@metamask/keyring-api

MetaMask Keyring API

This TypeScript module is maintained in the style of the MetaMask team.

This TypeScript module simplifies the integration of snaps with MetaMask using the Keyring API.

Features:

• Keyring API Interface: The module exposes an interface representing the Keyring API. Snaps can implement this interface to seamlessly interact with MetaMask and leverage its functionality.

• DApp Client: The module includes a client that enables dApps to communicate with the Keyring snap. This client allows dApps to send requests to the snap, such as retrieving account information or submitting requests.

• MetaMask Client: The module provides a client specifically designed for MetaMask integration. This client enables MetaMask to send requests directly to the Keyring snap, facilitating smooth interoperability between the two applications.

• Request Handler Helper Functions: The module offers a set of helper functions to simplify the implementation of the request handler in the Keyring snap. These functions assist in processing incoming requests, validating data, and handling various request types from dApps and MetaMask.

Installation

yarn add @metamask/keyring-api

or

npm install @metamask/keyring-api

Usage

In a snap

Inside the snap, implement the Keyring API:

class MySnapKeyring implements Keyring {
  // Implement the required methods.
}

Then create a handler that uses an instance of your keyring:

import { keyringRpcDispatcher } from '@metamask/keyring-api';

// Create a new MySnapKeyring instance
keyring = new MySnapKeyring(keyringState);
// ...

// And wrap it in a handler
const keyringHandler: OnRpcRequestHandler = async ({ request }) => {
  // Load the keyring state if needed
  // ...
  return await keyringRpcDispatcher(keyring, request);
};

Now expose this handler:

export const onRpcRequest: OnRpcRequestHandler = keyringHandler;

Or chain it with other handlers:

import { chainHandlers } from '@metamask/keyring-api';

export const onRpcRequest: OnRpcRequestHandler = chainHandlers(
  // Other handlers...
  keyringHandler,
  // Other handlers...
);

API

See our documentation:

• Latest published API documentation
• Latest development API documentation

Contributing

Setup

• Install Node.js version 16
  • If you are using nvm (recommended) running nvm use will automatically choose the right node version for you.
• Install Yarn v3
• Run yarn install to install dependencies and run any required post-install scripts

Testing and Linting

Run yarn test to run the tests once. To run tests on file changes, run yarn test:watch.

Run yarn lint to run the linter, or run yarn lint:fix to run the linter and fix any automatically fixable issues.

Release & Publishing

The project follows the same release process as the other libraries in the MetaMask organization. The GitHub Actions action-create-release-pr and action-publish-release are used to automate the release process; see those repositories for more information about how they work.

1. Choose a release version.

   • The release version should be chosen according to SemVer. Analyze the changes to see whether they include any breaking changes, new features, or deprecations, then choose the appropriate SemVer version. See the SemVer specification for more information.

2. If this release is backporting changes onto a previous release, then ensure there is a major version branch for that version (e.g. 1.x for a v1 backport release).

   • The major version branch should be set to the most recent release with that major version. For example, when backporting a v1.0.2 release, you'd want to ensure there was a 1.x branch that was set to the v1.0.1 tag.

3. Trigger the workflow_dispatch event manually for the Create Release Pull Request action to create the release PR.

   • For a backport release, the base branch should be the major version branch that you ensured existed in step 2. For a normal release, the base branch should be the main branch for that repository (which should be the default value).
   • This should trigger the action-create-release-pr workflow to create the release PR.

4. Update the changelog to move each change entry into the appropriate change category (See here for the full list of change categories, and the correct ordering), and edit them to be more easily understood by users of the package.

   • Generally any changes that don't affect consumers of the package (e.g. lockfile changes or development environment changes) are omitted. Exceptions may be made for changes that might be of interest despite not having an effect upon the published package (e.g. major test improvements, security improvements, improved documentation, etc.).
   • Try to explain each change in terms that users of the package would understand (e.g. avoid referencing internal variables/concepts).
   • Consolidate related changes into one change entry if it makes it easier to explain.
   • Run yarn auto-changelog validate --rc to check that the changelog is correctly formatted.

5. Review and QA the release.

   • If changes are made to the base branch, the release branch will need to be updated with these changes and review/QA will need to restart again. As such, it's probably best to avoid merging other PRs into the base branch while review is underway.

6. Squash & Merge the release.

   • This should trigger the action-publish-release workflow to tag the final release commit and publish the release on GitHub.

7. Publish the release on npm.

   • Wait for the publish-release GitHub Action workflow to finish. This should trigger a second job (publish-npm), which will wait for a run approval by the npm publishers team.
   • Approve the publish-npm job (or ask somebody on the npm publishers team to approve it for you).
   • Once the publish-npm job has finished, check npm to verify that it has been published.

Changelog

[0.1.1]

Added

• Validate snap responses for type correctness (#15).

Changed

• Rename RPC handling functions (#16).