✨ (signer-polkadot) [LIVE-30994]: Scaffold signer kit for Polkadot (Substrate chains)

[cted-ledger]

📝 Description

Scaffolds the @ledgerhq/device-signer-kit-polkadot package in packages/signer/signer-polkadot/.

This signer serves all Substrate chains (Polkadot, Bittensor, etc.) via configurable SS58 prefix and derivation path — following the pattern of signer-cosmos for non-EVM chains. Implements GetAddressCommand (SS58 prefix param) and SignTransactionCommand (SCALE payload + metadata blob).

❓ Context

• JIRA or GitHub link: LIVE-30994

✅ Checklist

• Covered by automatic tests
• Changeset is provided
• Documentation is up-to-date
• Impact of the changes:
  • New package signer-polkadot. No changes to existing signers or packages.
  • Unblocks LIVE-30995 (APDU implementation) and LIVE-30996 (live-signer wrapper in ledger-live).

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Project	Deployment	Actions	Updated (UTC)
device-sdk-ts-sample	Ready	Preview, Comment	May 20, 2026 11:27pm

1 Skipped Deployment

Project	Deployment	Actions	Updated (UTC)
doc-device-management-kit	Ignored		May 20, 2026 11:27pm

[Copilot]

Pull request overview

This PR scaffolds a new @ledgerhq/device-signer-kit-polkadot package (following the existing non‑EVM signer patterns) and wires it into the monorepo tooling, sample app, and documentation so it can be iterated on for upcoming APDU/protocol work.

Changes:

• Added the new Polkadot signer package skeleton (DI container, app binder, commands/tasks, API surface, build/lint/test configs).
• Integrated the signer into the sample app (provider, view, route, and signer list entry).
• Added Polkadot signer documentation and release/repo plumbing (docs nav, release aliases, changeset, lockfile/workspace entries).

Reviewed changes

Copilot reviewed 49 out of 50 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
pnpm-lock.yaml	Adds workspace entry/deps for the new signer package.
package.json	Adds a root script alias for signer-polkadot.
packages/signer/signer-polkadot/vitest.setup.mjs	Vitest setup (reflect-metadata).
packages/signer/signer-polkadot/vitest.config.mjs	Vitest configuration + coverage/aliases.
packages/signer/signer-polkadot/tsconfig.prod.json	Production TS config wrapper.
packages/signer/signer-polkadot/tsconfig.json	Package TS config (paths/types/output).
packages/signer/signer-polkadot/src/internal/use-cases/transaction/SignTransactionUseCase.ts	Use-case wrapper for sign-transaction device action.
packages/signer/signer-polkadot/src/internal/use-cases/transaction/di/transactionTypes.ts	DI symbols for transaction use-cases.
packages/signer/signer-polkadot/src/internal/use-cases/transaction/di/transactionModule.ts	DI bindings for transaction use-cases.
packages/signer/signer-polkadot/src/internal/use-cases/address/GetAddressUseCase.ts	Use-case wrapper for get-address device action.
packages/signer/signer-polkadot/src/internal/use-cases/address/di/addressTypes.ts	DI symbols for address use-cases.
packages/signer/signer-polkadot/src/internal/use-cases/address/di/addressModule.ts	DI bindings for address use-cases.
packages/signer/signer-polkadot/src/internal/externalTypes.ts	DI symbols for externally-provided instances (DMK/session).
packages/signer/signer-polkadot/src/internal/di.ts	Builds and loads the inversify container.
packages/signer/signer-polkadot/src/internal/DefaultSignerPolkadot.ts	Concrete SignerPolkadot implementation delegating to use-cases.
packages/signer/signer-polkadot/src/internal/app-binder/task/SignTransactionTask.ts	Task wrapper around the sign-transaction command.
packages/signer/signer-polkadot/src/internal/app-binder/PolkadotAppBinder.ts	DMK device-action wiring for getAddress/signTransaction.
packages/signer/signer-polkadot/src/internal/app-binder/di/appBinderTypes.ts	DI symbols for the app binder.
packages/signer/signer-polkadot/src/internal/app-binder/di/appBinderModule.ts	DI bindings for the app binder.
packages/signer/signer-polkadot/src/internal/app-binder/constants.ts	Polkadot app constants (name/CLA/INS).
packages/signer/signer-polkadot/src/internal/app-binder/command/utils/polkadotApplicationErrors.ts	Placeholder error-code enum for Polkadot app.
packages/signer/signer-polkadot/src/internal/app-binder/command/SignTransactionCommand.ts	Sign-transaction command scaffold (APDU + parse TBD).
packages/signer/signer-polkadot/src/internal/app-binder/command/GetAddressCommand.ts	Get-address command scaffold (APDU + parse TBD).
packages/signer/signer-polkadot/src/index.ts	Package entrypoint exporting API.
packages/signer/signer-polkadot/src/api/SignerPolkadotBuilder.ts	Public builder to construct the signer.
packages/signer/signer-polkadot/src/api/SignerPolkadotBuilder.test.ts	Minimal builder/constants tests.
packages/signer/signer-polkadot/src/api/SignerPolkadot.ts	Public signer interface (getAddress/signTransaction).
packages/signer/signer-polkadot/src/api/model/TransactionOptions.ts	Transaction options type.
packages/signer/signer-polkadot/src/api/model/Signature.ts	Signature type definition.
packages/signer/signer-polkadot/src/api/model/AddressOptions.ts	Address options type.
packages/signer/signer-polkadot/src/api/index.ts	API barrel exports.
packages/signer/signer-polkadot/src/api/app-binder/SignTransactionDeviceActionTypes.ts	Public DA types for signing.
packages/signer/signer-polkadot/src/api/app-binder/GetAddressDeviceActionTypes.ts	Public DA types for getAddress.
packages/signer/signer-polkadot/README.md	Package README (usage/install/dev).
packages/signer/signer-polkadot/package.json	New package manifest (exports/scripts/deps).
packages/signer/signer-polkadot/eslint.config.mjs	Package eslint configuration.
packages/signer/signer-polkadot/CHANGELOG.md	Initial changelog entry.
packages/signer/signer-polkadot/.prettierrc.js	Prettier config wiring.
packages/signer/signer-polkadot/.prettierignore	Prettier ignore list.
apps/sample/src/providers/SignerPolkadotProvider/index.tsx	Adds signer provider to sample app.
apps/sample/src/components/SignerView/index.tsx	Adds Polkadot entry to supported signers list.
apps/sample/src/components/SignerPolkadotView/index.tsx	Adds Polkadot device-action tester view.
apps/sample/src/app/signers/polkadot/page.tsx	Adds Polkadot signer page route.
apps/sample/src/app/client-layout.tsx	Registers the Polkadot signer provider in layout.
apps/sample/package.json	Adds dependency on the new signer package.
apps/docs/pages/docs/references/signers/polkadot.mdx	Adds Polkadot signer documentation page.
apps/docs/pages/docs/references/signers/_meta.js	Adds Polkadot entry to docs sidebar meta.
.cursor/skills/release/SKILL.md	Adds release alias mapping for signer-polkadot.
.cursor/scripts/release/config.cjs	Adds release alias + display name for the new package.
.changeset/yummy-news-bow.md	Adds changeset for initial Polkadot signer release.

Files not reviewed (1)

• pnpm-lock.yaml: Language not supported

Comments suppressed due to low confidence (4)

packages/signer/signer-polkadot/README.md:25

• SignerPolkadot.signTransaction requires both blob and metadata (plus optional options), but the README example only passes transactionBytes. Update the example to include the metadata parameter (or explicitly pass an empty metadata blob if that’s the intended placeholder).

// Sign transaction
const signature = await signer.signTransaction(
  "m/44'/0'/0'/0/0",
  transactionBytes,
);

apps/docs/pages/docs/references/signers/polkadot.mdx:142

• The docs describe signTransaction(derivationPath, transaction, options) and show a {r,s,v} signature shape, but the exported API is signTransaction(derivationPath, blob: Uint8Array, metadata: Uint8Array, options?) and Signature is a Uint8Array. Please align the docs (parameters + return type example) with the actual types.

```typescript
const { observable, cancel } = signerPolkadot.signTransaction(
  derivationPath,
  transaction,
  options,
);

Parameters

• derivationPath

  • Required
  • Type: string (e.g., "m/44'/0'/0'/0/0")
  • The derivation path used for the polkadot transaction. See here for more information.

• transaction

  • Required
  • Type: Uint8Array
  • The serialized transaction to be signed.

• options

  • Optional

  • Type: TransactionOptions

    type TransactionOptions = {
      skipOpenApp?: boolean;
    };

  • skipOpenApp: An optional boolean indicating whether to skip opening the polkadot app automatically (true) or not (false).

Returns

• observable Emits DeviceActionState updates, including the following details:

type Signature = {
  r: string;
  s: string;
  v?: number;
};

**apps/sample/src/components/SignerPolkadotView/index.tsx:77**
* The transaction hex parsing here will silently produce incorrect bytes for invalid input (e.g. non-hex chars -> `NaN` -> coerces to `0`, odd-length strings, etc.). The sample app already uses `hexaStringToBuffer` in other signer views (e.g. Zcash); consider using it here and throwing on invalid hex to avoid testing against malformed payloads.

      // Convert hex string to Uint8Array
      const txBytes = transaction.startsWith("0x")
        ? new Uint8Array(
            transaction
              .slice(2)
              .match(/.{1,2}/g)
              ?.map((byte) => parseInt(byte, 16)) ?? []
          )
        : new Uint8Array(
            transaction
              .match(/.{1,2}/g)
              ?.map((byte) => parseInt(byte, 16)) ?? []
          );

**apps/sample/src/components/SignerPolkadotView/index.tsx:80**
* This call does not match the `SignerPolkadot.signTransaction` signature. The API is `(derivationPath, blob: Uint8Array, metadata: Uint8Array, options?)`, but the sample passes `(derivationPath, ss58Prefix, txBytes, options)`. Update the UI/handler to provide `metadata` and pass parameters in the correct order/types.

      return signer.signTransaction(derivationPath, Number(ss58Prefix), txBytes, {
        skipOpenApp,
      });

</details>



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