Descriptor export from Sparrow and Specter (desktop)

Pick the Sparrow Wallet or Specter Desktop export the SeedHammer II reads, move it from the computer to a phone, and send it to the machine.

Sparrow 2.5.5 and Specter Desktop 2.1.11 hold the descriptor of every wallet they coordinate, including multisig wallets whose signers have no NFC. The exports below reach the SH II (stock firmware v1.4.3) through a phone running NFC Tools.

Seed words are typed on the machine only and never pass through a phone, a computer or a chat assistant. A descriptor is not a secret, but it reveals every address of the wallet.

What you need

The SH II on stock firmware v1.4.3, showing "Backup Wallet", and a phone with NFC Tools (write steps).
Sparrow 2.5.5 or Specter Desktop 2.1.11 with the wallet open: single-sig, or a sorted multisig (sortedmulti) as P2WSH, P2SH-P2WSH or P2SH (scripts).

Export from Sparrow

Open the wallet and click Settings in the left column.
Right-click the Descriptor: field.
Click Copy Output Descriptor. The text goes to the clipboard; no dialog opens.

Remove `?bh=` or `?gl=`

Sparrow 2.5 and later write a BIP393 annotation before the #: ?bh=<height> once the wallet has a confirmed payment, ?gl=<limit> once the gap limit was changed under Advanced.... In a plain-text editor on the computer, delete from ? to the end of a one-line descriptor, checksum included; the machine engraves its own. Never retype a key character.
In Sparrow's Specter Desktop file, delete from ? up to the closing " of the descriptor, and keep that " and the }.

Export a multisig setup file

Click Export... at the bottom left of Settings.
In the Coldcard Multisig pane, click Export File.... Keystone Multisig, Passport Multisig and BlueWallet Vault Multisig write the same text.
Click Save. The file is <wallet name>-coldcard.txt, for example Demo 2of3-coldcard.txt.

Sparrow export dialog: BSMS, BlueWallet Vault Multisig, Coldcard Multisig and Electrum panes with Show... and Export File...

Sparrow export	"Title" on the machine	Machine reads it	Child path on the plate
Copy Output Descriptor	none	yes, once `?bh=` or `?gl=` is removed	`/<0;1>/*`, receive and change
Coldcard Multisig file	wallet name	yes, if all cosigners share one derivation path	none; a Coldcard refuses the plate on import

Export from Specter Desktop

Click the wallet under Wallets in the sidebar.
Click the wallet's Settings tab, beside Send.
Click Export.
Click Go to export details. The dialog "Export Wallet" opens.
Click Save Wallet File. Specter saves <wallet name>.json, for example Demo 2of3.json.
Or click into the Wallet JSON Data box, select all and copy. Copy Wallet Data copies nothing.

Specter Desktop Export Wallet dialog: QR code, Wallet JSON Data, Copy Wallet Data and Save Wallet File

Specter export	"Title" on the machine	Machine reads it	Child path on the plate
Save Wallet File or Wallet JSON Data	wallet name	yes	`/0/*`, receive only (change addresses)
Download Specter JSON file, also named `Demo 2of3.json`	none	no, "Unknown format"	none

Move the text to the phone

Mac and iPhone: copy on the Mac, paste in NFC Tools (Universal Clipboard: same Apple Account, Bluetooth, Wi-Fi and Handoff on).
File: send the .txt or .json to the phone (AirDrop, or a USB cable to Android), open it, select all and copy.
QR code: read Sparrow's Specter Desktop or BlueWallet Vault Multisig code (Show...), or Specter's "Export Wallet" code before you click it, with the phone camera (unverified). Other codes in both apps are UR, BBQr or text the machine refuses. Never use Live Text on the screen: Coldcard-format text has no checksum.
Write the text as one Text record (NFC Tools); setup text keeps its inner line breaks. "Engrave Descriptor" shows the "Title" of a titled export, and the title is not engraved.

If it does not work

Symptom	Cause	Fix
"Unknown format", Sparrow text holds `?bh=` or `?gl=`	BIP393 annotation, written after a confirmed payment or a gap-limit change	Delete it as above. A QR code carries it too: take the file.
"Unknown format", one-line descriptor	A line break or space after the text	Delete it. A setup file may end in one line break.
"Unknown format", Sparrow Output Descriptor file	The whole file: three descriptors and comment lines	Send only the line under `# Receive and change descriptor:`, without its line break, or use Copy Output Descriptor.
"Unknown format", text like `wsh(sortedmulti(2,DemoA,DemoB,DemoC))`	Copy Value copies the policy with keystore names	Click Copy Output Descriptor in the same menu.
"Singlesig" "Legacy (P2PKH)" for a segwit wallet	Copy xpub on a keystore: a bare key with no fingerprint or path	Use Copy Output Descriptor (bare keys).
Nothing to paste after Specter's Copy Wallet Data	The button copies nothing, although "Copied wallet data" appears	Click Save Wallet File, or select all in Wallet JSON Data and copy.
Checksum differs between exports, or from the plate	Key order: Copy Output Descriptor sorts the keys, the Specter Desktop file keeps keystore order; the checksum covers every character	Compare the first receive address (why).