Privacy Policy
Last updated: 21 September 2026
The short version. Decoder reads email, so it is worth being exact. A message is sent to our server only when you press a button, only that message, and it is not stored. We never receive the contents of your mailbox, and we never receive the email address of the person you are writing to. There are no accounts and no tracking.
When anything is sent at all
Decoder does nothing until you click one of its two buttons. It does not read your inbox in the background, does not index your mail, and does not act on messages you haven't asked it about. Opening Gmail with Decoder installed sends nothing.
What is sent when you click “What's it asking?”
- The text of that one message, with the quoted reply history stripped out before it leaves your browser.
- Up to two earlier messages in the same thread, as context. Nothing older, and nothing from any other conversation.
- A random installation ID — a UUID created when you install the extension. It is not derived from anything about you and is not linked to a name, email address or Google account. It exists to count how many messages this installation has used.
- Your licence key, if you have one.
What is sent when you click “Adjust”
- The draft you wrote, with any quoted history stripped.
- Which of the four registers you chose — warmer, more direct, more formal or shorter.
- The note you have written about that recipient, if any — the note text only. See below.
- The installation ID and licence key, as above.
Email addresses never leave your computer
Decoder uses the sender's or recipient's address to look up your own note about that person. That lookup happens entirely inside your browser. The address itself is never sent to our server — only the note text you wrote, and only when you adjust a message to that person.
One honest caveat: if an email address appears inside the body of a message you decode, or inside a draft you adjust, it travels with that text like any other word in it. We do not extract it, store it, or do anything with it — but we are not going to claim we scrub message bodies when we do not.
What happens to the message
Our server forwards it to Anthropic, which runs the AI model. We do not store the message, the draft, or the result. They pass through and are gone. Our server keeps no log of message contents.
Anthropic's handling of that data is governed by their privacy policy. Under their commercial terms, data sent through the API is not used to train their models.
What we store, and for how long
- A count against your installation ID. A number and nothing else — how many messages this installation has used. The free allowance is a lifetime one rather than a monthly reset, so the number is kept for as long as the allowance needs enforcing. It is a count, not a history.
- A count against a salted one-way hash of your IP address, to stop automated abuse. We never store the address itself. The salt is random, changes every day, and is discarded along with that day's counts after two days — after which those hashes cannot be traced back to an address by anyone, ourselves included.
- A cached licence-validity result if you subscribe, for up to an hour, so we are not re-checking your subscription on every message.
We do not store message text, drafts, subject lines, email addresses, recipient notes, or any record of who you correspond with.
What stays on your own computer
Your notes about how each person likes to be written to live in your browser's local extension storage and are never uploaded. The same is true of your installation ID and licence key. Uninstalling Decoder removes all of it.
Because those notes are stored locally and not backed up, they do not follow you to another computer — that is a deliberate trade, and the reason is that a server-side record of how thousands of people describe their colleagues is not something we want to be holding.
What Decoder does not do
- No accounts, no passwords, no email addresses collected by us.
- No analytics, no advertising, no third-party trackers.
- No reading, scanning or indexing of your mailbox.
- No record of who you email or what you email them about.
- No selling or sharing of data. There is nothing meaningful to sell.
Payments
Payments are handled entirely by Lemon Squeezy, who act as the merchant of record. They collect your billing details; we never see your card. We only receive a licence key and whether it is currently valid.
Permissions the extension asks for
- Access to mail.google.com — to place the two buttons and read the message you click them on.
- Storage — to keep your installation ID, licence key and recipient notes locally.
- Access to our own API — to send a message for decoding or a draft for adjustment.
Decoder does not request access to any other website.
Children
Decoder is not directed at children under 13 and we do not knowingly collect information from them.
Changes
If this policy changes materially, the date at the top will change and the updated version will be published here before the change takes effect.
Contact
Questions about any of this: decoder@cdt.enterprises