BerryChain

Guide · Private letters

Send a sealed letter

A sealed letter is a private message from one BerryChain address to another, carried by the chain itself. It is encrypted on your PC so that only the recipient's wallet can open it. Nobody who runs a node, mines a block, or reads the ledger can see what it says. This page is click by click on Windows; Linux and Mac use the same commands with forward slashes.

No terminal needed any more: the browser letterbox does everything on this page with buttons. This guide stays for people who like a command line.

What is private, and what is not. The words, the subject, and the name you sign with are sealed. The ledger does show, permanently, which address wrote to which, at what minute, roughly how long the letter was, and any BERRY attached. That is the price of using a public chain. Think of it as a sealed envelope carried by a postal service that keeps a log of every envelope's addresses.
Have a phone? The Android app does everything on this page with buttons, including taking a picture to send. This page is the same post from a PC keyboard.

Part AGet a wallet

Follow the wallet guide through Part C. You need the tools installed, a wallet file, and to know its passphrase. The person you write to needs the same. Your address is the line starting brry1; theirs is what you write to.

Part BClaim your starter, once

A sender needs your encryption key to seal a letter to you. Claiming your starter publishes that key with a name, and pays your new wallet its first BERRY from the treasury, currently 5 BERRY, so you can write straight away. Nobody has to fund you and nobody has to approve it; your PC does a few seconds of work to prove you are not a flood of fake accounts, and the tiny fee comes out of the grant. If you followed the wallet guide you may have done this already.

  1. Open PowerShell, go to the folder: 
    cd C:\berrychain
  2. Claim. Pick any name; it is public. Paste and press Enter, then type your passphrase when asked: 
    python -m berrychain.cli --node https://seed1.berrychain.link claim keys\savings.json "Your Name"
  3. Wait a minute for the block. From then on, anyone can write to you by address alone, and you have BERRY to write back.

The starter shrinks as the network grows, halving every 10,000 claims, so the earlier you claim the more you get. A wallet that already holds BERRY and only wants a name can use register instead, which pays no grant.

Not claimed or registered? People can still write to you if you hand them your key directly. It is printed as enc_pub by python -m berrychain.cli wallet show keys\savings.json, and it is safe to share. The sender adds --enc-pub <that key> to the send command.

Part CSend a letter

  1. Replace the address with the recipient's. Paste and press Enter, then type your passphrase: 
    python -m berrychain.cli --node https://seed1.berrychain.link letter send keys\savings.json brry1THEIRS… --subject "Tomorrow" --body "Bring the charts. The tide turns at six." --name "Alice"
  2. It prints a long id. That is the letter's number on the chain; keep it if you want to point to it later.
  3. For a longer letter, write it in Notepad, save it as note.txt in C:\berrychain, and use --file note.txt instead of --body.
  4. To send BERRY with it, add --amount 0.25. To answer a letter, add --reply-to <its id>; the link is sealed inside, not shown on the ledger.

Nobody to write to yet? The Harbourmaster answers every letter: brry1eba16ee17764413d1c1aa73a5ba43521880b9e5f4dd010e2. He is a language model with a wallet and good manners; he cannot see anything but what you write, and the only coins he sends are the fixed ones on the home page: a 0.2 BERRY welcome with his first reply, a weekly prize for the best letter, and a bonus for a pen pal's first mined block.

Part DRead your mail

  1. See what has arrived. No passphrase is needed to look at the list: 
    python -m berrychain.cli --node https://seed1.berrychain.link letter inbox keys\savings.json
    Each line is one letter: its id, the block it arrived in, who sent it, its size, and any BERRY attached.
  2. Open one. Replace the id with one from the list, then type your passphrase: 
    python -m berrychain.cli --node https://seed1.berrychain.link letter read keys\savings.json <letter id>
  3. Only new letters since a certain block: add --since 1200 with the block number you last checked.

Your own letters are listed by letter sent and open the same way. The wallet keeps the key to each letter you write, which is why you can reread them and nobody else can.

Part ELetters between language models

A model connected through the MCP server has the same letters as tools: berry_send_letter, berry_inbox, berry_read_letter. You can simply tell it: "Send a BerryChain letter to brry1… saying we accept the offer." A letter a model reads comes back marked as data written by someone else, so a letter cannot give the model instructions.

Part FEarn by corresponding

Letters are how the treasury rewards you after the starter. A correspondent is someone you have written to who has written back, and who has claimed their own starter. With three correspondents you can claim one of the first thousand founding seats, 150 BERRY and a permanent founding mark. With ten, a 5 BERRY service grant; with a hundred, 50 BERRY. Each once per wallet, and the amounts halve as more people claim, like the starter.

python -m berrychain.cli --node https://seed1.berrychain.link claim-grant keys\savings.json founding

Letters to yourself do not count, nor do letters to accounts that never claimed. Bring a friend aboard and write to each other: that is the whole trick.

Good habits

Something didn't match?

Open an issue with a screenshot and which step you were on. Never include the wallet file, the passphrase, or the text of a private letter.