@sei-js/metamask-snap

Sei Metamask Snap

This documentation describes the functions and RPC request handler used in a MetaMask Snap to handle cryptocurrency transactions and account management using BIP44 standards.

onRpcRequest

An RPC request handler that processes different request methods including signDirect, signAmino, and getPrivateKey. It handles the signing of transactions both in Amino and Direct mode, and also retrieves the private key.

• Syntax: onRpcRequest({ request }): Promise<TransactionSignature | PrivateKey>
• Parameters:
  • request: An object representing the RPC request.
• Returns: A Promise that resolves to a TransactionSignature or PrivateKey.

RPC Methods

signDirect

Signs a transaction in Direct mode.

• Parameters:
  • account_index: The bip44 coin type 118 account index to use for signing.
  • signerAddress: The address of the signer.
  • signDoc: The document to be signed.
• Error Handling: Throws an error if the private key is not available or if the user denies the transaction.

signAmino

Signs a transaction in Amino mode.

• Parameters:
  • account_index: The bip44 coin type 118 account index to use for signing.
  • signerAddress: The address of the signer.
  • signDoc: The document to be signed.
  • enableExtraEntropy: Boolean flag for extra entropy.
  • isADR36: Boolean flag for ADR-36 compliance.
• Error Handling: Throws an error if the private key is not available or if the user denies the transaction.

getPrivateKey

Retrieves the private key for a specified account index using MetaMask's snap_getBip44Entropy method and BIP44 standards and coin type 118.

• Syntax: getPrivateKey(account_index: number = 0): Promise<PrivateKey>
• Parameters:
  • account_index (number, optional): The index of the account, defaulting to 0.
• Returns: A Promise resolving to a PrivateKey.

Local development and testing

Setup

Run yarn to install dependencies.

Running the snap locally

In order to run the snap locally simply run yarn start and the snap will be served at localhost:8080.

Testing the snap

Test UI

This package has a helpful UI for testing all the exposed functions.

cd into the ./test-ui directory and run yarn to install dependencies. Then run yarn dev to start the test UI. The test UI will be served at localhost:3000. Please checkout the README.md in that directory to learn how to set the snap ID.

Unit tests

Run yarn test to run the unit tests.