chitti-news-factcheck

name	chitti-news-factcheck
description	Fact Checker Agent — cross-references a news article against ≥2 other trusted RSS sources in our DB and returns a verdict (verified / partial / disputed / unverified) with rationale. Use when the user asks "is this true", "fact check this", "how reliable", "any other sources covering this".

Chitti News — Fact Checker Agent

When to invoke

• User asks: "is this true", "fact check", "any other sources", "how reliable", "trustworthy"
• The frontend's 🛡️ Fact Check button is tapped
• A backend route in routes/news.py:article_factcheck is called

Verdicts (4 tiers)

Verdict	Symbol	Color	Meaning
verified	✅	green	≥3 distinct trusted sources agree on the headline + key facts
partial	🟡	amber	2 sources cover it; broad facts match, details differ
disputed	⚠️	red	1 other source found, headline diverges OR contradicts
unverified	❔	muted	No cross-source corroboration yet (single-source story — could be hyperlocal or just-breaking)

Algorithm (v1, no LLM required for matching)

1. Normalize the article title: lowercase, collapse whitespace.
2. Window to the last 48 hours of articles in the same language.
3. Score with rapidfuzz.fuzz.token_set_ratio().
4. Cluster at score ≥ 70.
5. Count distinct source_slug values among matches (excluding the original).
6. Cache result in news.fact_checks for 6 hours; re-running returns the cache.

The rationale (one-line EN + one-line HI explanation of the verdict) is template-rendered in v1 and stored alongside the verdict. A v2 upgrade to DeepSeek-generated rationale is planned for ambiguous match scores only — see TODO.md and PROMPTS.md §2.

Trust assumption

Every source we ingest from data/sources.json is treated as "trusted" (public RSS feeds from established Indian news outlets). The fact-check verdict is about agreement among sources, NOT about whether any one source is correct — Chitti News does not editorialise.

Implementation

• backend/services/news_factcheck.py → factcheck(db, article_id, force=False)
• DB cache key: (article_id) unique
• Returns {ok, verdict, symbol, color, confidence, matched_sources, rationale_en, rationale_hi, checked_at}

Caveats

• Title-similarity matching can yield false negatives when two outlets use very different wordings for the same event (e.g. "RBI cuts repo rate" vs "Central bank lowers benchmark"). v2 plans: switch to entity
  • verb extraction via DeepSeek.
• "verified" is not a truth claim — it's a "many outlets are saying this" claim. Always render with the disclaimer "verify on the original source link before sharing".