Fact check

Fact Check

Test a specific claim against evidence on both sides and issue a calibrated verdict.

Tools

Use available web search and URL-fetch tools. Prefer callable names ending in duckduckgo_search and web_fetch; client-added prefixes vary, so inspect the tools in the session. Without session tools, run the packaged CLI in an isolated environment:

uvx --python '>=3.10,<3.14' web-forager search "your query" --max-results 8 --output-format json
uvx --python '>=3.10,<3.14' web-forager fetch "https://example.com" --format markdown

If uvx cannot run packaged search, use ddgs without touching the current project environment:

uv run --no-project --python '>=3.10,<3.14' --with 'ddgs>=9.5.2' python - <<'PY'
from ddgs import DDGS
results = DDGS().text(query="your query", max_results=8)
for r in results:
    print(r["title"], r["href"], r["body"])
PY

If packaged fetch fails, use Jina Reader:

curl -s "https://r.jina.ai/https://example.com"

The workflow requires both search and fetch. If either capability is unavailable, return UNVERIFIED and name the missing capability.

Workflow

1. Extract the claims

Turn the user's statement into specific, independently verifiable claims. Separate compound claims. If wording is subjective, explain that it can be contextualized but cannot receive a factual verdict. Continue immediately when the claim is clear; ask for confirmation only when two plausible interpretations would change the evidence sought.

Complete when: every factual claim is precise enough that contrary evidence could disprove it.

2. Seek support

Search for primary evidence that would confirm each claim. Use direct paraphrases, official statements, and queries for the exact metric or event.

Complete when: each claim has the strongest available supporting evidence, or the absence of support is recorded.

3. Seek contradiction

Actively search for counterevidence, corrections, alternative measurements, and credible disagreement. Do not treat failure to find a debunk as confirmation.

Complete when: every claim has received a genuine adversarial search, not merely a second confirming query.

4. Read and weigh sources

Read 2–4 of the most authoritative sources across both sides. Evaluate authority, specificity, recency, independence, and conflicts of interest.

Complete when: the decisive evidence addresses the exact claim and all material source limitations are known.

5. Deliver the verdict

Use this scale:

• CONFIRMED: multiple authoritative sources agree and no credible contradiction survives review.
• LIKELY TRUE: strong support remains, with minor gaps or caveats.
• UNVERIFIED: strong evidence is unavailable in either direction.
• DISPUTED: credible sources materially disagree.
• FALSE: strong evidence contradicts the claim and support is weak or absent.

Default to a compact verdict for one claim:

1. state the claim and verdict first;
2. explain the decisive support and contradiction in 2–4 sentences;
3. add only caveats that could change how the verdict is understood;
4. cite 2–4 decisive sources, annotated by role.

For multiple extracted claims, repeat the compact block for each. Use a source-by-source account only when the user requests it or a material conflict cannot be explained compactly. State explicitly when one side produced no evidence.

Complete when: every extracted claim has a verdict, both search directions are accounted for, decisive evidence is cited, and confidence matches the limitations.