Keep the time you wrote it.

Every time you save, TAPP records the fingerprint (SHA-256) of that version in Sigstore Rekor, a public transparency log. The text is never sent — only the fingerprint. Anyone can later confirm "this version existed on this date."

How to use (3 minutes)

1. Sign up for ¥500 a month (→ /en/signup)
2. Add your note username or RSS feed on /me (once)
3. Put your one line next to what you made

https://tapplog.com/t/YOURCODE

TAPP reads your feed daily, and stamps any post that contains your line. Edits add versions.

If you can write HTML, the same URL as a badge:

<a href="https://tapplog.com/t/YOURCODE"><img src="https://tapplog.com/t/YOURCODE.svg"></a>

Before publishing, or before handing over

Paste a draft or proposal on /press, or drop a file and stamp. The text never leaves the browser.

Video

Before uploading, drop the video file on /press and stamp. Put your one line in the description.

For developers (command line)

Node.js 20 or later. The key is on /me under Show key.

npx tapp-draft init              # store your key in ~/.tapp/config.json (once)
npx tapp-draft watch <file>      # watch saves and stamp each version
npx tapp-draft seal  <file>      # stamp once
npx tapp-draft status <file>      # local state and the chain on tapplog.com

Saving the same contents again sends nothing. If the network is down it says not sealed, and the next save tries again.

What stays / what doesn't

• Stays: the fingerprint of each version (64 chars) / the version number and the previous version's fingerprint / the fixed time / the ledger entry number
• Doesn't stay: the text / the file name / your name / how you typed

A fingerprint can't be turned back into text. Your text stays where it is: with you.

How to verify

1. take record R and random s from "disclosure" on the verify page
2. compute h = SHA-256("TAPP-COMMIT-V1" || s || JCS(R))
3. compare with the hashedrekord value in Rekor. Do this for each version.

About deletion

a fingerprint placed in Rekor cannot be removed. It cannot be turned back into text. Your text stays with you.