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Halowerk Claim Checker
x402
Halowerk Claim Checker is a paid API for AI agents from tools.halowerk.com, paid per call via x402, $0.008/call, status unknown (last checked 2026-09-15).
Fetches given sources, splits them into sentences, finds passages with the highest term overlap to a claim, returns verbatim quotes with citations, detects negation, and checks whether numbers from the claim appear in the sources.
Price / call$0.008
Success—
StatusUnknown
How this service works
Holt die genannten Quellen, zerlegt sie in Saetze und sucht die Fundstellen mit der hoechsten Begriffsdeckung zur Behauptung. Liefert woertliche Zitate mit Quellenangabe, erkennt Verneinung und prueft, ob die Zahlen aus der Behauptung in den Quellen vorkommen. Bewertet, was in den Quellen steht, nicht was zutrifft.
Output
Returns the most relevant verbatim sentences from each source ranked by term overlap with the claim, with source attribution, a negation indicator per passage, and a check on whether numerical values from the claim appear in the source text.
Example use cases
Journalist verifying a statistic
“I'm writing an article claiming that 'global EV sales surpassed 10 million units in 2022.' Can you check these three sources — https://iea.org/ev2023, https://statista.com/ev-sales, and https://bloomberg.com/ev-report — and pull the exact sentences that confirm or contradict that number?”
Researcher fact-checking a policy claim
“Does the source at https://who.int/tobacco-report back up the claim that 'smoking causes 8 million deaths per year'? Show me the verbatim quotes with the highest match and let me know if anything in the text contradicts or negates that figure.”
Content moderator checking viral misinformation
“Someone is sharing the claim 'The vaccine reduces hospitalizations by 95%.' Can you fetch these two sources — https://cdc.gov/vaccine-efficacy and https://nejm.org/vaccine-study — and find the passages with the highest term overlap to that claim, noting whether any of them negate it?”
Technical details
Endpoint
POSThttps://tools.halowerk.com/v1/claim/checkWhen to prefer
Choose this endpoint when you need to ground-check a specific claim against one or more provided source URLs and want verbatim quotes with citations rather than a generative summary. It is especially useful when numerical accuracy and negation detection matter, such as fact-checking journalism, academic citation verification, or misinformation detection. Prefer it over generic search or summarization APIs when the sources are already known and literal quotation with term-coverage scoring is required.
Side effects
- Source URL unreachable or returns non-200 — source is skipped or error reported
- Source is behind a paywall or requires authentication — content cannot be fetched
- Claim contains no overlapping terms with source content — no relevant passages returned
- Source is in a language other than the claim language — coverage may be low
- Numerical values in claim not present verbatim in sources — number mismatch flagged
- Malformed or empty claim text — validation error returned
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| claim | string | Die zu pruefende Behauptung |
| sources | array | Bis zu acht Quell-URLs |
Tags
x402
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