aztec-wallet-sdk

name	aztec-wallet-sdk
description	Use this skill when integrating Aztec wallet connectivity with @aztec/wallet-sdk, including discovery/session flows, secure-channel key exchange, extension handlers, encrypted messaging, and BaseWallet implementations.
license	Proprietary. LICENSE.txt has complete terms
compatibility	Pinned to aztec-packages v4.2.0 (commit f8c89cf4345df6c4ca9e66ea9b738e96070abc5a).
metadata	{"version_label":"v4.2.0","commit_sha":"f8c89cf4345df6c4ca9e66ea9b738e96070abc5a","source_map":"aztec-packages/yarn-project/wallet-sdk"}

Aztec Wallet SDK Integration

Overview

Use this skill for wallet connectivity and wallet-provider implementation work with @aztec/wallet-sdk.

Primary scope:

• dApp wallet discovery with WalletManager
• secure channel establishment (PendingConnection, key exchange, verification hash)
• extension-specific provider usage (ExtensionProvider, ExtensionWallet)
• extension relay handlers (BackgroundConnectionHandler, ContentScriptConnectionHandler)
• encrypted message protocol and session lifecycle handling
• wallet implementation extension via BaseWallet

Out of scope:

• Noir/Aztec.nr contract authoring (use aztec-contracts)
• contract deployment workflows (use aztec-deployment)
• broad Aztec.js app development beyond wallet-connection concerns (use aztec-js)

Required Repository State

Use the upstream repository and pin:

• Repo: https://github.com/AztecProtocol/aztec-packages
• Tag: v4.2.0
• Commit: f8c89cf4345df6c4ca9e66ea9b738e96070abc5a
• Source root: yarn-project/wallet-sdk

Checkout example:

git clone https://github.com/AztecProtocol/aztec-packages.git
cd aztec-packages
git checkout v4.2.0
git status

Expected status includes HEAD detached at v4.2.0.

Operating Rules

• Follow the two-phase protocol strictly: discovery first, then key exchange.
• Do not call wallet methods until PendingConnection.confirm() succeeds.
• Treat verification-hash comparison as mandatory before confirming a connection.
• Keep extension private keys and derived session keys in background context only.
• Keep content scripts as message relays only; no crypto or session-key state there.
• Handle disconnect control messages (WalletMessageType.DISCONNECT) and cleanup all in-flight requests.
• Use explicit chainInfo and appId on discovery and message flows.
• Respect allow/block list policies when exposing extension wallets.
• For custom wallet implementations, extend BaseWallet and implement account lookup and capability behavior explicitly.

Quick Start

# Install core SDK deps (choose one package manager)
scripts/install_wallet_sdk_deps.sh npm

import { Fr } from '@aztec/aztec.js/fields';
import { WalletManager } from '@aztec/wallet-sdk/manager';
import { hashToEmoji } from '@aztec/wallet-sdk/crypto';

const discovery = WalletManager.configure({
  extensions: { enabled: true },
}).getAvailableWallets({
  chainInfo: { chainId: new Fr(31337), version: new Fr(1) },
  appId: 'my-dapp',
  timeout: 60000,
});

for await (const provider of discovery.wallets) {
  const pending = await provider.establishSecureChannel('my-dapp');
  console.log('Verify:', hashToEmoji(pending.verificationHash));
  const wallet = await pending.confirm();
  const accounts = await wallet.getAccounts();
  .(accounts);
}

Core Workflows

1. Discover Wallet Providers (dApp Side)

• Configure manager with WalletManager.configure({ extensions: { enabled: true } }).
• Start discovery with getAvailableWallets({ chainInfo, appId, timeout, onWalletDiscovered? }).
• Consume discovered providers using either:
• async iteration via discovery.wallets
• callback via onWalletDiscovered
• Cancel discovery on route/network changes via discovery.cancel().

2. Establish and Verify Secure Channel

• Call provider.establishSecureChannel(appId).
• Display pending.verificationHash using hashToEmoji(...).
• Require user confirmation that wallet UI and dApp UI match.
• Call pending.confirm() only after user confirmation.
• Call pending.cancel() if verification fails.

3. Use Low-Level Extension Provider (When Needed)

• Use ExtensionProvider.discoverWallets(chainInfo, options) when bypassing manager abstractions.
• Handle DiscoveredWallet entries through onWalletDiscovered callback.
• Promote a discovered wallet to connected state with discovered.establishSecureChannel().
• Enforce key exchange timeout handling and retry policy.

4. Implement Extension Wallet Transport

Background script:

• Instantiate BackgroundConnectionHandler(config, transport, callbacks).
• Call initialize() once.
• All BackgroundConnectionCallbacks fields are optional:
  • onPendingDiscovery — queues approval UI for incoming discovery requests.
  • onSessionEstablished — notified when key exchange completes and a session is live.
  • onSessionTerminated — notified when a session ends (disconnect or tab close).
  • onWalletMessage — receives decrypted wallet calls; call sendResponse with result.
• On user approval/rejection, call approveDiscovery(requestId) or rejectDiscovery(requestId).
• Forward decrypted wallet calls from onWalletMessage to wallet backend.
• Return encrypted responses through sendResponse(sessionId, walletResponse).
• Declare handler with let before defining callbacks that reference it (avoids temporal deadzone).

Content script:

• Instantiate ContentScriptConnectionHandler(transport).
• Call start() once.
• Relay discovery, key exchange, encrypted messages, and disconnect notifications.

5. Encrypted Protocol and Message Types

• Discovery/control types use WalletMessageType:
• DISCOVERY
• DISCOVERY_RESPONSE
• KEY_EXCHANGE_REQUEST
• KEY_EXCHANGE_RESPONSE
• DISCONNECT
• Use generateKeyPair, exportPublicKey, importPublicKey, deriveSessionKeys for key exchange.
• Use encrypt/decrypt for all post-handshake payloads.
• Keep request correlation by requestId/messageId and validate walletId on responses.

6. Build Custom Wallets with BaseWallet

• Extend BaseWallet for wallet implementations backed by PXE + Aztec node.
• Implement:
• getAccountFromAddress(address)
• getAccounts()
• Use built-ins for common wallet operations:
• simulateTx, profileTx, sendTx
• registerContract, registerSender
• createAuthWit, getPrivateEvents
• getContractMetadata, getContractClassMetadata
• Override capabilities handling with requestCapabilities(...) for external wallets.
• BaseWallet.sendTx returns { receipt?, txHash?, offchainEffects, offchainMessages }. Custom Wallet / BaseWallet implementations must call extractOffchainOutput(provenTx.getOffchainEffects(), provenTx.publicInputs.constants.anchorBlockHeader.globalVariables.timestamp) (the anchor-block timestamp argument is mandatory in v4.2.0) and spread the result into the returned object — the OffchainMessage.anchorBlockTimestamp field added in this release is set from that argument.

7. Session Lifecycle and Disconnect Handling

• Register disconnect hooks via provider.onDisconnect(callback) — returns an unsubscribe function.
• Check provider.isDisconnected() to test current session state without polling.
• On disconnect, clear app state and stop using prior wallet handles.
• Call provider.disconnect() on app shutdown or wallet switch.
• In background handler, terminate stale sessions with terminateSession(...)/terminateForTab(...)/clearAll().

8. Test and Validation Flow

• Use wallet-sdk unit tests in yarn-project/wallet-sdk/src/**/*.test.ts as behavior references.
• Validate mixed simulation path behavior and private-event decoding patterns from base_wallet.test.ts.
• Add integration checks for:
• discovery timeout behavior
• key exchange timeout (2s in DiscoveredWallet)
• disconnect propagation and in-flight rejection handling

Tooling / Commands

# preflight checks (node + package manager + optional node URL + optional source path)
scripts/preflight_wallet_sdk.sh [node-url] [wallet-sdk-dir]

# install wallet-sdk dependencies
scripts/install_wallet_sdk_deps.sh <npm|yarn|pnpm> [version]

# run a TS wallet-sdk example with tsx (tsx must be installed: npm install -D tsx)
scripts/run_wallet_sdk_example.sh <entry-file.ts> [-- <extra-args...>]

# summarize package entrypoints/exports from aztec-packages checkout
scripts/summarize_wallet_sdk_exports.sh <aztec-packages-dir>

# run wallet-sdk package tests from aztec-packages checkout
scripts/run_wallet_sdk_tests.sh <aztec-packages-dir> [test-name-pattern]

Edge Cases and Failure Handling

• Wallet discovery yields no providers: check user approval path and discovery timeout (default 60000ms).
• Key exchange fails with timeout: DiscoveredWallet.establishSecureChannel() enforces a 2000ms timeout; retry from approved discovery state.
• Verification hash mismatch: cancel the pending connection and do not call confirm().
• Wallet responses ignored unexpectedly: validate walletId, messageId, and per-session routing state.
• Calls fail after disconnect: expected; ExtensionWallet rejects in-flight and future calls once disconnected.
• Extension appears in discovery but not manager output: check allowList/blockList filtering in manager config.
• PendingDiscovery.appName is always undefined at this pin: DiscoveryRequest does not carry an appName field, so BackgroundConnectionHandler never populates it. Do not rely on it for UI labelling; use appId and origin instead.

Next Steps / Related Files

• Use reference.md for pinned source corpus and API/file map.
• Use patterns.md for reusable dApp and extension integration snippets.
• Use scripts/ for repeatable setup, inspection, and test workflows.