feat(abstract-utxo): add zec shielded psbt decode and recipient resolution support by veetragjain · Pull Request #9642 · BitGo/BitGoJS

veetragjain · 2026-09-03T07:50:09Z

linear-code · 2026-09-03T07:50:12Z

github-actions · 2026-09-03T08:00:09Z

⚠️ Unit tests are failing on Node 26.x (Current release line, non-blocking). This is not an LTS version yet, so it does not block merge, but it signals an incompatibility to fix before Node 26.x becomes LTS.

View run

OttoAllmendinger · 2026-09-07T10:50:11Z

+  /**
+   * Custom change wallet xpubs, when the transaction spends to a custom change wallet. Outputs
+   * matching these keys are classified as change, not recipients — matching how
+   * `explainPsbtWasm` treats them.
+   */
+  customChangeXpubs?: Triple<string>;


we don't need to support custom change wallets, let's leave this unimplemented and fail hard if a custom change wallet is configured

OttoAllmendinger · 2026-09-07T10:51:02Z

+  try {
+    return fixedScriptWallet.ZcashUnifiedAddress.parse(address, network);
+  } catch (e) {
+    return undefined;


we should prefer failing hard instead

Failing hard now

OttoAllmendinger · 2026-09-07T10:51:43Z

+    address: string,
+    param?: { anyFormat?: boolean; allowLightning?: boolean } | boolean
+  ): boolean {
+    const unifiedAddress = tryParseUnifiedAddress(address, this.name as 'zec' | 'tzec');


this seems to be the only site where we use the undefined returning func, I'd rather inline the catch here

catching the error now

OttoAllmendinger · 2026-09-07T10:53:10Z

+      // `ZcashBitGoPsbt.fromBytes` signals v6 (Ironwood) bytes with a plain Error (not a
+      // WasmUtxoError) telling the caller to use `ZcashIronwoodBitGoPsbt.fromBytes` instead —
+      // see its doc comment. Fall back for that message as well as wasm-layer errors.
+      if (isWasmUtxoError(e) || (e instanceof Error && e.message.includes('v6 (Ironwood)'))) {


This is a brittle way to identify errors. We have a more structured system for categorizing errors in wasm-utxo already, please check if we can already use it. If not, submit a change for wasm-utxo so we have a proper error code here instead and let's fix it in a follow-up.

Using the new ZcashBitGoPsbt.fromBytes which automatically detects the version and returns the right psbt instance

Ticket: CSHLD-1639

OttoAllmendinger · 2026-09-09T07:49:50Z

+import { resolvePsbtRecipients, PsbtRecipient } from './recipients';

 export class Zec extends AbstractUtxoCoin {
  readonly name: UtxoCoinName = 'zec';


Suggested change

readonly name: UtxoCoinName = 'zec';

readonly name: 'zec' | 'tzec' = 'zec';

this should get rid of the as 'zec' | 'tzec' casts, please try

OttoAllmendinger · 2026-09-09T07:50:01Z

+        // Raw script inherently transparent.
+        return 'transparent' as const;


OttoAllmendinger · 2026-09-09T07:52:06Z

+        // Not a unified address: the ordinary transparent address-decoding path handles it.
+        return 'transparent' as const;


I don't agree with that

ZcashUnifiedAddress.parse can fail for many different reasons, I don't think it's fair to assume transparent as a good default here

we should try to parse it as a transparent address first instead, return transparent on success, and then try to parse it as a Unified address and propagate the error if it is nothing recognizable

OttoAllmendinger · 2026-09-09T07:55:21Z

+   * only be spent shielded, one carrying only a transparent receiver only transparently, one
+   * carrying both is ambiguous, and a mix of shielded and transparent recipients is rejected.
+   */
+  getUnifiedRecipientPreference(txParams: {


I don't see any tests

move this to a standalone func to recipients.ts and add better tests for it

you can also clean up the signature

getUnifiedRecipientPreference( name: 'zec' | 'tzec', recipients: { address: string | undefined; }[] // amount isn't actually used )

OttoAllmendinger · 2026-09-09T07:56:02Z

+  /* Zcash-only: how to resolve a Unified Address recipient ('shielded' or transparent) */
+  unifiedRecipientPreference: t.string,


use a union of literals here

OttoAllmendinger · 2026-09-09T07:56:15Z

+   * Orchard/Ironwood receiver (a shielded output); any other value (or omission) resolves it to
+   * its transparent receiver.
+   */
+  unifiedRecipientPreference?: string;


use 'shielded' | 'transparent' here

OttoAllmendinger · 2026-09-09T07:58:08Z

+   * whose address space needs additional context to resolve — e.g. Zcash Unified Addresses,
+   * which resolve differently depending on `unifiedRecipientPreference`.
+   */
+  resolveOutputScript(address: string, unifiedRecipientPreference?: string): Uint8Array {


weak string type

the optional argument here is only useful for zcash and leaks into general AbstractUtxo, we should look for a better solution

OttoAllmendinger · 2026-09-09T08:07:26Z

+export function fromExtendedAddressFormatToScript(
+  extendedAddress: string,
+  coinName: UtxoCoinName,
+  resolveScript?: (address: string, coinName: UtxoCoinName) => Uint8Array


this looks a bit problematic, let's find a better solution here.

let's split up the PR and discuss these changes later

do a separate PR that adds

getUnifiedRecipientPreference( name: 'zec' | 'tzec', recipients: { address: string | undefined; }[] // amount isn't actually used )

only

as discussed here

https://github.com/BitGo/BitGoJS/pull/9642/changes#r3965967895

veetragjain force-pushed the veetragjain/cshld-1639-resolve-zec-unified-address-recipients-for-shielding branch 2 times, most recently from c0b5ca0 to d3a9a4f Compare September 4, 2026 19:50

veetragjain changed the title ~~feat(abstract-utxo): support shielding transaction build and decode~~ feat(abstract-utxo): add zec shielded psbt decode and recipient resolution support Sep 4, 2026

veetragjain marked this pull request as ready for review September 7, 2026 10:00

veetragjain requested review from a team as code owners September 7, 2026 10:00

veetragjain requested review from s84krish and vibhavgo September 7, 2026 10:00

OttoAllmendinger requested changes Sep 7, 2026

View reviewed changes

veetragjain force-pushed the veetragjain/cshld-1639-resolve-zec-unified-address-recipients-for-shielding branch from d3a9a4f to 14d690e Compare September 9, 2026 06:32

fix(abstract-utxo): add zec psbt decode and UA resolution support

70ffbd0

Ticket: CSHLD-1639

veetragjain force-pushed the veetragjain/cshld-1639-resolve-zec-unified-address-recipients-for-shielding branch from 14d690e to 70ffbd0 Compare September 9, 2026 07:22

veetragjain requested a review from OttoAllmendinger September 9, 2026 07:37

OttoAllmendinger requested changes Sep 9, 2026

View reviewed changes

	readonly name: UtxoCoinName = 'zec';
	readonly name: 'zec' \| 'tzec' = 'zec';

		// Raw script inherently transparent.
		return 'transparent' as const;

		// Not a unified address: the ordinary transparent address-decoding path handles it.
		return 'transparent' as const;

		/* Zcash-only: how to resolve a Unified Address recipient ('shielded' or transparent) */
		unifiedRecipientPreference: t.string,

Uh oh!

Conversation

veetragjain commented Sep 3, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

linear-code Bot commented Sep 3, 2026

Uh oh!

github-actions Bot commented Sep 3, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

veetragjain commented Sep 3, 2026 •

edited

Loading

github-actions Bot commented Sep 3, 2026 •

edited

Loading