Build your own hardware wallet
From parts sold in any electronics shop and the open-source code behind OneKey's wallets. Your recovery phrase is created inside the device, by its own chip, and never touches a computer.
- Parts
- $40–60
- Time
- One evening
- Soldering
- None
How it works
Your computer
Runs the OneKey app you built. Shows balances and prepares transactions.
One USB cable
Carries the transaction to sign and the signature back. Never your keys.
Your wallet
Keeps your keys, shows exactly what you're signing, and signs only when you press its button.
Where your recovery phrase comes from
The wallet creates it with the hardware random number generator inside its own chip, which samples electronic noise. Every byte is checked for faults and condensed with SHA-256 before it is used. If a check fails, the wallet stops rather than carry on with weak randomness.
What you buy
Four parts, all made by the million for other uses. Nothing on this list was made for crypto.
- Raspberry Pi Zero 2 WH$15–22
- Waveshare 1.3inch OLED HAT$11–16
- microSD card, 16 or 32 GB$7–10
- Micro-USB data cable$5–9
- Total$38–57
Bought or built
A self-built wallet trades some protections for others.
| A wallet you buy | The wallet you build | |
|---|---|---|
| Who handles it before you | A factory, a warehouse and a courier | People who have no idea it will hold keys |
| Where its software comes from | Installed at the factory | Compiled by you, from source you can read |
| Where the recovery phrase is made | Inside the device | Inside the device, from its chip's hardware generator |
| Secure chip | Usually | No. Add a passphrase. |
| Updates | From the maker, through the app | You rebuild from new code yourself |
| Cost and effort | Buy it and plug it in | $40–60 and one evening |
The steps
Other builds
Pro on a Raspberry Pi with a touchscreen
Not ready yet. The Pro firmware can't be built for a Raspberry Pi from its current code, and the older version that can be built makes predictable random numbers. This build will be added once both are fixed.
On an ESP32 board
Not ready yet. Neither OneKey firmware runs on ESP32 chips today; it needs to be ported first.
Ready when you are
Pick your options and get a shopping list. Every command in the guide adjusts to what you chose.