How to Architect a Layer 1 Agnostic Wallet Solution

A layer 1 agnostic wallet is a single user interface that can manage assets and execute transactions across multiple, independent blockchains like Ethereum, Solana, and Bitcoin. The core architectural challenge is abstracting away the unique complexities of each chain—different signature schemes, transaction formats, and RPC methods—behind a unified API. This is distinct from multi-chain wallets that simply bundle separate chain-specific modules; an agnostic architecture uses a common abstraction layer, allowing new chains to be integrated by implementing a standardized adapter interface.

The foundation of this architecture is a wallet core or provider abstraction layer. This component exposes a consistent set of methods—such as getBalance, signTransaction, and sendTransaction—to the frontend. Internally, it routes requests to the appropriate chain adapter. For example, when a user wants to send USDC on Arbitrum, the core identifies the correct EVM adapter, which then handles constructing a EIP-1559 transaction, signing it with the user's key, and broadcasting it via an Arbitrum RPC endpoint. Popular libraries like WalletConnect's Web3Modal or Ethers.js AbstractProvider` exemplify this pattern.

Key considerations for the adapter layer include key management and signature abstraction. A wallet might use a single hierarchical deterministic (HD) key derived from a seed phrase, but different chains require different derivation paths and signature algorithms (e.g., secp256k1 for EVM, Ed25519 for Solana). The architecture must securely manage these keys and normalize signing operations. Furthermore, state and nonce management must be handled per chain, as tracking a pending transaction on Solana is fundamentally different from tracking one on Ethereum.

For developers, implementing a new chain adapter involves three main steps. First, create a class that implements your core ChainAdapter interface. Second, integrate the chain's native SDK (like @solana/web3.js or bitcoinjs-lib) to handle transaction construction and signing. Third, implement network-specific utilities for gas estimation, fee calculation, and blockchain interaction. Testing is critical; use testnets for all supported chains and simulate complex cross-chain scenarios like insufficient gas on one network affecting the unified UI state.

The primary benefit of this architecture is developer and user experience. Applications can integrate one wallet SDK instead of many, and users have a single recovery phrase for all their assets. However, it introduces complexity in security auditing and increases the attack surface. Always use reputable, audited libraries for cryptographic operations and consider implementing features like transaction simulation (using services like Tenderly or Solana's simulation) before signing to protect users from unintended outcomes across any connected chain.

The primary prerequisite is a deep understanding of elliptic curve cryptography (ECC) and public-key infrastructure (PKI). Your wallet's core function is to generate, store, and use cryptographic key pairs. You must implement or integrate a library for the secp256k1 curve, which is used by Bitcoin, Ethereum, and most EVM-compatible chains. For chains like Solana (Ed25519) or Cardano (Ed25519-BIP32), you'll need support for additional curves. A foundational dependency here is a battle-tested library like @noble/curves in JavaScript or libsecp256k1 in Rust, which provide the mathematical primitives for secure key generation and signing.

Next, you need a modular provider architecture. Instead of hardcoding to a single chain's RPC endpoints, your wallet should abstract chain interaction behind a provider interface. Define a core Provider interface with methods like getBalance, sendTransaction, and estimateGas. Then, implement concrete providers: an EVMProvider for Ethereum and its L2s, a SolanaProvider using @solana/web3.js, and a CosmosProvider leveraging @cosmjs. This pattern, similar to libraries like ethers.js' AbstractProvider, allows you to support new chains by adding a provider module without altering the wallet's core logic.

Transaction construction and signing must be chain-agnostic. This requires a dependency on Transaction Builders and Serialization libraries specific to each ecosystem. For EVM chains, you'll use ethers.js or viem to populate and serialize EIP-1559 transactions. For Solana, you use @solana/web3.js to build VersionedTransaction objects. For UTXO-based chains like Bitcoin, you need a library like bitcoinjs-lib. Your wallet's job is to unify these behind a standard internal representation (e.g., a raw payload and a signature) before broadcasting via the appropriate provider.

State and account management is critical. You will need a secure, isolated key management system. Dependencies like @metamask/eth-sig-util or the Web Crypto API can handle encryption and decryption of private keys or seed phrases. Your architecture should treat the Hierarchical Deterministic (HD) wallet path (defined in BIP-32, BIP-44, BIP-39) as the source of truth. From a single seed, you can derive keys for different chains by following standard derivation paths (e.g., m/44'/60'/0'/0/0 for Ethereum, m/44'/501'/0'/0' for Solana). This ensures a unified account experience across blockchains.

Finally, you must integrate network and fee estimation services. Users need to see accurate gas fees on Ethereum, priority fees on Solana, and compute unit prices on Sui. This requires each provider module to implement a getFeeEstimates method, often polling chain-specific RPC methods or external APIs like Gas Station Network (GSN) for EVM chains or Solana's getRecentPrioritizationFees. The wallet UI then presents this complex data in a simplified, consistent format, abstracting the underlying chain's idiosyncrasies from the end-user.

The foundation of a Layer 1 agnostic wallet is a clear separation between the wallet core and chain-specific adapters. The core manages universal state—like user identity, private key storage, and transaction queuing—while adapters handle the unique logic for each blockchain. For example, signing a transaction on Ethereum requires an EIP-1559 fee market calculation, while Solana uses a recent blockhash and fee payer model. This adapter pattern, similar to the Chain Abstraction movement's goals, ensures adding support for a new chain doesn't require rewriting the entire application.

A robust account abstraction layer is critical for managing diverse account models. Your architecture must support Externally Owned Accounts (EOAs) for EVM chains, program-derived accounts for Solana, and potentially smart contract wallets like Safe (formerly Gnosis Safe) or ERC-4337 account factories. This layer provides a unified interface (signTransaction, getBalance, sendTransaction) that the wallet UI calls, delegating the chain-specific implementation to the corresponding adapter. This abstraction is what allows a single 'Send' button to work for ETH on Arbitrum, SOL on Solana, and USDC on Polygon.

For state and data synchronization, implement a multi-chain RPC (Remote Procedure Call) manager. This component should handle connection pooling, fallback providers for reliability, and real-time subscription to blockchain events (new blocks, pending transactions). Since RPC endpoints have varying rates, performance, and supported methods, the manager must intelligently route requests. Consider using services like Chainlist for verified RPC URLs or decentralized providers like Pocket Network to avoid single points of failure and ensure consistent uptime across all supported networks.

Security architecture must be chain-agnostic yet context-aware. The wallet core should enforce universal security policies, such as transaction simulation before signing and phishing domain detection. However, threat models differ per chain: EVM wallets must guard against malicious approve calls, while Solana wallets need to validate Program Derived Address (PDA) instructions. Each chain adapter should implement a validateTransaction method that checks for chain-specific risks, with findings bubbled up to the core security module for a unified user warning system.

Finally, design a modular provider injection system for maximum flexibility. Instead of bundling all chain adapters, allow users or developers to dynamically register new blockchain providers. This can be done via a plugin system or a standardized provider interface. The EIP-1193 standard for Ethereum providers is a good reference model. This approach future-proofs your wallet, enabling community-driven support for emerging Layer 1s and Layer 2s without requiring a full application update, aligning with the decentralized ethos of Web3.

A layer 1 agnostic wallet must interact with diverse blockchain networks like Ethereum, Solana, and Polygon. The core challenge is abstracting away the differences in their JSON-RPC APIs while maintaining performance and reliability. The architecture hinges on a provider management layer that can dynamically select, load balance, and failover between multiple RPC endpoints for each chain. This is critical because a single provider's downtime should not render your wallet unusable for a specific network.

Implementing this starts with a provider registry. For each supported chain (e.g., Ethereum Mainnet, Arbitrum, Base), you configure a list of RPC URLs from services like Alchemy, Infura, QuickNode, and public endpoints. Your client should include logic to rotate providers based on response time, success rate, and rate limit status. A common pattern is to use a primary provider for all requests but have a pre-initialized fallback provider that automatically takes over if the primary fails or times out after a configurable threshold.

For Ethereum Virtual Machine (EVM) chains, libraries like ethers.js or viem simplify this. You can create a FallbackProvider (ethers) or a custom Transport (viem) that wraps multiple RPC providers. Non-EVM chains like Solana or Sui require their own SDKs and similar wrapper logic. Your architecture must also handle chain-specific methods; an L1-agnostic adapter should map common wallet actions (e.g., getBalance, sendTransaction) to the correct underlying provider call, normalizing the response data into a consistent internal format.

State management is another key consideration. The wallet must track the current active provider for each chain and relevant metrics. This data can inform a provider health dashboard and automated switching logic. Furthermore, consider implementing request batching and caching for frequent, idempotent calls like fetching token prices or NFT metadata to reduce load on RPC endpoints and improve user experience, especially on mobile devices with limited bandwidth.

Finally, security and user sovereignty are paramount. While managed services offer convenience, allow advanced users to input custom RPC endpoints. Always validate the chain ID returned by the provider to prevent network spoofing attacks. Architecting with these principles results in a resilient wallet that provides a seamless, secure multi-chain experience, insulating users from the fragility of any single point of failure in the blockchain infrastructure layer.

A unified account abstraction layer decouples user accounts from the underlying blockchain's consensus and state management. Instead of managing separate private keys for Ethereum, Solana, and Aptos, users interact with a single, smart contract-based account that can initiate transactions on any connected chain. The core architectural challenge is designing a system where this abstracted account can validate and pay for transactions on heterogeneous Layer 1 networks, each with different virtual machines, fee models, and signature schemes.

The foundation is a cross-chain verification contract. This contract, deployed on each supported blockchain, holds the logic to validate proofs that a user's intent was authorized by their master account. A user signs a meta-transaction intent off-chain. A relayer network then submits this intent, along with a validity proof, to the verification contract on the target chain. This contract checks the proof against the user's known public key and, if valid, executes the desired action. This pattern separates authentication (proof verification) from execution (on-chain action).

Key components include a universal signature scheme and a gas abstraction mechanism. For signatures, you might use a secp256r1 key stored in a secure enclave, with signatures verified via a precompile, or implement ERC-4337-style signature aggregation. For gas, the verification contract must sponsor transactions. This requires a gas tank funded with the native token of each chain, replenished via cross-chain messages or a liquidity bridge, allowing users to pay fees in a single stablecoin or the wallet's native token.

Implementing this requires a state synchronization protocol. The user's unified account state—like nonce or deployed smart contract wallet addresses on new chains—must be consistent. A common approach is to use a canonical chain (like Ethereum) as the source of truth for the root account. Changes are emitted as events and relayed to light clients or oracles on other chains, updating the local verification contracts. This ensures a new chain can derive the user's correct address and authorization logic on first contact.

For developers, the entry point is a Software Development Kit (SDK) that abstracts chain-specific complexities. The SDK generates the user's deterministic address for any chain, crafts compliant transaction payloads, and interfaces with the relayer. A reference implementation might use Solidity for EVM chains, Move for Aptos/Sui, and Rust for Solana, with a core library in a language like Rust or Go handling the cross-chain state logic and proof generation.

The primary takeaway is that wallet agnosticism is an architectural choice, not a single feature. You achieve it by abstracting three core components: the signer interface (like EIP-1193), the provider/network layer (via RPC standards), and the transaction construction logic. This separation allows the core wallet logic to remain constant while swapping out chain-specific adapters. For example, your signMessage function would call a generic signer, which is implemented differently for an Ethereum EOA, a Solana wallet, or a StarkNet account.

Your next step should be to implement a minimal viable abstraction for one additional chain. Choose a chain with a distinctly different architecture, such as moving from Ethereum to Cosmos (with SDK-based transactions) or Bitcoin (with UTXO and script-based signing). Build a simple adapter that implements your core interfaces—signTransaction, getBalance, sendTransaction—for this new chain. This exercise will expose the true complexities of agnosticism, like handling different fee markets, address formats, and block explorers.

For production systems, rigorously test state management across chains. Use a deterministic derivation path standard like BIP-44 or SLIP-44, but be aware that not all chains use the same coin-type indices. Your key derivation library must be configurable. Furthermore, implement a chain registry—a maintained list of supported networks with their RPC endpoints, chain IDs, native currencies, and explorers. Projects like the Chainlist schema or the Cosmos Chain Registry provide excellent reference models.

Looking ahead, consider integrating account abstraction (AA) standards like ERC-4337 on Ethereum or its equivalents on other chains. AA introduces a new layer of agnosticism by separating the validation logic (smart contract accounts) from the underlying chain's transaction protocol. Supporting AA means your wallet can manage smart accounts that operate identically across multiple EVM chains, pushing chain-specific details further down the stack.

Finally, contribute to and rely on open standards. The evolution of Multi-Party Computation (MPC) and threshold signature schemes (TSS) is creating new paradigms for agnostic key management. Libraries like Web3Auth and Turnkey are building cross-chain SDKs that handle these complexities. By leveraging and contributing to these efforts, you avoid reinventing the wheel and help advance the interoperability of the entire ecosystem.