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About the Multichain API

Flask Only
This feature is experimental and only available in MetaMask Flask, the canary distribution of MetaMask.

The Multichain API is a scalable, generalized web3 wallet API that supports simultaneous interactions across multiple blockchain networks. When integrated with MetaMask Snaps, it enables developers to interact with both popular and emerging networks. Key benefits include:

  • Seamless network interactions - The Multichain API allows dapps to interact directly with multiple networks, without having to switch between single active networks. This enables smooth, integrated multichain user experience flows.

  • Scaling usage of non-EVM networks - The Multichain API integrates with interoperability Snaps, providing a standardized interface to encourage broader adoption of non-EVM networks.

  • Simplified integrations - The Multichain API reduces the complexity associated with navigating different wallet APIs and SDKs, making it easier for dapps to integrate with wallets, discover capabilities, and negotiate interfaces.

Get started using the Multichain API.

Technical overview​

The Multichain API follows the CAIP-25 standard for dapps to interface with multichain wallets. The API includes a method wallet_createSession that dapps can call to create a multichain connection with a wallet, with specified properties and authorization scopes. Dapps can update the connection using the same method wallet_createSession.

Dapps can use wallet_invokeMethod to call a subset of the Wallet JSON-RPC API methods on a specified chain. Dapps can use wallet_getSession to get the scopes and properties of the active connection, and use wallet_revokeSession to revoke the connection. The API also supports the following events:

  • wallet_notify notifies dapps of onchain events or state changes they previously subscribed to.
  • wallet_sessionChanged notifies dapps of changes to the multichain connection.

See the Multichain API reference for full details.

Lifecycle diagram​

The following sequence diagram illustrates the multichain connection lifecycle.

Backwards compatibility​

When using the Multichain API, your dapp can still interact with the existing Wallet Provider API. However, the Provider API is not optimized for multichain, and we recommend starting directly with the Multichain API if possible. The Multichain API is backwards compatible mainly to support dapps that use third-party libraries with dependencies on the legacy provider.

Get started​

Get started with the Multichain API: