Simulator

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Try a SeedSigner in your browser. Its Python firmware runs locally with Pyodide. The simulator provides the display, buttons, camera and optional smartcards.

Choose your firmware below the device. SeedSigner is the original release. ShieldSigner adds SeedKeeper and Satochip support.

  • Display and buttons: use the device buttons, or the arrow keys, Enter and side keys 1, 2, 3.
  • Camera: scanning uses your webcam. In the wallet and walkthrough, QR codes pass between the on-page screens without a webcam.
  • Smartcards: simulated SeedKeeper and Satochip cards respond to the firmware's card commands.

Practice with test coins. Bitsaga Signet is a separate Bitcoin test network with a faucet and blocks about every 30 seconds. Its coins have no monetary value.

Keys stay in this browser. The firmware does not access the network. Opening the wallet or starting the walkthrough connects the page to signet.bitsaga.be for test coins, address balances, transaction confirmations and broadcasting. Keys, xpubs and descriptors are never sent there.

This browser is not a secure wallet. There is no secure element or air gap. Treat every seed entered here as public. Mainnet derives real mainnet keys and valid signatures, so never use a seed that protects real funds.

What is running

Firmware
…
Upstream
Tag
Commit
Interpreter
Pyodide , CPython compiled to WebAssembly

Each firmware is pinned to the newest release its project has published, by tag and by commit, rather than to a branch. A branch moves and can be rewritten out from under a rebuild; a published tag cannot.

The wallet zip this page loaded,

published sha256
what arrived here
published contents

The page is checking itself, so this is a convenience and not proof: only rebuilding the zip and comparing the hash is a check that does not depend on this page being honest.

What is in it

The upstream tree at the commit above, this repository's stand-ins for the hardware a browser does not have, and these pinned dependencies. Nothing else.

    Check it yourself: rebuild the zip · the same rebuild on a clean runner · tests · upstream's own tests · source · original source · latest release · device images · DoomSigner

    Never enter a seed phrase you rely on. Use a throwaway test seed. On Mainnet this page holds the real mainnet keys for whatever you give it, with no secure element under them: treat anything typed in as public.

    starting…

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    This is a simulator, and it starts on Testnet, so you can use it with Bitsaga Signet, my own test network. These are not real bitcoin. They exist only on that test network, cannot be sold or sent to anyone, and are worth nothing.

    Tap a menu to open it. Swipe up or down to move through the list.