Trivia apps like Kahoot or pub-quiz apps ask general-knowledge questions, and "year in review" features (Spotify Wrapped-style chat stats sites) show counts, not games. Nobody turns a group's own history into a playable game show. Chat Trivia Night reads your group chat export, picks the funniest guessable moments, and builds four rounds (Who said it?, What year?, Finish the message, Emoji decode) that only your group can win, played on one phone passed round the table.
The data it runs on
The group's own chat export: WhatsApp's "Export chat" (without media) produces a plain .txt with one line per message, in an Android format ("12/01/2019, 09:20 - Name: text") or an iOS format ("[12/01/2019, 09:20:05] Name: text"). The demo parser handles both, plus multi-line messages, system lines, deleted and media-omitted messages. Telegram (JSON export) and iMessage (via third-party export tools) come later. Limits: date order differs by phone locale (day/month vs month/day), exports cap at a recent window on some phones, and names appear as saved contacts, so the same person can have two names. Fallback: the parser detects the date order from values above 12, and the host can merge duplicate names before the show.
1. The mission
Your group chat is the funniest book your friends ever wrote together. We turn it into a game night that pulls everyone off their phones and into the same room, laughing at who they used to be.
2. Why people can't resist it
Nostalgia with stakes. "Did I really say that in 2019?" is a jolt, and points make you care.
Only we can win this. The questions are impossible for outsiders, which makes the group feel like a club.
The rematch is built in. New messages every week mean a new round every week.
3. How it works for real
Import: the exported .txt is parsed on the device. Nothing is uploaded until members consent.
Consent: each member gets a link to opt in. Messages from people who have not opted in are never used, not even as wrong answers.
Filter: rules remove phone numbers, emails, account numbers, addresses and links; a fast classifier (Gemini Flash or DeepSeek via OpenRouter) removes health, money trouble, breakups, grief and anything about people outside the group.
Pick: a frontier LLM (Claude or GPT) ranks the remaining messages for "funny and guessable" and writes host lines. Only short excerpts are sent, never the whole chat.
Build: rounds are assembled in code: distractors from other members, year options near the true year, endings from other messages, emoji messages paired with what they replied to.
Host: optional TTS host voice reads questions; the game runs offline on one phone.
4. Cost per use
Pennies per game: one classification pass over a few thousand short lines (about $0.01) and one ranking and host-writing call (about $0.02). Parsing and scoring run on the phone.
Free: one show a month, 4 rounds. Party pass ($2.99 a month for the group): weekly shows, custom rounds, season leaderboard, TV mode.
5. Growth loop
Every show needs every member to consent, so one host invites the whole group. The final score card goes back into the same chat ("Kemi won Chat Trivia Night"), and each player belongs to other group chats that want their own show. Each month the host re-imports the chat for fresh rounds, and the season table, the Golden Mic title and the rematch history keep growing, so the group comes back every Friday to defend or steal the crown.
6. Risks and guardrails
Consent first: no opt-in, no messages. Anyone can pull their messages out at any time, even mid-season.
Sensitive content: health, money, relationships and grief are filtered by default; the host can hide any question before the show.
Data: parsing happens on device; only short excerpts go to models, with names replaced by placeholders; nothing is kept after the show unless the group saves it.
Harassment: no "roast" mode about people outside the chat; questions about absent members are blocked.
7. MVP build order
WhatsApp .txt parser (Android and iOS formats) with tests.
Consent list plus rule-based filters.
Who said it? and What year? rounds built in code, one-phone host screen with four buzzers.
LLM ranking for funny messages and host lines.
Share card and weekly "new round from this week's messages" reminder.