feat: add multichain-account-service (readonly)

.github/CODEOWNERS

@@ -7,9 +7,10 @@
 /.github/                            @MetaMask/core-platform
 
 ## Accounts Team
-/packages/accounts-controller        @MetaMask/accounts-engineers
+/packages/accounts-controller                @MetaMask/accounts-engineers
 /packages/multichain-transactions-controller @MetaMask/accounts-engineers
-/packages/account-tree-controller @MetaMask/accounts-engineers
+/packages/multichain-account-controller      @MetaMask/accounts-engineers
+/packages/account-tree-controller            @MetaMask/accounts-engineers
 
 ## Assets Team
 /packages/assets-controllers         @MetaMask/metamask-assets

README.md

@@ -48,6 +48,7 @@ Each package in this repository has its own README where you can find installati
 - [`@metamask/logging-controller`](packages/logging-controller)
 - [`@metamask/message-manager`](packages/message-manager)
 - [`@metamask/messenger`](packages/messenger)
+- [`@metamask/multichain-account-controller`](packages/multichain-account-controller)
 - [`@metamask/multichain-api-middleware`](packages/multichain-api-middleware)
 - [`@metamask/multichain-network-controller`](packages/multichain-network-controller)
 - [`@metamask/multichain-transactions-controller`](packages/multichain-transactions-controller)
@@ -106,6 +107,7 @@ linkStyle default opacity:0.5
   logging_controller(["@metamask/logging-controller"]);
   message_manager(["@metamask/message-manager"]);
   messenger(["@metamask/messenger"]);
+  multichain_account_controller(["@metamask/multichain-account-controller"]);
   multichain_api_middleware(["@metamask/multichain-api-middleware"]);
   multichain_network_controller(["@metamask/multichain-network-controller"]);
   multichain_transactions_controller(["@metamask/multichain-transactions-controller"]);

package.json

@@ -47,7 +47,11 @@
   "resolutions": {
     "elliptic@6.5.4": "^6.5.7",
     "fast-xml-parser@^4.3.4": "^4.4.1",
-    "ws@7.4.6": "^7.5.10"
+    "ws@7.4.6": "^7.5.10",
+    "@metamask/keyring-utils@^3.0.0": "npm:@metamask-previews/keyring-utils@3.0.0-e86c8ec",
+    "@metamask/keyring-api@^18.0.0": "npm:@metamask-previews/keyring-api@18.0.0-e86c8ec",
+    "@metamask/keyring-internal-api@^6.2.0": "npm:@metamask-previews/keyring-internal-api@6.2.0-e86c8ec",
+    "@metamask/account-api@^0.1.0": "npm:@metamask-previews/account-api@0.1.0-e86c8ec"
   },
   "devDependencies": {
     "@babel/core": "^7.23.5",

packages/multichain-account-controller/CHANGELOG.md

@@ -0,0 +1,10 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [Unreleased]
+
+[Unreleased]: https://github.com/MetaMask/core/

packages/multichain-account-controller/LICENSE

@@ -0,0 +1,20 @@
+MIT License
+
+Copyright (c) 2025 MetaMask
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

packages/multichain-account-controller/README.md

@@ -0,0 +1,17 @@
+# `@metamask/multichain-account-controller`
+
+Multichain account stateless controller.
+
+This controller provides operations and functionalities around multichain accounts and wallets.
+
+## Installation
+
+`yarn add @metamask/multichain-account-controller`
+
+or
+
+`npm install @metamask/multichain-account-controller`
+
+## Contributing
+
+This package is part of a monorepo. Instructions for contributing can be found in the [monorepo README](https://github.com/MetaMask/core#readme).

packages/multichain-account-controller/jest.config.js

@@ -0,0 +1,26 @@
+/*
+ * For a detailed explanation regarding each configuration property and type check, visit:
+ * https://jestjs.io/docs/configuration
+ */
+
+const merge = require('deepmerge');
+const path = require('path');
+
+const baseConfig = require('../../jest.config.packages');
+
+const displayName = path.basename(__dirname);
+
+module.exports = merge(baseConfig, {
+  // The display name when running multiple projects
+  displayName,
+
+  // An object that configures minimum threshold enforcement for coverage results
+  coverageThreshold: {
+    global: {
+      branches: 100,
+      functions: 100,
+      lines: 100,
+      statements: 100,
+    },
+  },
+});

packages/multichain-account-controller/package.json

@@ -0,0 +1,91 @@
+{
+  "name": "@metamask/multichain-account-controller",
+  "version": "0.0.0",
+  "description": "Controller to manage multichain accounts",
+  "keywords": [
+    "MetaMask",
+    "Ethereum"
+  ],
+  "homepage": "https://github.com/MetaMask/core/tree/main/packages/multichain-account-controller#readme",
+  "bugs": {
+    "url": "https://github.com/MetaMask/core/issues"
+  },
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/MetaMask/core.git"
+  },
+  "license": "MIT",
+  "sideEffects": false,
+  "exports": {
+    ".": {
+      "import": {
+        "types": "./dist/index.d.mts",
+        "default": "./dist/index.mjs"
+      },
+      "require": {
+        "types": "./dist/index.d.cts",
+        "default": "./dist/index.cjs"
+      }
+    },
+    "./package.json": "./package.json"
+  },
+  "main": "./dist/index.cjs",
+  "types": "./dist/index.d.cts",
+  "files": [
+    "dist/"
+  ],
+  "scripts": {
+    "build": "ts-bridge --project tsconfig.build.json --verbose --clean --no-references",
+    "build:docs": "typedoc",
+    "changelog:update": "../../scripts/update-changelog.sh @metamask/multichain-account-controller",
+    "changelog:validate": "../../scripts/validate-changelog.sh @metamask/multichain-account-controller",
+    "publish:preview": "yarn npm publish --tag preview",
+    "since-latest-release": "../../scripts/since-latest-release.sh",
+    "test": "NODE_OPTIONS=--experimental-vm-modules jest --reporters=jest-silent-reporter",
+    "test:clean": "NODE_OPTIONS=--experimental-vm-modules jest --clearCache",
+    "test:verbose": "NODE_OPTIONS=--experimental-vm-modules jest --verbose",
+    "test:watch": "NODE_OPTIONS=--experimental-vm-modules jest --watch"
+  },
+  "dependencies": {
+    "@metamask/account-api": "^0.1.0",
+    "@metamask/base-controller": "^8.0.1",
+    "@metamask/keyring-api": "^18.0.0",
+    "@metamask/keyring-internal-api": "^6.2.0",
+    "@metamask/keyring-snap-client": "^5.0.0",
+    "@metamask/snaps-sdk": "^9.0.0",
+    "@metamask/snaps-utils": "^11.0.0",
+    "@metamask/superstruct": "^3.1.0"
+  },
+  "devDependencies": {
+    "@metamask/accounts-controller": "^31.0.0",
+    "@metamask/auto-changelog": "^3.4.4",
+    "@metamask/eth-snap-keyring": "^13.0.0",
+    "@metamask/keyring-controller": "^22.1.0",
+    "@metamask/providers": "^22.1.0",
+    "@metamask/snaps-controllers": "^14.0.1",
+    "@types/jest": "^27.4.1",
+    "@types/uuid": "^8.3.0",
+    "deepmerge": "^4.2.2",
+    "jest": "^27.5.1",
+    "ts-jest": "^27.1.4",
+    "typedoc": "^0.24.8",
+    "typedoc-plugin-missing-exports": "^2.0.0",
+    "typescript": "~5.2.2",
+    "uuid": "^8.3.2",
+    "webextension-polyfill": "^0.12.0"
+  },
+  "peerDependencies": {
+    "@metamask/accounts-controller": "^31.0.0",
+    "@metamask/keyring-controller": "^22.0.0",
+    "@metamask/providers": "^22.0.0",
+    "@metamask/snaps-controllers": "^14.0.0",
+    "webextension-polyfill": "^0.10.0 || ^0.11.0 || ^0.12.0"
+  },
+  "engines": {
+    "node": "^18.18 || >=20"
+  },
+  "publishConfig": {
+    "access": "public",
+    "registry": "https://registry.npmjs.org/"
+  }
+}