Xmark is a browser extension for marking your X/Twitter posts to the Bitmark (BTM/MARKS) blockchain, and relaying it to the nostr network. Anytime you post/respost something on X, the extension will send a request to our server to mark the post in a transaction in the blockchain.

The extension works quietly in the background and its log can be viewed in the browser console. The entire content of the post will be stored in our server (including images/videos) and can be easily downloaded by requesting the needed hash. The blockchain stores the hash of the (XMK) text file containing the full text, metadata, and media links of the post; the link (xmark.cc) together with the hash of our HTTPS certificate; and a short (92 character) description.

After the post has been sent to our Bitmark node, it should be in the blockchain in a few minutes (2 min target time), and you can see it with the relevant hash in a BTM block explorer, as well as a post in our nostr bridge. Linkmark is a related project that specifies the marking protocol and through that site one can search for marked data using key words or hashes.

Chrome extension
Firefox extension