole answer: extracts every checkable claim and verifies each against Wikipedia, plus Wikidata structured facts for dates, numbers, quantities, ordinals and records. Returns per-claim verdict, confidence, quote, source URL, sentence span and suggested_correction (quoted only from cited sources when contradicted/outdated), plus an answer-level summary with overall_verdict, counts and problem_sentences. Abstained rather than guessed. Use to audit chatbot or RAG output. Price: $1.00 USDC on Base per call via x402; this MCP call returns payment instructions and POST /v1/check_answer returns the results. Read-only.

Parametersanswerrequiredsourcessources_only

deep_verify

Deep verify

Use when a claim is high-stakes, or when check_answer or extract_claims marks it unsure (their next_step gives the exact request). Verifies up to three claims against Wikipedia, Wikidata, Google News, Europe PMC, FRED and SEC EDGAR; returns verdict, confidence, evidence for and against with URLs, and flags contradictions. Async: poll GET /v1/jobs/{job_id} free. $0.75 USDC on Base via x402. Read-only.

Parametersanswerrequiredsourcessources_only

Version history

2
  1. v1.4.7LatestOct 15, 2026
  2. v1.4.4Oct 12, 2026

Score

90% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 daysRequired25 pts
  • Auth declaredRequired10 pts
  • Tools listedRequired15 pts
  • DescriptionRequired15 pts
  • Logo10 pts
  • Documentation15 pts
  • License10 pts

    Declare a license in the repository or the registry entry.