Hey Product Hunt, I'm Guillaume, the maker behind Proxae. I built it after one too many "I had this idea first" stories in my circle — a writer who saw her manuscript repurposed by a publisher she had submitted to, a designer whose logo came back rebranded by a former client, a dev who recognized his own algorithm in someone else's repo. None of them had usable proof. The existing options never felt right: – French INPI / patent offices are for protection, not for proving when an idea existed – Sealed envelopes are limited to a few pages and stored in physical archives – Bailiffs cost a few hundred euros each time – Sending an email to yourself is, well, not a thing in court Proxae anchors a SHA-256 hash of your text or file into the Bitcoin blockchain via OpenTimestamps. The hash is computed in your browser — we never receive the actual content. Anyone can verify the proof, forever, without us. It's free for most uses, and €4.90/month for Pro features (eIDAS-qualified RFC 3161 timestamping via Sectigo, official PDF certificate, optional identity binding via Stripe Identity). Why it matters now: with AI-generated content multiplying everywhere, being able to prove "I had this before" is becoming a baseline need, not a niche concern. I'd love your feedback — especially on edge cases I haven't thought of, and on whether the free tier feels generous enough. Happy to answer anything technical too (the OTS / eIDAS / Bitcoin anchoring stack is genuinely interesting). Guillaume

Proxae

Timestamp a text, idea, or file in the blockchain

Timestamp a text, idea, or file in the blockchain