Specter Service¶

For devices like the Trezor One, air gapping is not possible. This means importing xpubs via USB - Specter permits this via the HWI which requires running a second instance of Specter on your local machine (i.e not your server).

1. Start by heading to Specter running on your server (you can use either Tor or LAN - if you are accessing your server over LAN the Launch UI button will open up the LAN interface for Specter - if you’re accessing over Tor it will open up the Tor interface).

2. Click on the cog in the top right, or Update your settings:

   

3. Click USB devices and then Remote Specter USB connection:

   

4. Click copy under step 2:

   

5. Now start Specter on your local machine (not your server) by either installing the application [here](https://specter.solutions) or run it in the background by following the instructions here.

6. Once it’s up and running, Head to the HWI settings here - http://127.0.0.1:25441/hwi/settings/

   

7. Paste in the domain that you copied from Specter running on your server and click Update

   

8. Now connect your Trezor One or other signing device to your local machine:

   

9. Head back to Specter on your server and click Save Changes

10. Click Test connection

11. You should see this along the top of the screen:

    

    Note

    At current time of writing, you must hit save before hitting test connection.

12. You can now click Add new device and select the type of signing device you’re using (in this case, a Trezor).

    

13. Name the device and click Get via USB:

    

14. You may be asked for your PIN and passphrase here, and you may need to confirm extraction on the signing device.

15. Specter will then begin extracting the public key(s) from your device:

    

16. You may not want all the default types of extended public key. Remove/keep the ones you want by clicking “edit” and “remove”.

17. Click “Continue”

18. You can now Add new wallet or create single key wallet:

    

    Tip

    If you want to create a multisig wallet, add another device first, and make sure you generated an xpub intented for multisig on the first device, then come back to this step.

19. Select the device (or devices if you are making a multisig wallet) that you want to use.

    

20. Name the wallet and select the key(s) you want to use.

    Tip

    (If you only have one key, it will automatically use that key)

21. Select Scan for existing funds if you have already used this wallet and wish to establish the transaction history, if this is a brand new wallet this is not necessary and should be deselected.

22. Click Create wallet:

    

23. If you selected “rescan” you can refresh the page and watch as your bitcoin node rescans the blockchain for your wallet’s history.

    Note

    This will be very slow if Specter is configured to connect to Bitcoin Core directly, and extremely fast if connecting via Electrs.

Specter is now setup to use your signing device!

This part of the guide will go over how to upload an xpub from a device that permits air gapping - in this case a Coldcard.

1. Power up the Coldcard, enter your pin and any passphrase necessary.

2. Go down to Advanced, MicroSD card, Export Wallet, Generic JSON:

   

3. Remove the SD card from your Coldcard and insert it into your local machine (not the server)

4. Go to Specter on your server, click “Add new device” and select Coldcard (or other air gap permitting device):

   

5. Name the device and click Upload from SD card:

   

6. Navitage to the SD card and select coldcard-export.json and click open:

   

7. You may not want all the default types of extended public key. Remove/keep the ones you want by clicking edit.

8. Click Continue:

   

9. You can now Add new wallet or create single key wallet.:

   Note

   If you want to create a multisig wallet, add another device first, and make sure you generated an xpub intented for multisig on the first device, then come back to this step.

10. Select the device (or devices if you are making a multisig wallet) that you want to use.

11. Name the wallet and select the key(s) you want to use.

    (If you only have one key, it will automatically use that key)

12. Select “Scan for existing funds” if you have already used this wallet and wish to establish its transaction history, if this is a brand new wallet this is not necessary and should be deselected.

13. Click Create wallet:

    

14. If you selected “rescan” you can refresh the page and watch as your bitcoin node rescans the blockchain for your wallet’s history.

Specter is now setup to use your signing device!