Using opentimestamps with a remote node

Install opentimestamps with pip3 install opentimestamps-client.

To make the script globally accessible, add the directory to your path:

echo 'export PATH="/Users/billerickson/Library/Python/3.9/bin:$PATH"' >> ~/.zshrc

Then reload your shell configuration:

source ~/.zshrc

Now that ots is installed and ready to go, it’s time to connect your remote node. Create a bitcoin.conf file in ~/Library/Application Support/Bitcoin/ and put this in it (using info from your node).

[rpc]
rpcuser=YOUR_BITCOIND_RPC_USERNAME
rpcpassword=YOUR_BITCOIND_RPC_PASSWORD
rpcconnect=YOUR_BITCOIND_IP
port=8332

Usage

Creating a timestamp:

ots stamp README.md

You’ll see that README.md.ots has been created with the aid of three remote calendars. We can’t verify it immediately however:

$ ots verify README.md.ots
Assuming target filename is 'README.md'
Calendar https://alice.btc.calendar.opentimestamps.org: Pending confirmation in Bitcoin blockchain
Calendar https://bob.btc.calendar.opentimestamps.org: Pending confirmation in Bitcoin blockchain
Calendar https://finney.calendar.eternitywall.com: Pending confirmation in Bitcoin blockchain

It takes a few hours for the timestamp to get confirmed by the Bitcoin blockchain; we’re not doing one transaction per timestamp.

Once it has been verified, you can run the verification against your own node:

ots verify README.md.ots
Assuming target filename is 'README.md'
Success! Bitcoin block 875764 attests existence as of 2024-12-21 CST

If you do not have a node configured, you can pass the –no-bitcoin flag to get the block and merkleroot, then verify it yourself on mempool.space:

ots verify --no-bitcoin README.md.ots
Assuming target filename is 'README.md'
Got 2 attestation(s) from cache
Not checking Bitcoin attestation; Bitcoin disabled
To verify manually, check that Bitcoin block 875764 has merkleroot 018eb583eeffe332b423107751d62052c56c5be4a9c6caf71758547e568fe719
Not checking Bitcoin attestation; Bitcoin disabled
To verify manually, check that Bitcoin block 875837 has merkleroot a4e628ddacab58ed698d35b230857cfcc2da57dc9817fa11c195efc00226b066