Proxae is a cryptographic timestamping service that produces verifiable proofs of when a document, text, or file existed. It is designed for individuals and organizations who need to establish anteriority of intellectual property, creative work, contracts, research outputs, or any digital artifact whose date of creation may later be contested. The platform uses a client-side architecture: SHA-256 hashes are computed directly in the user's browser via SubtleCrypto, ensuring that the original content never leaves the user's device. The hash is then anchored into the Bitcoin blockchain through OpenTimestamps, an open protocol that batches hashes into Bitcoin transactions for efficient and free anchoring at scale. Each proof generates a public verification page that can be independently audited by any third party against the Bitcoin blockchain, without requiring an account or trusting Proxae as an intermediary. Proxae offers three tiers. The free tier is available without an account and provides unlimited Bitcoin-anchored proofs, public verification links, and limited web page captures. A free authenticated tier adds proof history and folder organization. The Pro tier (€4.90/month) adds RFC 3161 timestamping by Sectigo qualified under ETSI EN 319 422 and recognized under the EU eIDAS regulation, an official PDF certificate, optional identity binding through Stripe Identity, and increased capture limits. A REST API is available for integrations.