| title | MetaMask Connect Multichain - Cross-Chain Wallet API | |||||||||||
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| sidebar_label | Introduction | |||||||||||
| toc_max_heading_level | 2 | |||||||||||
| description | Connect to Ethereum, Solana, and other blockchain ecosystems from a single session using the MetaMask Connect Multichain API built on CAIP-25. | |||||||||||
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import CardList from '@site/src/components/CardList'
Use MetaMask Connect Multichain (@metamask/connect-multichain) to connect to multiple blockchain networks and ecosystems in MetaMask at the same time.
With the multichain client, your dapp can request access to EVM networks, Solana, and future ecosystems in a single connection prompt, instead of using separate connection flows for each chain. This gives you more control than the ecosystem-specific clients, but requires adapting your dapp to work with the Multichain API rather than traditional per-chain RPC.
:::tip Ready to code? Jump to the Quickstart to set up MetaMask Connect Multichain in minutes. :::
MetaMask Connect Multichain is built on the Multichain API (CAIP-25) specification, a chain-agnostic standard for wallet-dapp communication. For the full rationale and specification, see MetaMask Improvement Proposal-5 (MIP-5).
Instead of connecting to one chain at a time, the Multichain API lets you:
- Request access to multiple ecosystems at once: For example, request Ethereum Mainnet, Polygon, and Solana Mainnet in a single session.
- Send requests to any chain in the session: For example, send a Solana transaction and an EVM transaction through the same connection.
- Manage the full session lifecycle: Connect, retrieve session data, invoke methods on any chain, and disconnect using SDK methods that wrap the underlying Multichain API.
For dapps that support both EVM and Solana, this means one session covers both, and users see a single approval prompt.
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The multichain client is a good fit when you're:
- Building a new dapp designed from the ground up for multiple ecosystems.
- Looking for the best cross-chain UX: one connection prompt for all chains.
- Needing full control over the session lifecycle.
If you're adding MetaMask Connect Multichain to an existing dapp and want minimal code changes, the ecosystem-specific clients (@metamask/connect-evm or @metamask/connect-solana) are a simpler starting point. You can always migrate later.
<CardList items={[ { href: '/metamask-connect/multichain/quickstart/javascript', title: 'Quickstart', description: 'Get started with MetaMask Connect Multichain in minutes.', }, { href: '/metamask-connect/multichain/guides/sign-transactions', title: 'Sign messages', description: 'Sign messages and typed data on EVM and Solana.', }, { href: '/metamask-connect/multichain/guides/send-transactions', title: 'Send transactions', description: 'Send transactions on EVM networks and Solana.', }, { href: '/metamask-connect/multichain/tutorials/create-multichain-dapp', title: 'Create a multichain dapp', description: 'Build a React dapp that connects to Ethereum, Linea, Base, and Solana.', }, { href: '/metamask-connect/multichain/reference/methods', title: 'SDK methods', description: 'See the reference for connect, invokeMethod, disconnect, and more.', }, { href: '/metamask-connect/multichain/reference/api', title: 'API reference', description: 'See the full Multichain API method and event reference.', }, ]} />
MetaMask Connect Multichain supports all EVM-compatible networks (Ethereum, Polygon, Arbitrum, Optimism, Linea, Base, and any chain with a CAIP-2 scope) and Solana (mainnet and devnet).
Future ecosystems will be supported as they are added to MetaMask.
Specify which chains to connect to using CAIP-2 scopes (for example, eip155:1 for Ethereum Mainnet or solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp for Solana Mainnet).
CAIP-25 is a chain-agnostic standard for wallet-dapp communication. When your dapp calls connect with a list of CAIP-2 scopes, MetaMask creates a session that authorizes your dapp to send requests to those chains. You then use invokeMethod to send JSON-RPC requests to any authorized chain by specifying its scope. The user sees a single approval prompt for all requested chains.
The multichain client and ecosystem-specific clients share the same underlying session infrastructure. While you can use both, we recommend choosing one approach. The multichain client gives you full control over sessions and cross-chain RPC, while the ecosystem-specific clients provide familiar per-chain provider interfaces. See integration options for a detailed comparison.