Claim Grounding

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confidence, quote, source URL, sentence span and suggested_correction (quoted only from cited sources when contradicted/outdated), plus an answer-level summary with overall_verdict, counts and problem_sentences.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.

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.

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. Up to 3 checkable factual claims (opinions skipped) get a next_step: a ready-to-send quick_check request ($0.15, fast verdict with 1-2 sources), with deep_verify ($0.75) and verify_claim ($1.00) bodies in next_step.alternatives, so you can check them in one more call. 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.

Fast, low-cost check of ONE factual claim. Returns verdict supported, contradicted or unsure, a confidence score, a short reason and 1-2 public sources (Wikipedia, plus Wikidata structured facts where they apply) with quote and URL. Synchronous. Cheaper and faster than deep_verify; use it on the claims extract_claims returns (its next_step gives the exact body). Unsure or low-confidence results include a next_step to deep_verify. Price: $0.15 USDC on Base per call via x402; this MCP call returns payment instructions and POST /v1/quick_check returns the verdict. Read-only.

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.