Integrating-specter.md

Using Specter Desktop as Initiator & Finalizer

Scenario Description: Specter Desktop acts as an Initiator and Finalizer; Gordian Cosigner acts as a cosigner; other users cosign by other means.

Creating a Descriptor for Specter Desktop

There are two ways to create this descriptor: you can either export the "descriptor" from the Accounts tab of Gordian Cosigner, or you can export the individual origins and public keys from the Cosigners tab and build a complete descriptor on your own.

Once you have creating a proper descriptor, you'll be able to use it for a variety of functions on Specter Desktop.

Creating a Descriptor from Accounts Information

The export function on the Accounts tab in Gordian Cosigner will produce text like the following:

{"blockheight":0,"descriptor":"wsh(sortedmulti(2,[a890879a\/48h\/1h\/0h\/2h]tpubDEzcZKQ5N3ymDtUv6ekeyiESkAr5BwKSFdL4afXDDLf2f7KhJ5cyr2XrKqHwYutxYEVoUcDxdTFM2qPvvr1nwaa7HtAeJN4b4RuGRhPSS83,[90081696\/48h\/1h\/0h\/2h]tpubDFhpmpiYsqtknPaom1M3hDM17gm4UPhCbjqj33k27tGf1bHWMcfyuNPLYozB1uzaaYyFz3CxJU7wzBdQ1FiRSfMaftbUYHgMZ5SrV5FcxV1))","label":"2 of 2"}

To use that descriptor with Specter Desktop, you must do the following:

Click Add new wallet -> Import from wallet software and paste the descriptor into the field:

Specter Desktop will automatically recognize the cosigners. Click import wallet.

On success, Specter Desktop will create a wallet and prompt you to back it up.

Creating a Descriptor from Cosigners Information

Alternatively, you have everything you need in the Cosigners tab. You can go to each individual cosigner and incorporate all of that information to create your descriptor with Specter Desktop.

For example, look at the "Cosigner Detailer" for the first cosigner above and tap the "Text" button, which will give you an xpub that Specter Desktop can understand:

Origin:

a890879a/48h/1h/0h/2h

Public key:

tpubDEzcZKQ5N3ymDtUv6ekeyiESkAr5BwKSFdL4afXDDLf2f7KhJ5cyr2XrKqHwYutxYEVoUcDxdTFM2qPvvr1nwaa7HtAeJN4b4RuGRhPSS83

You'll need to repeat this for each cosigner:

Click Add new device -> Paste xpub

You'll have to paste the xpub in this form:

[a890879a/48h/1h/0h/2h]tpubDEzcZKQ5N3ymDtUv6ekeyiESkAr5BwKSFdL4afXDDLf2f7KhJ5cyr2XrKqHwYutxYEVoUcDxdTFM2qPvvr1nwaa7HtAeJN4b4RuGRhPSS83

On success, Specter will show the xpub in Multisig Sig (Segwit) section. Click Add Device.

After both cosigners are imported as devices, you can create a new wallet. Click Add new wallet -> Multisignature wallet. Specter will list all available devices (cosigners). You select your cosigners and click Continue.

In this section you choose your wallet name, multisig quorum and press Create wallet.

This should generate the same descriptor as created by Gordian Cosigner, but this methodology allows you to create it from the individual keys on your own.

Testing Addresses on Specter Desktop

Open your wallet and click Addresses:

You can compare these in Gordian Cosigner by going to the Accounts tab, clicking the account in question and choosing "Address Explorer". Just click through the first few receive addresses; they should match the first few derived addresses by Specter.

Creating PSBTs on Specter Desktop

You can use Specter Desktop to be a transaction coordinator, acting as an Initiator for your multisigs.

First, make sure to run the Blockchain rescan in Settings to see all of the available funds in your wallet

Next, click Send and fill out the Recipient address, amount and click Create unsigned transaction.

Specter Desktop will create a (raw) PSBT for you in Transaction details. Save it as a binary PSBT and then import it into Gordian Cosigner.

Here's what that PSBT looks like:

cHNidP8BAF4CAAAAAfqEYfU2gO7ROSK/GAs+SXJrHbjHZjZOKilk/YFB5hQFAAAAAAD9////AXQOAAAAAAAAIgAgPj5KLRi8y2BNNdMG2/aPuYvQ0GlQKftHppS4TXzSz6AAAAAAAAEBKxAnAAAAAAAAIgAg1U1vfMTGNj97nxnV3wmGAcfWh3exbogY9AOtA5/gwQUBBUdSIQLOC/QwsxNzaSK9oogBjQcKO2TBC9+bIfBqiEl+8u1F0SEDM35b7S6ogiU3QeAHszUe3iS6CbBd7fY91+bow6DSb2hSriIGAs4L9DCzE3NpIr2iiAGNBwo7ZMEL35sh8GqISX7y7UXRHKiQh5owAACAAQAAgAAAAIACAACAAAAAAAAAAAAiBgMzflvtLqiCJTdB4AezNR7eJLoJsF3t9j3X5ujDoNJvaByQCBaWMAAAgAEAAIAAAACAAgAAgAAAAAAAAAAAAAEBR1IhAmVKLptGnJ2/0hQFwseRORW4VaBsTznHZqb0ViUAnpfYIQMX3dCaOPONonaGjNXDElM6dR32ADPyNLYcsofLG4MLfVKuIgICZUoum0acnb/SFAXCx5E5FbhVoGxPOcdmpvRWJQCel9gckAgWljAAAIABAACAAAAAgAIAAIAAAAAADwAAACICAxfd0Jo4842idoaM1cMSUzp1HfYAM/I0thyyh8sbgwt9HKiQh5owAACAAQAAgAAAAIACAACAAAAAAA8AAAAA

At this point you can go to the Payments tab in Gordian Cosigner and import this PSBT, and then you'll be given the opportunity to sign it.

Finalizing PSBTs in Specter Desktop

Any networked wallet can send out the PSBT once everyone has signed it. In Specter Desktop you click Paste signed transaction and on success Specter will offer you to broadcast it.

Congratulations, you've finished the round-trip for a multisig PSBT, using Gordian Cosigner and Specter Desktop.