Timestamp Any Document
on Bitcoin
Prove your documents existed at a specific point in time. Pay with Lightning. No account needed.
Prove your documents existed at a specific point in time. Pay with Lightning. No account needed.
Three steps to immutable proof of existence
Generate a SHA-256 hash of any file locally on your machine. Your document never leaves your device.
Send the hash to our API. Pay with any Lightning wallet. No accounts or signups required.
Your hash is anchored in a Bitcoin transaction with an OP_RETURN output. Verification is free, forever.
# Hash a file
sha256sum document.pdf
# Timestamp it (returns Lightning invoice)
curl -X POST https://certvera.com/api/l402 \
-H "Content-Type: application/json" \
-d '{"action":"l402_timestamp","hash":"a1b2c3..."}'
# Verify later (free)
curl -X POST https://certvera.com/api/l402 \
-H "Content-Type: application/json" \
-d '{"action":"l402_timestamp_verify","hash":"a1b2c3..."}'
Built for developers, agents, and anyone who needs proof
Pay per use with Lightning. No signups, no OAuth, no API keys to manage.
Starting at 25,000 sats (~$17). Price adjusts based on current Bitcoin network fees. Pay instantly with any Lightning wallet.
Once timestamped, anyone can verify a hash for free. Immutable Bitcoin proof.
L402 protocol support means any AI agent with a Lightning wallet can use CertVera.
Pay per use. Price adjusts with Bitcoin network fees. Currently ~$17-$24.
Each timestamp is anchored to the Bitcoin blockchain via an on-chain transaction. Pricing includes a fixed service fee plus the estimated Bitcoin network fee. The exact price is shown in the Lightning invoice before you pay.
CertVera speaks L402 natively. Any agent with a Lightning wallet can timestamp documents without human intervention.