truthcheck

name	truthcheck
description	Verify claims, fact-check content, check URL trustworthiness, and trace claims to their origin using the TruthCheck CLI. Use when: (1) user asks to fact-check or verify a claim, (2) user wants to check if a URL/source is trustworthy, (3) user wants to trace where a claim originated, (4) user asks about misinformation or content verification. Requires: pip install truthcheck

TruthCheck Skill

AI content verification CLI. Verify claims, check URLs, and trace misinformation.

Commands

Verify a claim

truthcheck verify "claim text" --llm gemini

• Returns TruthScore 0-100 with breakdown (publisher, content, corroboration, fact-checks)
• --llm is optional but improves accuracy
• Add --json for structured output

Check URL trustworthiness

truthcheck check https://example.com
truthcheck check "text with multiple URLs"
truthcheck check -f file.txt

• Detects hallucinated URLs that don't exist
• Rates publisher credibility

Trace a claim to its origin

truthcheck trace "claim text"           # balanced, ~1-2 min
truthcheck trace "claim text" --quick   # fast, ~30 sec
truthcheck trace "claim text" --deep    # thorough, ~3-5 min

• Finds original source and builds propagation tree

Look up a publisher

truthcheck lookup "publisher name"

Sync publisher database

truthcheck sync

Run periodically to keep publisher ratings current.

Interpreting TruthScore

Score	Label	Meaning
80-100	TRUE	Strong evidence supports the claim
60-79	POSSIBLY TRUE	Some supporting evidence, inconclusive
40-59	UNCERTAIN	Mixed or insufficient evidence
20-39	POSSIBLY FALSE	Evidence leans against the claim
0-19	FALSE	Strong evidence contradicts the claim

LLM Integration (Optional)

TruthCheck works without any LLM, but adding --llm improves content analysis accuracy.

truthcheck verify "some claim" --llm gemini    # recommended, fast & free tier
truthcheck verify "some claim" --llm openai    # GPT models
truthcheck verify "some claim" --llm anthropic # Claude models
truthcheck verify "some claim" --llm ollama    # local models, fully offline

Privacy: API keys are stored in your local environment only. TruthCheck never sends your keys to any external service — they are used solely for direct API calls to the respective LLM provider.

Environment Variables

Variable	When needed	Description
GEMINI_API_KEY	--llm gemini	Google AI API key (free tier available)
OPENAI_API_KEY	--llm openai	OpenAI API key
ANTHROPIC_API_KEY	--llm anthropic	Anthropic API key
BRAVE_API_KEY	--search brave	Brave Search API key

No keys needed for --llm ollama (runs locally) or default DuckDuckGo search.

Tips

• Verify commands can take 15-60 seconds depending on search results
• Without --llm: basic scoring using publisher reputation, corroboration, and fact-checks
• With --llm: adds AI content analysis for better accuracy
• --search brave gives better search results than default DuckDuckGo
• For batch verification, loop through claims individually