A user holding Bitcoin, Ethereum, and Solana across three separate portfolios faces a practical frustration: they need at least two wallets to manage all three assets. Rabby Wallet handles Ethereum and EVM-compatible networks seamlessly, but it cannot touch Bitcoin or Solana natively. That limitation is not an oversight or a feature roadmap item waiting for development resources. It is a direct consequence of how these blockchains work at a protocol level. Understanding why that constraint exists—and what it means for multi-chain users—requires clarity about what an EVM wallet actually is and why it cannot be stretched to cover incompatible systems.

The gap also exposes a broader principle about blockchain design. Bitcoin and Solana use fundamentally different account models, signature schemes, transaction formats, and consensus mechanisms than Ethereum. A wallet built for one architecture cannot simply add support for another without rebuilding core components. This article examines why that technical barrier exists, how it shapes wallet design, and the practical strategies users employ to manage assets across incompatible networks without consolidating their security model or resorting to custodial exchanges.

What makes an EVM wallet distinct from a universal wallet

The Ethereum Virtual Machine is an abstract computational framework that defines how transactions are structured, validated, and executed. An EVM wallet is purpose-built to create, sign, and broadcast transactions that conform to EVM specifications. This includes encoding transaction data with specific fields: the recipient address, the amount of value being sent, optional bytecode (for smart contract interactions), gas price parameters, nonce counters, and a signature created with the private key. Any blockchain that implements the EVM specification can work with wallets designed for that standard.

Rabby Wallet supports Arbitrum, Optimism, Base, Polygon, and BNB Smart Chain precisely because they are all EVM-compatible. They may differ in consensus mechanism, block time, and native token, but they accept the same transaction format, require the same address type, and validate signatures using the same cryptographic scheme (ECDSA with the secp256k1 curve). A single private key can derive valid addresses on all of them. When a user switches networks within Rabby, they are not changing the underlying key material or the wallet logic; they are simply pointing the transaction construction at a different RPC endpoint and a different chain ID.

Bitcoin is not EVM-compatible, and neither is Solana. Bitcoin uses ECDSA with the secp256k1 curve for signatures—the same as Ethereum—but everything else diverges. Bitcoin transactions use a UTXO (Unspent Transaction Output) model rather than accounts with nonces. An address is derived from a public key using different hashing functions and encoding schemes. The transaction format is binary, not the ABI-encoded format used by Ethereum. Fee calculation, input selection, change address handling, and script validation follow completely different rules. A wallet built to construct Bitcoin transactions must understand UTXOs, script semantics, and Bitcoin’s specific input-output model. Rabby simply does not implement any of that logic.

Solana introduces additional incompatibilities. It does not use ECDSA or secp256k1. It uses the Ed25519 signature scheme, which is faster and more compact but produces a different key pair structure. Solana addresses are 32-byte public keys encoded in base58, not the 20-byte Ethereum-style addresses derived from Keccak-256 hashes. Transaction construction requires program addresses, account references, rent calculations, and transaction versioning that have no counterpart in the EVM. An Ethereum private key cannot directly control a Solana wallet. Attempting to use the same seed phrase would require deriving keys using a different derivation path and then interpreting those keys under Solana’s signature rules—which would likely fail or produce incorrect results.

The account model difference: accounts and nonces versus UTXOs and pubkeys

Ethereum and EVM chains use an account model. Every address is associated with a persistent account object on the blockchain, containing a nonce (transaction counter), balance, code (if smart contract), and storage. When a user creates a transaction, it increments the account’s nonce. The network validates that the nonce is the next expected value, preventing replay attacks and imposing a strict ordering on transactions from one address. This model simplifies user experience: a wallet displays a single balance, tracks the nonce internally, and broadcasts transactions without worrying about discrete pieces of value.

Bitcoin uses a UTXO model. Instead of accounts, there are unspent transaction outputs. Each output represents discrete funds locked by a script (typically a signature requirement). To spend those funds, a transaction must reference the output as an input, provide the correct signature or other proof, and create new outputs as destinations. A single address might have multiple UTXOs scattered across different transactions, and spending requires selecting which UTXOs to combine. This creates both power and friction: a user can have fine-grained control over which funds go where, but they must also understand concepts like change addresses, input selection, and fee-per-byte estimation.

The distinction affects how wallets work at every level. An EVM wallet like Rabby can fetch the account balance from a single place, display it clearly, and construct a transaction by specifying a destination and amount. The blockchain will reject the transaction if the nonce is wrong, but the wallet’s logic remains straightforward. A Bitcoin wallet must scan the blockchain to find all UTXOs belonging to the user’s addresses, calculate the total, and then run coin selection logic to decide which UTXOs to spend. If coin selection is careless, the user might unnecessarily expose separate payment contexts or increase fees. If it is done well, it improves privacy and efficiency. That choice reflects a different model entirely.

Solana is closer to Ethereum in its account-based design, but the details again diverge. Solana accounts are program-derived and can hold lamports (the native token), token balances (via token program accounts), or arbitrary data. Transactions must reference all accounts involved as separate fields. Fee calculation depends on the size of the transaction and account state changes, not a gas market. A Solana wallet must understand which accounts are involved in a transaction, whether they are signable or read-only, and whether they need to be created or rent-exempted. None of these concepts map directly to EVM wallets.

Signature schemes and key derivation: why the same seed phrase does not work everywhere

Ethereum uses ECDSA with the secp256k1 curve and derives addresses using Keccak-256 hashing. A seed phrase (BIP39 standard) generates a master key, from which child keys are derived using BIP44 paths. The standard path for Ethereum is m/44'/60'/0'/0/0, where 60 is the SLIP44 coin type identifier for Ethereum. The resulting private key is used to sign transactions, and the public key is hashed to produce a 20-byte address.

Bitcoin also uses ECDSA secp256k1 and BIP39 seed phrases but employs different derivation paths and address encoding. The standard path is m/44'/0'/0'/0/0, where 0 is Bitcoin’s identifier. Bitcoin also has multiple address types: legacy (Pay-to-PubKey-Hash), SegWit (Pay-to-Witness-PubKey-Hash), and Taproot (Pay-to-Taproot). Each type uses different encoding and script validation. A key derived from the same seed phrase under Ethereum’s path will not match the key derived under Bitcoin’s path, and even if it did, the address encoding would be incompatible.

Solana uses Ed25519, an entirely different curve. A seed phrase cannot simply be reinterpreted under Ed25519 logic without a complete key derivation redesign. Solana’s standard derivation path is m/44'/501'/0'/0', where 501 is Solana’s identifier, and the derivation process produces Ed25519 keys. A private key derived this way is incompatible with secp256k1 applications. This is why a user cannot import their Ethereum seed phrase into a Solana wallet and expect to access the same funds. The paths produce different keys, the curves are different, and even the address encoding is different.

Some wallet applications (like Phantom for Solana or Trust Wallet as a multi-chain solution) manage multiple key derivation paths from a single seed phrase, allowing the user to hold Ethereum and Solana assets from the same recovery phrase but with completely separate keys. Rabby does not do this. As an EVM wallet, it is designed to generate and manage only EVM-compatible keys. Adding Solana or Bitcoin support would require implementing additional key derivation logic, signature verification, and transaction construction—essentially building a second wallet inside the first application.

Transaction construction and validation: why one format cannot cover all networks

An EVM transaction is a structured object with fields: nonce, gasPrice (or maxFeePerGas and maxPriorityFeePerGas for EIP-1559), gasLimit, to, value, data, v, r, s (the signature). The wallet encodes these fields using RLP (Recursive Length Prefix) and signs the hash with the private key. The resulting transaction is broadcast to nodes, which validate the signature, check the nonce, estimate gas usage, and execute the transaction against the blockchain’s state.

A Bitcoin transaction is binary-encoded and contains inputs (previous UTXOs being spent), outputs (new funds destinations), a locktime, and version. Each input requires a witness (signature and possibly pubkey) that satisfies the script guarding that UTXO. Fee calculation is manual: the wallet sums input values, sums output values, and the difference is the fee. Transaction size in bytes determines fee-per-byte, which the user or wallet must estimate. Segwit and Taproot transactions use witness data, which has different size calculations and signing procedures.

A Solana transaction lists instructions (which program to call and what accounts to touch), signers (which accounts must sign), recent blockhash (for replay prevention instead of nonce), and signatures. Instructions are encoded as specific program-defined structures, not generic bytecode. Fee calculation depends on the compute units consumed, not transaction size. Signing in Solana is simpler (no nonce management) but requires understanding account roles and instruction semantics.

The consequence is that a wallet cannot be truly universal without reimplementing each transaction model from scratch. Rabby focuses on EVM correctness, including transaction simulation to show the user what will happen before execution, DeFi protocol understanding to decode complex interactions, and approval review to prevent phishing. These features are valuable precisely because they are EVM-specific. Extending them to Bitcoin’s UTXO model or Solana’s instruction-based system would require building equivalent features for each, which is a large undertaking and beyond the wallet’s current design philosophy.

The multi-wallet strategy: practical approaches for users managing diverse assets

Users with Bitcoin, Ethereum, and Solana holdings should expect to use multiple wallets. The most practical approach is to assign each wallet a specific purpose. Rabby handles all EVM assets and interactions: Ethereum, Arbitrum, Optimism, Base, Polygon, and other EVM chains. For Bitcoin, specialized wallets like Electrum, Blue Wallet, Sparrow, or hardware wallet interfaces can handle UTXO selection, fee estimation, and address management. For Solana, Phantom, Magic Eden’s wallet, or Solflare can manage Ed25519 keys and Solana-specific account logic.

This separation is not merely a limitation; it can be a security feature. Each wallet holds a separate seed phrase. If one wallet is compromised or even lost, the others remain untouched. A user can store the EVM seed phrase in one location, the Bitcoin seed phrase in another, and the Solana seed phrase in a third. This requires managing multiple recovery phrases and remembering which is which, but it reduces the blast radius of any single breach. A phishing attack targeting Rabby cannot steal Bitcoin or Solana funds. A malicious browser extension that intercepts Ethereum approvals cannot access Bitcoin UTXOs or Solana token accounts.

For users who prefer fewer recovery phrases, multi-asset wallets like Trust Wallet, Exodus, or Edge can derive keys for multiple chains from a single seed. These wallets implement the key derivation logic for Ethereum, Bitcoin, Solana, and many others, allowing a single seed phrase to control assets across incompatible networks. The trade-off is accepting a more general-purpose wallet rather than Rabby’s EVM-focused security features like transaction simulation and approval review. You can download rabby wallet app from the official site if you want to focus primarily on EVM assets while maintaining strong transaction transparency.

Hardware wallet users have another option: devices like Ledger or Trezor store private keys offline and support both EVM and non-EVM chains through their browser interfaces or companion apps. The user can import the hardware wallet into Rabby for EVM transactions and into other applications for Bitcoin or Solana, with the same seed phrase underlying all of them. This approach offers strong security (keys never leave the device) and operational simplicity (one recovery phrase) but requires the user to manage the hardware wallet connection and understand which software wallet to use for each chain.

What this architectural boundary implies for wallet design and development

The inability to support Bitcoin and Solana is not a drawback in Rabby’s design; it is a consequence of choosing depth over breadth. By focusing exclusively on EVM-compatible networks, Rabby can invest in features that matter specifically for EVM users: transaction simulation that runs the transaction against chain state to show what will actually happen, gas optimization and fee preview, decentralized application interaction with readable and reviewable transaction details, and NFT display with chain-specific metadata handling. These features rely on EVM infrastructure assumptions. They would require substantial rework to extend meaningfully to Bitcoin or Solana.

Bitcoin transactions, for instance, cannot be meaningfully simulated in the same way because Bitcoin does not have a global execution model like the EVM. Coin selection strategies, fee-per-byte calculations, and script validation are distinct problems. Solana’s instruction-based model could theoretically support simulation through Solana’s runtime, but integrating that would require understanding Solana-specific programs and account relationships. The feature set that makes Rabby valuable for Ethereum users would need to be rebuilt separately for each new chain.

This decision also affects update cycles and security audits. An EVM-focused wallet can be thoroughly tested and audited for the specific chains it supports. Adding Bitcoin or Solana would expand the attack surface and introduce new failure modes: incorrect UTXO selection, flawed change address handling, derivation path confusion, or Solana-specific rent and account-creation logic. Each new chain increases the testing burden and the complexity of the codebase. For users who depend on Rabby’s current reliability, maintaining that narrower scope is often preferable to chasing broader compatibility.

The open-source nature of Rabby (code published on GitHub) also means that developers are free to contribute Bitcoin or Solana support if they choose. To date, no such contribution has been merged, likely because the cost-benefit analysis does not favor it. A more likely future is that Rabby remains an excellent EVM wallet while users adopt a complementary Bitcoin or Solana wallet for those respective assets. This is not a failure of design; it is an honest acknowledgment of protocol-level incompatibilities.

Avoiding common misconceptions about wallet universality

One frequent misunderstanding is that a wallet is primarily a storage mechanism and should therefore support any asset. In reality, a wallet is a transaction construction and signing tool. It must understand the specific rules of each blockchain to create valid transactions. A universal wallet is not like a universal remote control that can adapt to any device; it is more like a vehicle that must be redesigned for each terrain. A car designed for roads cannot navigate a river, and adding pontoons does not address the fundamental steering and engine differences required.

Another misconception is that blockchain incompatibility is a temporary state awaiting a bridge or wrapper solution. Bitcoin and Solana do not have fundamental flaws that need fixing. They were designed with different priorities: Bitcoin prioritized security, decentralization, and immutability; Solana prioritized speed and throughput. Wrapped tokens (like WBTC on Ethereum) exist, but they require a custodian or multisig signer to hold the underlying Bitcoin. That introduces counterparty risk and does not allow a user to transact in Bitcoin natively. Rabby cannot support wrapped Bitcoin because WBTC is an ERC-20 token on Ethereum, not actual Bitcoin.

A third misconception is that using multiple wallets is inconvenient and therefore unnecessary. In practice, most users with diverse holdings already accept that reality. A Bitcoin maximalist uses a Bitcoin wallet; a Solana developer uses Phantom; an Ethereum DeFi user uses Rabby or MetaMask. The friction is minimal if each wallet is used for its designed purpose. The real inconvenience would be trying to force one wallet to do everything poorly rather than using each tool well. For users new to cryptocurrency, starting with a single wallet for a single chain, then adding specialized wallets as portfolios diversify, is often the most practical path.

Future directions and the limits of interoperability

Cross-chain bridges and liquidity aggregators (like 1inch or Curve’s multichain offerings) allow users to move assets between chains, but they do not give one wallet native support for incompatible chains. These services typically work through wrapped assets, atomic swaps, or liquidity pools. A user can swap Ethereum for Bitcoin through a decentralized exchange on Arbitrum, receiving WBTC, but that is not the same as Rabby natively handling Bitcoin. To access actual Bitcoin, the user must withdraw to a Bitcoin wallet.

Some projects are exploring interoperability layers (like IBC for Cosmos chains) or shared security models (like Ethereum validators participating in other chains). These approaches might eventually allow assets to be used across more networks, but they do not solve the fundamental problem: Rabby is designed for EVM chains. Even if Bitcoin became EVM-compatible through some hypothetical upgrade (which would require abandoning Bitcoin’s core design), Rabby would still need to implement Bitcoin-specific features to be truly useful for Bitcoin users. Interoperability is about moving assets, not changing what a wallet actually is.

The most realistic future for Rabby is continued refinement within its scope: better cross-chain swap integration, improved NFT standards support, enhanced DeFi safety features, and expansion to every EVM-compatible chain that gains significant adoption. For Bitcoin and Solana, the ecosystem will continue to favor specialized wallets. This is not a design failure; it reflects honest boundaries and deep expertise. A user with diverse holdings benefits from this division of labor more than from a mythical wallet that does everything equally well.