Brave x Polkadot Wallet Integration Proposal

Updated: 2/20/25

Summary of Changes Made

• Clarified Smoldot integration, SCALE codec, and Substrate transaction handling in the milestones.
• Expanded User Interface and Experience section to highlight how Polkadot and Kusama will be integrated into Brave Wallet.
• Emphasized Brave’s C++ security model, including process isolation for vulnerable components.
• Strengthened investment justification by detailing why Brave must port JavaScript-based functionalities into C++.
• Updated open-source commitment to confirm that Brave will release all Polkadot-related code.
• Added Brave’s $100K ad credit to Polkadot upon proposal approval.

Executive Summary

This proposal outlines the native integration of Polkadot functionality into Brave’s self-custody wallet, granting Brave’s 80M+ monthly active users direct access to the Polkadot and Kusama ecosystems. This integration will be implemented natively in Brave’s core C++ architecture over 12 months, ensuring maximum security, privacy, and performance, while also committing to a 24-month maintenance period for ongoing updates and optimizations.

Market Opportunity & Impact

Brave's extensive user base provides a significant opportunity for Polkadot adoption:

• 80M monthly active users
• 34.71M daily active users
• 20.8M potential developers (25% of the user base)
• Strong crypto adoption (60% involved in staking, 20% own NFTs)

By integrating Polkadot natively, Brave Wallet will streamline user access to Web3, facilitating secure XCM-based cross-chain transfers, governance participation, and direct dApp interactions.

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Value Proposition & Investment Request

• Total Investment: $3,000,000 USDC
• Development Timeline: 12 months
• Maintenance Period: 24 months
• Total Commitment: 36 months

Development Milestones & Deliverables

Milestone 1: Research & Polkadot HD Keyring

• Polkadot BraveWallet integration UX research.
• Polkadot HD Keyring support.
• Polkadot\Kusama account creation, ss58 address space support.
• BraveWallet architecture adoption to support parachain network layer abstraction.
• Security audit.

Milestone 2: Relay chains support

• Smoldot integration\implementation over Chromium network stack. Own implementation may be required.
• SCALE codec integration\implementation. Own implementation may be required.
• Substrate transaction creation and signing implementation.
• Balance pallet integration.
• Relay chain native tokens support: balance resolution, transaction creation, fee calculation, recipient validation, transaction signing&posting flow, transaction status subscription, blockexplorer integration.
• Security audit.
• QA.

Milestone 3: Network & Parachains support

• Parachains metadata fetching, parsing and compatibility verification.
• Substrate Parachains integration into the wallet flow(top 5-10 parachains): supported parachains list, account details page, settings, portfolio, send screen, transaction details, recipient list integration.
• Most used pallets support - assets, balances, nfts.
• Security audit.
• QA.

Milestone 4: Assets support

• EVM based parachains integration based on existing BraveWallet codebase.
• Cross-chain tokens support - cross-chain transactions.
• Implement native support of bridges between Brave Wallet supported blockchains and Polkadot.
• Security audit.
• QA.

Milestone 5: Ecosystem Integration & Deployment

• dApps connection support using native C++ implementation of window.polkadot.
• Ledger support - import account, sign transactions.
• Security audit.
• QA.

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Technical Architecture Overview

Core Implementation Strategy

• Native C++ integration in Brave’s core (No JavaScript dependencies)
• Custom Polkadot HD Keyring implementation.
• Custom transaction creation and signing component.
• Dynamic metadata retrieval to support Polkadot’s runtime upgrade model
• Smoldot-based RPC connectivity over Chromium network stack for decentralized network access
• Process isolation for potential vulnerable parts of code

Polkadot-Specific Integration

• EVM and Substrate based parachains integration.
• Support for Polkadot and Kusama parachain assets & XCM transactions
• Automated runtime metadata updates for compatibility with evolving networks
• Secure window.polkadot provider in C++ for efficient dApp connectivity

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User Interface and Experience

The screenshots below illustrate the current state of Brave Wallet’s account creation, hardware wallet import, and network selection interfaces. These images provide insight into how Polkadot will be incorporated into Brave Wallet’s multi-chain experience.

1. Account Creation & Import: Users can create and manage accounts for various blockchains, including Ethereum, Solana, Bitcoin, and Filecoin. With this integration, Polkadot and Kusama will be added to this interface, allowing users to create and manage DOT and KSM accounts directly within Brave Wallet.
2. Hardware Wallet Support: Brave Wallet enables users to connect hardware wallets to manage their crypto securely. Polkadot Ledger support will be introduced, allowing users to store and transact with DOT and parachain assets securely.
3. Network Selection: Users currently choose from a variety of networks, such as Ethereum, Solana, and Bitcoin. Polkadot and Kusama will be integrated as primary networks, ensuring that users can interact with the Polkadot ecosystem natively without needing external extensions.

Where Polkadot Will Be Featured

• Polkadot and Kusama will be available in the “Create Account” and “Import from Hardware Wallet” sections of Brave Wallet.
• DOT and KSM will be added to the “Select Networks” menu, allowing users to toggle between multiple blockchain ecosystems.
• XCM-based cross-chain functionality will be incorporated, enabling users to move assets between Polkadot parachains directly through Brave Wallet.
• Polkadot governance and staking will be integrated, allowing users to participate in Polkadot’s decentralized governance directly from Brave.

These updates ensure that Brave Wallet becomes a true multi-chain platform, where Polkadot users can interact with the ecosystem.

Success Metrics & Justification for $3M Investment

Technical KPIs

• 99.9% wallet uptime
• <3 second transaction processing
• Zero critical security incidents
• 100% parachain compatibility
• Cross-chain transaction success rate exceeding 99%

Investment Justification

• Brave’s security model requires all network interactions, signing, and chain logic to be implemented in C++ instead of JavaScript-based solutions.
• Comprehensive security reviews and dependency audits increase development costs.
• Brave must port key functionalities from JavaScript libraries into C++ to meet privacy and security requirements.
• The code must be integrated into the Chromium and Brave Wallet codebases, considering their limitations and established patterns.
• A long-term commitment (24 months of maintenance) ensures continuous support, updates, and ecosystem stability.

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Open Source & Long-Term Commitment

• Brave will open-source all code related to the Polkadot integration.
• 24-month maintenance commitment includes security patches, feature updates, and long-term support.
• Brave Ads will be leveraged to drive awareness and adoption of Polkadot’s integration. Upon approval of this proposal, Brave wll grant a $100k ad credit to Polkadot and its ecosystem.

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Conclusion

This integration represents a significant milestone for Polkadot adoption, onboarding millions of new users through Brave's privacy-first, security-focused browser environment. By implementing a fully native, high-performance C++ integration, Brave Wallet will serve as a gateway to Web3, enabling cross-parachain transactions, and dApp interactions—all without requiring third-party extensions. Brave Wallet supports multiple blockchains, including ETH, BTC, SOL, ZEC, and FIL, enabling seamless native cross-integration with the Polkadot ecosystem.

This proposal ensures long-term ecosystem growth, open-source contributions, and measurable adoption metrics, making it a strategic win for both Brave and Polkadot.

About us

Brave is a privacy-focused browser and search engine committed to empowering users with control over their online data and experiences. Our integrated Brave Wallet provides a seamless way to access Web3 with support for Ethereum, EVM chains, Solana, Bitcoin, and NFTs - no extensions required. Brave Rewards, our privacy-preserving ad platform, has the most crypto-centric audience available today.

Founded by JavaScript creator Brendan Eich, Brave is an open-source project fostering innovation through transparency and collaboration. The key team members involved in this proposal are:

• Carlos Acevedo —  Senior Director, Business Development — X, LinkedIn
• James Mudgett — VP, iOS, Web 3 — X, LinkedIn
• Oleg Isupov — Brave Wallet — X, LinkedIn
• Luke Mulks —  VP, Business Operations — X, LinkedIn
• Angelina Kraminkina —  Senior Client Success Manager, Enterprise — X, LinkedIn

Major brands across industries have trusted our advertising platforms, including Verizon, Ford, Lufthansa, Crocs, Venom, Mayfair, eToro, Crypto.com, Solana, Upland, Near, and Nexo.

With privacy at its core, Brave aims to improve the way we interact with both Web 2.0 and Web3.