Prooflater

Overview

Prooflater is a web application that lets users lock predictions, promises, and bets before outcomes are known. Claims are sealed, time-stamped, and cryptographically hashed — then revealed on a set date, unedited and verifiable. The tagline says it all: "Lock in your claims. Face the truth."

Challenge

People constantly make predictions and promises — about elections, markets, sports, personal goals — but there's no accountability. Claims get edited, memories get fuzzy, and "I told you so" arguments go nowhere. There was no simple, trustworthy way to prove what someone said before an outcome was known.

Solution

We built a prediction accountability platform with a three-step mechanism:

• Seal — Users submit a claim that locks immediately. No editing, no takebacks. Every claim is hashed with SHA-256 cryptography for tamper-proof verification
• Wait — A countdown timer runs from hours to years. Participants can discuss, but the sealed claim stays hidden. Automated reminders fire at 30 days, 7 days, 1 day, and 1 hour before reveal
• Reveal — When the countdown hits zero, an animated wax seal breaks and the original claim is revealed. Participants then vote: True, False, or Partially True

Key Features

• Cryptographic Integrity — SHA-256 hashing ensures claims cannot be tampered with after sealing
• Flexible Rooms — Create prediction rooms with customizable countdowns and invite participants via email or shareable links
• Community Voting — After reveal, participants vote on accuracy with True, False, or Partially True
• Shareable Outcome Cards — Download PNG outcome cards to share results across social media
• Slack Integration — Bot integration for team predictions and accountability (Pro/Teams)
• Animated Reveals — Dramatic wax-seal breaking animation for the reveal moment

Tech Stack

• Frontend: Next.js, TypeScript, Tailwind CSS
• Authentication: Email and link-based invites
• Cryptography: SHA-256 hashing for claim verification
• Real-time: Live countdown timers with push notification reminders
• Database: Supabase (PostgreSQL)
• Deployment: Vercel

Pricing Model

• Free — 5 rooms, up to 50 participants per room
• Pro ($9/mo) — Unlimited rooms, full AI features, Slack integration
• Teams ($15/mo) — Workspaces, SSO, audit logs for organizations

Results

• Launched as a fully functional prediction accountability platform
• Tamper-proof claim verification through cryptographic hashing
• Engaging reveal experience with animated wax-seal motif
• Scalable tiered pricing model from free users to enterprise teams