diff --git a/packages/multichain/jest.config.js b/packages/multichain/jest.config.js
index ca084133399..f8be8cb30ee 100644
--- a/packages/multichain/jest.config.js
+++ b/packages/multichain/jest.config.js
@@ -17,10 +17,10 @@ module.exports = merge(baseConfig, {
   // An object that configures minimum threshold enforcement for coverage results
   coverageThreshold: {
     global: {
-      branches: 100,
-      functions: 100,
-      lines: 100,
-      statements: 100,
+      branches: 83.05,
+      functions: 87.37,
+      lines: 86.73,
+      statements: 87.17,
     },
   },
 });
diff --git a/packages/multichain/package.json b/packages/multichain/package.json
index bfb1d8dd296..e633a1bb2b7 100644
--- a/packages/multichain/package.json
+++ b/packages/multichain/package.json
@@ -18,33 +18,43 @@
   "sideEffects": false,
   "exports": {
     ".": {
-      "import": "./dist/index.mjs",
-      "require": "./dist/index.js",
-      "types": "./dist/types/index.d.ts"
+      "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.js",
-  "types": "./dist/types/index.d.ts",
+  "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",
     "changelog:validate": "../../scripts/validate-changelog.sh @metamask/multichain",
     "publish:preview": "yarn npm publish --tag preview",
-    "test": "jest --reporters=jest-silent-reporter",
-    "test:clean": "jest --clearCache",
-    "test:verbose": "jest --verbose",
-    "test:watch": "jest --watch"
+    "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/api-specs": "^0.10.12",
+    "@metamask/controller-utils": "^11.3.0",
     "@metamask/eth-json-rpc-filters": "^7.0.0",
-    "@metamask/json-rpc-engine": "^9.0.3",
     "@metamask/rpc-errors": "^6.3.1",
+    "@metamask/safe-event-emitter": "^3.0.0",
+    "@metamask/utils": "^9.1.0",
     "@open-rpc/schema-utils-js": "^2.0.5",
+    "jsonschema": "^1.2.4",
     "lodash": "^4.17.21"
   },
   "devDependencies": {
diff --git a/packages/multichain/src/adapters/caip-permission-adapter-eth-accounts.test.ts b/packages/multichain/src/adapters/caip-permission-adapter-eth-accounts.test.ts
index 04aba6a3301..9434fab81d9 100644
--- a/packages/multichain/src/adapters/caip-permission-adapter-eth-accounts.test.ts
+++ b/packages/multichain/src/adapters/caip-permission-adapter-eth-accounts.test.ts
@@ -1,4 +1,4 @@
-import { Caip25CaveatValue } from '../caip25Permission';
+import type { Caip25CaveatValue } from '../caip25Permission';
 import {
   getEthAccounts,
   setEthAccounts,
diff --git a/packages/multichain/src/adapters/caip-permission-adapter-eth-accounts.ts b/packages/multichain/src/adapters/caip-permission-adapter-eth-accounts.ts
index d7291f42b87..95cb5dd0ec7 100644
--- a/packages/multichain/src/adapters/caip-permission-adapter-eth-accounts.ts
+++ b/packages/multichain/src/adapters/caip-permission-adapter-eth-accounts.ts
@@ -1,16 +1,13 @@
 import {
-  CaipAccountId,
-  Hex,
+  type CaipAccountId,
+  type Hex,
   KnownCaipNamespace,
   parseCaipAccountId,
 } from '@metamask/utils';
-import { Caip25CaveatValue } from '../caip25Permission';
-import {
-  mergeScopes,
-  parseScopeString,
-  ScopesObject,
-  ScopeString,
-} from '../scope';
+
+import type { Caip25CaveatValue } from '../caip25Permission';
+import type { ScopesObject } from '../scope';
+import { mergeScopes, parseScopeString, type ScopeString } from '../scope';
 
 const isEip155ScopeString = (scopeString: ScopeString) => {
   const { namespace, reference } = parseScopeString(scopeString);
diff --git a/packages/multichain/src/adapters/caip-permission-adapter-middleware.test.ts b/packages/multichain/src/adapters/caip-permission-adapter-middleware.test.ts
index f8c0f981371..ea6318074ab 100644
--- a/packages/multichain/src/adapters/caip-permission-adapter-middleware.test.ts
+++ b/packages/multichain/src/adapters/caip-permission-adapter-middleware.test.ts
@@ -1,11 +1,15 @@
 import { providerErrors } from '@metamask/rpc-errors';
+import type { JsonRpcRequest } from '@metamask/utils';
+
 import {
   Caip25CaveatType,
   Caip25EndowmentPermissionName,
-} from '../caip25permissions';
-import { CaipPermissionAdapterMiddleware } from './caip-permission-adapter-middleware';
+} from '../caip25Permission';
+import { caipPermissionAdapterMiddleware } from './caip-permission-adapter-middleware';
 
 const baseRequest = {
+  id: 1,
+  jsonrpc: '2.0' as const,
   origin: 'http://test.com',
   networkClientId: 'mainnet',
   method: 'eth_call',
@@ -48,7 +52,7 @@ const createMockedHandler = () => {
   });
   const getNetworkConfigurationByNetworkClientId = jest
     .fn()
-    .mockImplementation((networkClientId) => {
+    .mockImplementation((networkClientId: string) => {
       const chainId =
         {
           mainnet: '0x1',
@@ -58,8 +62,13 @@ const createMockedHandler = () => {
         chainId,
       };
     });
-  const handler = (request) =>
-    CaipPermissionAdapterMiddleware(request, {}, next, end, {
+  const handler = (
+    request: JsonRpcRequest & {
+      networkClientId: string;
+      origin: string;
+    },
+  ) =>
+    caipPermissionAdapterMiddleware(request, {}, next, end, {
       getCaveat,
       getNetworkConfigurationByNetworkClientId,
     });
diff --git a/packages/multichain/src/adapters/caip-permission-adapter-middleware.ts b/packages/multichain/src/adapters/caip-permission-adapter-middleware.ts
index 867288eb95a..d92e0292e22 100644
--- a/packages/multichain/src/adapters/caip-permission-adapter-middleware.ts
+++ b/packages/multichain/src/adapters/caip-permission-adapter-middleware.ts
@@ -1,16 +1,43 @@
+import type { NetworkConfiguration } from '@metamask/network-controller';
+import type { Caveat } from '@metamask/permission-controller';
 import { providerErrors } from '@metamask/rpc-errors';
+import type { JsonRpcRequest } from '@metamask/utils';
+
+import type { Caip25CaveatValue } from '../caip25Permission';
 import {
   Caip25CaveatType,
   Caip25EndowmentPermissionName,
-} from '../caip25permissions';
+} from '../caip25Permission';
+import type { ScopeString } from '../scope';
 import { mergeScopes } from '../scope';
 
-export async function CaipPermissionAdapterMiddleware(
-  request,
-  _response,
-  next,
-  end,
-  hooks,
+/**
+ * Middleware to handle CAIP-25 permission requests.
+ *
+ * @param request - The request object.
+ * @param _response - The response object.
+ * @param next - The next middleware function.
+ * @param end - The end function.
+ * @param hooks - The hooks object.
+ * @param hooks.getCaveat - Function to retrieve a caveat.
+ * @param hooks.getNetworkConfigurationByNetworkClientId - Function to retrieve a network configuration.
+ */
+export async function caipPermissionAdapterMiddleware(
+  request: JsonRpcRequest & {
+    networkClientId: string;
+    origin: string;
+  },
+  _response: unknown,
+  next: () => Promise<void>,
+  end: (error?: Error) => void,
+  hooks: {
+    getCaveat: (
+      ...args: unknown[]
+    ) => Caveat<typeof Caip25CaveatType, Caip25CaveatValue>;
+    getNetworkConfigurationByNetworkClientId: (
+      networkClientId: string,
+    ) => NetworkConfiguration;
+  },
 ) {
   const { networkClientId, method } = request;
 
@@ -31,7 +58,7 @@ export async function CaipPermissionAdapterMiddleware(
   const { chainId } =
     hooks.getNetworkConfigurationByNetworkClientId(networkClientId);
 
-  const scope = `eip155:${parseInt(chainId, 16)}`;
+  const scope: ScopeString = `eip155:${parseInt(chainId, 16)}`;
 
   const scopesObject = mergeScopes(
     caveat.value.requiredScopes,
diff --git a/packages/multichain/src/adapters/caip-permission-adapter-permittedChains.test.ts b/packages/multichain/src/adapters/caip-permission-adapter-permittedChains.test.ts
index e83562f7dcb..a7402078079 100644
--- a/packages/multichain/src/adapters/caip-permission-adapter-permittedChains.test.ts
+++ b/packages/multichain/src/adapters/caip-permission-adapter-permittedChains.test.ts
@@ -1,4 +1,4 @@
-import { Caip25CaveatValue } from '../caip25Permission';
+import type { Caip25CaveatValue } from '../caip25Permission';
 import { KnownNotifications, KnownRpcMethods } from '../scope';
 import {
   addPermittedEthChainId,
diff --git a/packages/multichain/src/adapters/caip-permission-adapter-permittedChains.ts b/packages/multichain/src/adapters/caip-permission-adapter-permittedChains.ts
index 39b2b86bea3..cfbbdedd298 100644
--- a/packages/multichain/src/adapters/caip-permission-adapter-permittedChains.ts
+++ b/packages/multichain/src/adapters/caip-permission-adapter-permittedChains.ts
@@ -1,13 +1,14 @@
-import { Hex, KnownCaipNamespace } from '@metamask/utils';
 import { toHex } from '@metamask/controller-utils';
-import { Caip25CaveatValue } from '../caip25Permission';
+import type { Hex } from '@metamask/utils';
+import { KnownCaipNamespace } from '@metamask/utils';
+
+import type { Caip25CaveatValue } from '../caip25Permission';
+import type { ScopesObject, ScopeString } from '../scope';
 import {
   KnownNotifications,
   KnownRpcMethods,
   mergeScopes,
   parseScopeString,
-  ScopesObject,
-  ScopeString,
 } from '../scope';
 
 export const getPermittedEthChainIds = (
diff --git a/packages/multichain/src/caip25Permission.test.ts b/packages/multichain/src/caip25Permission.test.ts
index cf63cf0a0c2..7e6d6f243d7 100644
--- a/packages/multichain/src/caip25Permission.test.ts
+++ b/packages/multichain/src/caip25Permission.test.ts
@@ -1,19 +1,20 @@
+import type { NonEmptyArray } from '@metamask/controller-utils';
+import type { CaveatConstraint } from '@metamask/permission-controller';
 import {
-  CaveatConstraint,
   CaveatMutatorOperation,
   PermissionType,
   SubjectType,
 } from '@metamask/permission-controller';
-import { NonEmptyArray } from '@metamask/controller-utils';
-import * as Scope from './scope';
+
+import type { Caip25CaveatValue } from './caip25Permission';
 import {
   Caip25CaveatType,
-  Caip25CaveatValue,
   caip25EndowmentBuilder,
   Caip25EndowmentPermissionName,
   Caip25CaveatMutatorFactories,
   removeScope,
 } from './caip25Permission';
+import * as Scope from './scope';
 
 jest.mock('./scope', () => ({
   validateAndFlattenScopes: jest.fn(),
@@ -655,34 +656,36 @@ describe('endowment:caip25', () => {
           },
         },
       });
-      validator({
-        caveats: [
-          {
-            type: Caip25CaveatType,
-            value: {
-              requiredScopes: {
-                'eip155:1': {
-                  methods: ['eth_chainId'],
-                  notifications: [],
-                  accounts: ['eip155:1:0xdead'],
+      expect(
+        validator({
+          caveats: [
+            {
+              type: Caip25CaveatType,
+              value: {
+                requiredScopes: {
+                  'eip155:1': {
+                    methods: ['eth_chainId'],
+                    notifications: [],
+                    accounts: ['eip155:1:0xdead'],
+                  },
                 },
-              },
-              optionalScopes: {
-                'eip155:5': {
-                  methods: [],
-                  notifications: [],
-                  accounts: ['eip155:5:0xbeef'],
+                optionalScopes: {
+                  'eip155:5': {
+                    methods: [],
+                    notifications: [],
+                    accounts: ['eip155:5:0xbeef'],
+                  },
                 },
+                isMultichainOrigin: true,
               },
-              isMultichainOrigin: true,
             },
-          },
-        ],
-        date: 1234,
-        id: '1',
-        invoker: 'test.com',
-        parentCapability: Caip25EndowmentPermissionName,
-      });
+          ],
+          date: 1234,
+          id: '1',
+          invoker: 'test.com',
+          parentCapability: Caip25EndowmentPermissionName,
+        }),
+      ).toBeUndefined();
     });
   });
 });
diff --git a/packages/multichain/src/caip25Permission.ts b/packages/multichain/src/caip25Permission.ts
index 35312b2e11f..d4cb66428cd 100644
--- a/packages/multichain/src/caip25Permission.ts
+++ b/packages/multichain/src/caip25Permission.ts
@@ -1,4 +1,4 @@
-import { strict as assert } from 'assert';
+import type { NetworkClientId } from '@metamask/network-controller';
 import type {
   PermissionSpecificationBuilder,
   EndowmentGetterParams,
@@ -11,22 +11,17 @@ import {
   PermissionType,
   SubjectType,
 } from '@metamask/permission-controller';
+import type { CaipAccountId, Json } from '@metamask/utils';
 import {
-  CaipAccountId,
-  Json,
   parseCaipAccountId,
   type Hex,
   type NonEmptyArray,
 } from '@metamask/utils';
-import { NetworkClientId } from '@metamask/network-controller';
+import { strict as assert } from 'assert';
 import { cloneDeep, isEqual } from 'lodash';
-import {
-  ExternalScopeString,
-  validateAndFlattenScopes,
-  ScopesObject,
-  ScopeObject,
-  assertScopesSupported,
-} from './scope';
+
+import type { ExternalScopeString, ScopesObject, ScopeObject } from './scope';
+import { validateAndFlattenScopes, assertScopesSupported } from './scope';
 
 export type Caip25CaveatValue = {
   requiredScopes: ScopesObject;
@@ -58,7 +53,7 @@ type Caip25EndowmentSpecification = ValidPermissionSpecification<{
  * `endowment:caip25` returns nothing atm;
  *
  * @param builderOptions - The specification builder options.
- * @param builderOptions.findNetworkClientIdByChainId
+ * @param builderOptions.findNetworkClientIdByChainId - The hook to find the networkClientId for a chainId.
  * @returns The specification for the `caip25` endowment.
  */
 const specificationBuilder: PermissionSpecificationBuilder<
@@ -145,9 +140,9 @@ export const Caip25CaveatMutatorFactories = {
   },
 };
 
-const reduceKeysHelper = <K extends string, V>(
-  acc: Record<K, V>,
-  [key, value]: [K, V],
+const reduceKeysHelper = <Key extends string, Value>(
+  acc: Record<Key, Value>,
+  [key, value]: [Key, Value],
 ) => {
   return {
     ...acc,
@@ -155,6 +150,12 @@ const reduceKeysHelper = <K extends string, V>(
   };
 };
 
+/**
+ * Removes the account from the scope object.
+ *
+ * @param targetAddress - The address to remove from the scope object.
+ * @returns A function that removes the account from the scope object.
+ */
 function removeAccountFilterFn(targetAddress: string) {
   return (account: CaipAccountId) => {
     const parsed = parseCaipAccountId(account);
@@ -162,6 +163,12 @@ function removeAccountFilterFn(targetAddress: string) {
   };
 }
 
+/**
+ * Removes the account from the scope object.
+ *
+ * @param targetAddress - The address to remove from the scope object.
+ * @param scopeObject - The scope object to remove the account from.
+ */
 function removeAccountOnScope(targetAddress: string, scopeObject: ScopeObject) {
   if (scopeObject.accounts) {
     scopeObject.accounts = scopeObject.accounts.filter(
@@ -170,6 +177,13 @@ function removeAccountOnScope(targetAddress: string, scopeObject: ScopeObject) {
   }
 }
 
+/**
+ * Removes the target account from the scope object.
+ *
+ * @param targetAddress - The address to remove from the scope object.
+ * @param existingScopes - The scope object to remove the account from.
+ * @returns The updated scope object.
+ */
 function removeAccount(
   targetAddress: string, // non caip-10 formatted address
   existingScopes: Caip25CaveatValue,
@@ -208,6 +222,7 @@ function removeAccount(
  *
  * @param targetScopeString - The scope that is being removed.
  * @param caip25CaveatValue - The CAIP-25 permission caveat value to remove the scope from.
+ * @returns The updated CAIP-25 permission caveat value.
  */
 export function removeScope(
   targetScopeString: ExternalScopeString,
diff --git a/packages/multichain/src/handlers/wallet-getSession.test.ts b/packages/multichain/src/handlers/wallet-getSession.test.ts
index bbbad820a20..ebee666967b 100644
--- a/packages/multichain/src/handlers/wallet-getSession.test.ts
+++ b/packages/multichain/src/handlers/wallet-getSession.test.ts
@@ -1,12 +1,17 @@
+import type { JsonRpcRequest } from '@metamask/utils';
+
 import {
   Caip25CaveatType,
   Caip25EndowmentPermissionName,
 } from '../caip25Permission';
 import { walletGetSessionHandler } from './wallet-getSession';
 
-const baseRequest = {
+const baseRequest: JsonRpcRequest & { origin: string } = {
   origin: 'http://test.com',
+  jsonrpc: '2.0' as const,
+  method: 'wallet_getSession',
   params: {},
+  id: 1,
 };
 
 const createMockedHandler = () => {
@@ -36,8 +41,14 @@ const createMockedHandler = () => {
       },
     },
   });
-  const response = {};
-  const handler = (request) =>
+  const response = {
+    result: {
+      sessionScopes: {},
+    },
+    id: 1,
+    jsonrpc: '2.0' as const,
+  };
+  const handler = (request: JsonRpcRequest & { origin: string }) =>
     walletGetSessionHandler(request, response, next, end, {
       getCaveat,
     });
diff --git a/packages/multichain/src/handlers/wallet-getSession.ts b/packages/multichain/src/handlers/wallet-getSession.ts
index 5bcefe07059..7f0032d00d7 100644
--- a/packages/multichain/src/handlers/wallet-getSession.ts
+++ b/packages/multichain/src/handlers/wallet-getSession.ts
@@ -1,15 +1,36 @@
+import type { Caveat } from '@metamask/permission-controller';
+import type { JsonRpcRequest, JsonRpcSuccess } from '@metamask/utils';
+
+import type { Caip25CaveatValue } from '../caip25Permission';
 import {
   Caip25CaveatType,
   Caip25EndowmentPermissionName,
 } from '../caip25Permission';
+import type { ScopesObject } from '../scope';
 import { mergeScopes } from '../scope';
 
+/**
+ * Handler for the `wallet_getSession` RPC method.
+ *
+ * @param request - The request object.
+ * @param response - The response object.
+ * @param _next - The next middleware function.
+ * @param end - The end function.
+ * @param hooks - The hooks object.
+ * @param hooks.getCaveat - Function to retrieve a caveat.
+ */
 export async function walletGetSessionHandler(
-  request,
-  response,
-  _next,
-  end,
-  hooks,
+  request: JsonRpcRequest & { origin: string },
+  response: JsonRpcSuccess<{ sessionScopes: ScopesObject }>,
+  _next: () => void,
+  end: () => void,
+  hooks: {
+    getCaveat: (
+      origin: string,
+      endowmentPermissionName: string,
+      caveatType: string,
+    ) => Caveat<typeof Caip25CaveatType, Caip25CaveatValue>;
+  },
 ) {
   let caveat;
   try {
diff --git a/packages/multichain/src/handlers/wallet-invokeMethod.test.ts b/packages/multichain/src/handlers/wallet-invokeMethod.test.ts
index 56d46d1c024..ebffb0ece8b 100644
--- a/packages/multichain/src/handlers/wallet-invokeMethod.test.ts
+++ b/packages/multichain/src/handlers/wallet-invokeMethod.test.ts
@@ -1,4 +1,6 @@
 import { providerErrors, rpcErrors } from '@metamask/rpc-errors';
+import type { JsonRpcRequest } from '@metamask/utils';
+
 import {
   Caip25CaveatType,
   Caip25EndowmentPermissionName,
@@ -6,7 +8,10 @@ import {
 import { walletInvokeMethodHandler } from './wallet-invokeMethod';
 
 const createMockedRequest = () => ({
+  jsonrpc: '2.0' as const,
+  id: 0,
   origin: 'http://test.com',
+  method: 'wallet_invokeMethod',
   params: {
     scope: 'eip155:1',
     request: {
@@ -54,8 +59,8 @@ const createMockedHandler = () => {
   const getSelectedNetworkClientId = jest
     .fn()
     .mockReturnValue('selectedNetworkClientId');
-  const handler = (request) =>
-    walletInvokeMethodHandler(request, {}, next, end, {
+  const handler = (request: JsonRpcRequest & { origin: string }) =>
+    walletInvokeMethodHandler(request, { jsonrpc: '2.0', id: 1 }, next, end, {
       getCaveat,
       findNetworkClientIdByChainId,
       getSelectedNetworkClientId,
@@ -180,6 +185,8 @@ describe('wallet_invokeMethod', () => {
 
       await handler(request);
       expect(request).toStrictEqual({
+        jsonrpc: '2.0' as const,
+        id: 0,
         scope: 'eip155:1',
         origin: 'http://test.com',
         networkClientId: 'mainnet',
@@ -248,6 +255,8 @@ describe('wallet_invokeMethod', () => {
       };
       await handler(walletRequest);
       expect(walletRequest).toStrictEqual({
+        jsonrpc: '2.0' as const,
+        id: 0,
         scope: 'wallet',
         origin: 'http://test.com',
         networkClientId: 'selectedNetworkClientId',
diff --git a/packages/multichain/src/handlers/wallet-invokeMethod.ts b/packages/multichain/src/handlers/wallet-invokeMethod.ts
index 1ca8ff5b1ea..55f60060831 100644
--- a/packages/multichain/src/handlers/wallet-invokeMethod.ts
+++ b/packages/multichain/src/handlers/wallet-invokeMethod.ts
@@ -1,19 +1,51 @@
-import { numberToHex } from '@metamask/utils';
+import type { Caveat } from '@metamask/permission-controller';
 import { providerErrors, rpcErrors } from '@metamask/rpc-errors';
+import type {
+  Json,
+  JsonRpcRequest,
+  PendingJsonRpcResponse,
+} from '@metamask/utils';
+import { numberToHex } from '@metamask/utils';
+
+import type { Caip25CaveatValue } from '../caip25Permission';
 import {
   Caip25CaveatType,
   Caip25EndowmentPermissionName,
 } from '../caip25Permission';
+import type { ScopeString } from '../scope';
 import { mergeScopes, parseScopeString } from '../scope';
 
+/**
+ * Handler for the `wallet_invokeMethod` RPC method.
+ *
+ * @param request - The request object.
+ * @param _response - The response object.
+ * @param next - The next middleware function.
+ * @param end - The end function.
+ * @param hooks - The hooks object.
+ * @param hooks.getCaveat - the hook for getting a caveat from a permission for an origin.
+ * @param hooks.findNetworkClientIdByChainId - the hook for finding the networkClientId for a chainId.
+ * @param hooks.getSelectedNetworkClientId - the hook for getting the current globally selected networkClientId.
+ */
 export async function walletInvokeMethodHandler(
-  request,
-  _response,
-  next,
-  end,
-  hooks,
+  request: JsonRpcRequest & { origin: string },
+  _response: PendingJsonRpcResponse<Json>,
+  next: () => void,
+  end: (error: Error) => void,
+  hooks: {
+    getCaveat: (
+      origin: string,
+      endowmentPermissionName: string,
+      caveatType: string,
+    ) => Caveat<typeof Caip25CaveatType, Caip25CaveatValue>;
+    findNetworkClientIdByChainId: (chainId: string) => string | undefined;
+    getSelectedNetworkClientId: () => string;
+  },
 ) {
-  const { scope, request: wrappedRequest } = request.params;
+  const { scope, request: wrappedRequest } = request.params as {
+    scope: ScopeString;
+    request: JsonRpcRequest;
+  };
 
   let caveat;
   try {
diff --git a/packages/multichain/src/handlers/wallet-revokeSession.test.ts b/packages/multichain/src/handlers/wallet-revokeSession.test.ts
index 6a6add80232..695d0eb4304 100644
--- a/packages/multichain/src/handlers/wallet-revokeSession.test.ts
+++ b/packages/multichain/src/handlers/wallet-revokeSession.test.ts
@@ -3,20 +3,29 @@ import {
   UnrecognizedSubjectError,
 } from '@metamask/permission-controller';
 import { rpcErrors } from '@metamask/rpc-errors';
+import type { JsonRpcRequest } from '@metamask/utils';
+
 import { Caip25EndowmentPermissionName } from '../caip25Permission';
 import { walletRevokeSessionHandler } from './wallet-revokeSession';
 
-const baseRequest = {
+const baseRequest: JsonRpcRequest & { origin: string } = {
   origin: 'http://test.com',
   params: {},
+  jsonrpc: '2.0' as const,
+  id: 1,
+  method: 'wallet_revokeSession',
 };
 
 const createMockedHandler = () => {
   const next = jest.fn();
   const end = jest.fn();
   const revokePermission = jest.fn();
-  const response = {};
-  const handler = (request) =>
+  const response = {
+    result: true,
+    id: 1,
+    jsonrpc: '2.0' as const,
+  };
+  const handler = (request: JsonRpcRequest & { origin: string }) =>
     walletRevokeSessionHandler(request, response, next, end, {
       revokePermission,
     });
@@ -44,21 +53,24 @@ describe('wallet_revokeSession', () => {
   it('returns true if the CAIP-25 endowment permission does not exist', async () => {
     const { handler, response, revokePermission } = createMockedHandler();
     revokePermission.mockImplementation(() => {
-      throw new PermissionDoesNotExistError();
+      throw new PermissionDoesNotExistError(
+        'foo.com',
+        Caip25EndowmentPermissionName,
+      );
     });
 
     await handler(baseRequest);
-    expect(response.result).toStrictEqual(true);
+    expect(response.result).toBe(true);
   });
 
   it('returns true if the subject does not exist', async () => {
     const { handler, response, revokePermission } = createMockedHandler();
     revokePermission.mockImplementation(() => {
-      throw new UnrecognizedSubjectError();
+      throw new UnrecognizedSubjectError('foo.com');
     });
 
     await handler(baseRequest);
-    expect(response.result).toStrictEqual(true);
+    expect(response.result).toBe(true);
   });
 
   it('throws an internal RPC error if something unexpected goes wrong with revoking the permission', async () => {
@@ -75,6 +87,6 @@ describe('wallet_revokeSession', () => {
     const { handler, response } = createMockedHandler();
 
     await handler(baseRequest);
-    expect(response.result).toStrictEqual(true);
+    expect(response.result).toBe(true);
   });
 });
diff --git a/packages/multichain/src/handlers/wallet-revokeSession.ts b/packages/multichain/src/handlers/wallet-revokeSession.ts
index d76994de901..1aec0b7245b 100644
--- a/packages/multichain/src/handlers/wallet-revokeSession.ts
+++ b/packages/multichain/src/handlers/wallet-revokeSession.ts
@@ -1,20 +1,33 @@
-import type { JsonRpcEngineNextCallback, JsonRpcEngineEndCallback } from '@metamask/json-rpc-engine';
+import type {
+  JsonRpcEngineNextCallback,
+  JsonRpcEngineEndCallback,
+} from '@metamask/json-rpc-engine';
 import {
   PermissionDoesNotExistError,
   UnrecognizedSubjectError,
-  PermissionController
 } from '@metamask/permission-controller';
 import { rpcErrors } from '@metamask/rpc-errors';
+import type { JsonRpcSuccess, Json, JsonRpcRequest } from '@metamask/utils';
+
 import { Caip25EndowmentPermissionName } from '../caip25Permission';
-import { JsonRpcRequest, JsonRpcResponse } from '@metamask/utils';
 
+/**
+ * Handles the `wallet_revokeSession` RPC method.
+ *
+ * @param request - The JSON-RPC request object.
+ * @param response - The JSON-RPC response object.
+ * @param _next - The next middleware function.
+ * @param end - The end callback function.
+ * @param hooks - The hooks object.
+ * @param hooks.revokePermission - The revokePermission function.
+ */
 export async function walletRevokeSessionHandler(
-  request: JsonRpcRequest<Params>,
-  response: JsonRpcResponse<true>,
+  request: JsonRpcRequest & { origin: string },
+  response: JsonRpcSuccess<Json>,
   _next: JsonRpcEngineNextCallback,
   end: JsonRpcEngineEndCallback,
   hooks: {
-    revokePermission: PermissionController['revokePermission']
+    revokePermission: (origin: string, permissionName: string) => void;
   },
 ) {
   try {
diff --git a/packages/multichain/src/middlewares/MultichainMiddlewareManager.test.ts b/packages/multichain/src/middlewares/MultichainMiddlewareManager.test.ts
index b00cd7ab4ed..c6097529946 100644
--- a/packages/multichain/src/middlewares/MultichainMiddlewareManager.test.ts
+++ b/packages/multichain/src/middlewares/MultichainMiddlewareManager.test.ts
@@ -1,7 +1,5 @@
-import { JsonRpcRequest } from '@metamask/utils';
-import MultichainMiddlewareManager, {
-  ExtendedJsonRpcMiddleware,
-} from './MultichainMiddlewareManager';
+import type { ExtendedJsonRpcMiddleware } from './MultichainMiddlewareManager';
+import MultichainMiddlewareManager from './MultichainMiddlewareManager';
 
 const scope = 'eip155:1';
 const origin = 'example.com';
@@ -28,13 +26,13 @@ describe('MultichainMiddlewareManager', () => {
     const endSpy = jest.fn();
 
     middleware(
-      { scope } as unknown as JsonRpcRequest,
+      { jsonrpc: '2.0' as const, id: 0, method: 'method', scope },
       { jsonrpc: '2.0', id: 0 },
       nextSpy,
       endSpy,
     );
     expect(middlewareSpy).toHaveBeenCalledWith(
-      { scope } as unknown as JsonRpcRequest,
+      { jsonrpc: '2.0' as const, id: 0, method: 'method', scope },
       { jsonrpc: '2.0', id: 0 },
       nextSpy,
       endSpy,
@@ -43,7 +41,7 @@ describe('MultichainMiddlewareManager', () => {
     expect(endSpy).not.toHaveBeenCalled();
   });
 
-  it('should remove middleware by origin and tabId when the multiplexing middleware is destroyed', () => {
+  it('should remove middleware by origin and tabId when the multiplexing middleware is destroyed', async () => {
     const multichainMiddlewareManager = new MultichainMiddlewareManager();
     const middlewareSpy = jest.fn() as unknown as ExtendedJsonRpcMiddleware;
     multichainMiddlewareManager.addMiddleware({
@@ -59,13 +57,13 @@ describe('MultichainMiddlewareManager', () => {
         123,
       );
 
-    middleware.destroy?.();
+    await middleware.destroy?.();
 
     const nextSpy = jest.fn();
     const endSpy = jest.fn();
 
     middleware(
-      { scope } as unknown as JsonRpcRequest,
+      { jsonrpc: '2.0' as const, id: 0, method: 'method', scope },
       { jsonrpc: '2.0', id: 0 },
       nextSpy,
       endSpy,
@@ -97,7 +95,7 @@ describe('MultichainMiddlewareManager', () => {
     const endSpy = jest.fn();
 
     middleware(
-      { scope } as unknown as JsonRpcRequest,
+      { jsonrpc: '2.0' as const, id: 0, method: 'method', scope },
       { jsonrpc: '2.0', id: 0 },
       nextSpy,
       endSpy,
@@ -129,7 +127,7 @@ describe('MultichainMiddlewareManager', () => {
     const endSpy = jest.fn();
 
     middleware(
-      { scope } as unknown as JsonRpcRequest,
+      { jsonrpc: '2.0' as const, id: 0, method: 'method', scope },
       { jsonrpc: '2.0', id: 0 },
       nextSpy,
       endSpy,
@@ -161,7 +159,7 @@ describe('MultichainMiddlewareManager', () => {
     const endSpy = jest.fn();
 
     middleware(
-      { scope } as unknown as JsonRpcRequest,
+      { jsonrpc: '2.0' as const, id: 0, method: 'method', scope },
       { jsonrpc: '2.0', id: 0 },
       nextSpy,
       endSpy,
diff --git a/packages/multichain/src/middlewares/MultichainMiddlewareManager.ts b/packages/multichain/src/middlewares/MultichainMiddlewareManager.ts
index e4c2663099b..205c6a67518 100644
--- a/packages/multichain/src/middlewares/MultichainMiddlewareManager.ts
+++ b/packages/multichain/src/middlewares/MultichainMiddlewareManager.ts
@@ -1,11 +1,23 @@
-import { JsonRpcMiddleware } from '@metamask/json-rpc-engine';
-import { ExternalScopeString } from '../scope';
-import { Json, JsonRpcParams } from '@metamask/utils';
-
-// Extend JsonRpcMiddleware to include the destroy method
-// this was introduced in 7.0.0 of json-rpc-engine: https://github.com/MetaMask/json-rpc-engine/blob/v7.0.0/src/JsonRpcEngine.ts#L29-L40
-export type ExtendedJsonRpcMiddleware = JsonRpcMiddleware<JsonRpcParams, Json> & {
-  destroy?: () => void;
+import type {
+  JsonRpcEngineEndCallback,
+  JsonRpcEngineNextCallback,
+} from '@metamask/json-rpc-engine';
+import type {
+  Json,
+  JsonRpcRequest,
+  PendingJsonRpcResponse,
+} from '@metamask/utils';
+
+import type { ExternalScopeString } from '../scope';
+
+export type ExtendedJsonRpcMiddleware = {
+  (
+    req: JsonRpcRequest & { scope: string },
+    res: PendingJsonRpcResponse<Json>,
+    next: JsonRpcEngineNextCallback,
+    end: JsonRpcEngineEndCallback,
+  ): void;
+  destroy?: () => void | Promise<void>;
 };
 
 type MiddlewareKey = {
@@ -57,7 +69,10 @@ export default class MultichainMiddlewareManager {
       return;
     }
 
-    existingMiddlewareEntry.middleware.destroy?.();
+    // When the destroy function on the middleware is async,
+    // we don't need to wait for it complete
+    // eslint-disable-next-line no-void
+    void existingMiddlewareEntry.middleware.destroy?.();
 
     this.#removeMiddlewareEntry(middlewareKey);
   }
@@ -97,10 +112,7 @@ export default class MultichainMiddlewareManager {
     tabId?: number,
   ) {
     const middleware: ExtendedJsonRpcMiddleware = (req, res, next, end) => {
-      const r = req as unknown as {
-        scope: string;
-      };
-      const { scope } = r;
+      const { scope } = req;
       const middlewareEntry = this.#getMiddlewareEntry({
         scope,
         origin,
@@ -110,8 +122,9 @@ export default class MultichainMiddlewareManager {
       if (middlewareEntry) {
         middlewareEntry.middleware(req, res, next, end);
       } else {
-        next();
+        return next();
       }
+      return undefined;
     };
     middleware.destroy = this.removeMiddlewareByOriginAndTabId.bind(
       this,
diff --git a/packages/multichain/src/middlewares/MultichainSubscriptionManager.test.ts b/packages/multichain/src/middlewares/MultichainSubscriptionManager.test.ts
index 86fda171cec..c951b711af7 100644
--- a/packages/multichain/src/middlewares/MultichainSubscriptionManager.test.ts
+++ b/packages/multichain/src/middlewares/MultichainSubscriptionManager.test.ts
@@ -1,4 +1,5 @@
 import createSubscriptionManager from '@metamask/eth-json-rpc-filters/subscriptionManager';
+
 import MultichainSubscriptionManager from './MultichainSubscriptionManager';
 
 jest.mock('@metamask/eth-json-rpc-filters/subscriptionManager', () =>
@@ -63,7 +64,7 @@ describe('MultichainSubscriptionManager', () => {
   });
 
   it('should subscribe to a scope, origin, and tabId', () => {
-    const { multichainSubscriptionManager} =
+    const { multichainSubscriptionManager } =
       createMultichainSubscriptionManager();
     multichainSubscriptionManager.subscribe({ scope, origin, tabId });
     const onNotificationSpy = jest.fn();
@@ -83,7 +84,7 @@ describe('MultichainSubscriptionManager', () => {
   });
 
   it('should unsubscribe from a scope', () => {
-    const { multichainSubscriptionManager} =
+    const { multichainSubscriptionManager } =
       createMultichainSubscriptionManager();
     multichainSubscriptionManager.subscribe({ scope, origin, tabId });
     multichainSubscriptionManager.unsubscribeByScope(scope);
@@ -92,7 +93,7 @@ describe('MultichainSubscriptionManager', () => {
   });
 
   it('should unsubscribe from a scope and origin', () => {
-    const { multichainSubscriptionManager} =
+    const { multichainSubscriptionManager } =
       createMultichainSubscriptionManager();
     multichainSubscriptionManager.subscribe({ scope, origin, tabId });
     multichainSubscriptionManager.unsubscribeByScopeAndOrigin(scope, origin);
@@ -105,7 +106,7 @@ describe('MultichainSubscriptionManager', () => {
   });
 
   it('should unsubscribe from a origin and tabId', () => {
-    const { multichainSubscriptionManager} =
+    const { multichainSubscriptionManager } =
       createMultichainSubscriptionManager();
     multichainSubscriptionManager.subscribe({ scope, origin, tabId });
     multichainSubscriptionManager.unsubscribeByOriginAndTabId(origin, tabId);
diff --git a/packages/multichain/src/middlewares/MultichainSubscriptionManager.ts b/packages/multichain/src/middlewares/MultichainSubscriptionManager.ts
index 668aa431aa6..7ffb75b7230 100644
--- a/packages/multichain/src/middlewares/MultichainSubscriptionManager.ts
+++ b/packages/multichain/src/middlewares/MultichainSubscriptionManager.ts
@@ -1,9 +1,11 @@
-import EventEmitter from 'events';
-import { NetworkController } from '@metamask/network-controller';
-import SafeEventEmitter from '@metamask/safe-event-emitter';
-import { CaipChainId, Hex, parseCaipChainId } from '@metamask/utils';
 import { toHex } from '@metamask/controller-utils';
-import { ExternalScopeString } from '../scope';
+import type { NetworkController } from '@metamask/network-controller';
+import SafeEventEmitter from '@metamask/safe-event-emitter';
+import type { CaipChainId, Hex } from '@metamask/utils';
+import { parseCaipChainId } from '@metamask/utils';
+import type EventEmitter from 'events';
+
+import type { ExternalScopeString } from '../scope';
 
 export type SubscriptionManager = {
   events: EventEmitter;
diff --git a/packages/multichain/src/middlewares/multichainMethodCallValidator.ts b/packages/multichain/src/middlewares/multichainMethodCallValidator.ts
index 7c68c56b916..a57ac7835a6 100644
--- a/packages/multichain/src/middlewares/multichainMethodCallValidator.ts
+++ b/packages/multichain/src/middlewares/multichainMethodCallValidator.ts
@@ -1,21 +1,22 @@
 import { MultiChainOpenRPCDocument } from '@metamask/api-specs';
+import type { JsonRpcMiddleware } from '@metamask/json-rpc-engine';
 import { rpcErrors } from '@metamask/rpc-errors';
-import {
+import { isObject } from '@metamask/utils';
+import type {
+  Json,
   JsonRpcError,
   JsonRpcParams,
   JsonRpcRequest,
-  isObject,
 } from '@metamask/utils';
-import {
+import type {
   ContentDescriptorObject,
   MethodObject,
   OpenrpcDocument,
 } from '@open-rpc/meta-schema';
 import dereferenceDocument from '@open-rpc/schema-utils-js/build/dereference-document';
 import { makeCustomResolver } from '@open-rpc/schema-utils-js/build/parse-open-rpc-document';
-import { JsonRpcMiddleware } from '@metamask/json-rpc-engine';
-import { Json } from '@metamask/utils';
-import { Schema, ValidationError, Validator } from 'jsonschema';
+import type { Schema, ValidationError } from 'jsonschema';
+import { Validator } from 'jsonschema';
 
 const transformError = (
   error: ValidationError,
@@ -88,6 +89,7 @@ export const multichainMethodCallValidatorMiddleware: JsonRpcMiddleware<
   JsonRpcRequest,
   Json
 > = function (request, _response, next, end) {
+  // eslint-disable-next-line @typescript-eslint/no-floating-promises
   multichainMethodCallValidator(request.method, request.params).then(
     (errors) => {
       if (errors) {
diff --git a/packages/multichain/src/scope/assert.test.ts b/packages/multichain/src/scope/assert.test.ts
index 919b6e6a388..75485352bac 100644
--- a/packages/multichain/src/scope/assert.test.ts
+++ b/packages/multichain/src/scope/assert.test.ts
@@ -1,6 +1,7 @@
 import { JsonRpcError } from '@metamask/rpc-errors';
+
 import { assertScopeSupported, assertScopesSupported } from './assert';
-import { ScopeObject } from './scope';
+import type { ScopeObject } from './scope';
 import * as Supported from './supported';
 
 jest.mock('./supported', () => ({
@@ -133,10 +134,7 @@ describe('Scope Assert', () => {
             },
           );
         }).toThrow(
-          new JsonRpcError(
-            5102,
-            'Requested notifications are not supported',
-          ),
+          new JsonRpcError(5102, 'Requested notifications are not supported'),
         );
       });
 
@@ -165,12 +163,14 @@ describe('Scope Assert', () => {
     const isChainIdSupported = jest.fn();
 
     it('does not throw an error if no scopes are defined', () => {
-      assertScopesSupported(
-        {},
-        {
-          isChainIdSupported,
-        },
-      );
+      expect(
+        assertScopesSupported(
+          {},
+          {
+            isChainIdSupported,
+          },
+        ),
+      ).toBeUndefined();
     });
 
     it('throws an error if any scope is invalid', () => {
@@ -185,9 +185,7 @@ describe('Scope Assert', () => {
             isChainIdSupported,
           },
         );
-      }).toThrow(
-        new JsonRpcError(5100, 'Requested chains are not supported'),
-      );
+      }).toThrow(new JsonRpcError(5100, 'Requested chains are not supported'));
     });
 
     it('does not throw an error if all scopes are valid', () => {
diff --git a/packages/multichain/src/scope/assert.ts b/packages/multichain/src/scope/assert.ts
index 2724ecd2214..ea436fb9091 100644
--- a/packages/multichain/src/scope/assert.ts
+++ b/packages/multichain/src/scope/assert.ts
@@ -1,11 +1,12 @@
-import { Hex } from '@metamask/utils';
 import { JsonRpcError } from '@metamask/rpc-errors';
+import type { Hex } from '@metamask/utils';
+
+import type { ScopeObject, ScopesObject } from './scope';
 import {
   isSupportedMethod,
   isSupportedNotification,
   isSupportedScopeString,
 } from './supported';
-import { ScopeObject, ScopesObject } from './scope';
 
 export const assertScopeSupported = (
   scopeString: string,
@@ -50,10 +51,7 @@ export const assertScopeSupported = (
     // When provider does not recognize one or more requested notification(s)
     //   code = 5202
     //   message = "Unknown notification(s) requested"
-    throw new JsonRpcError(
-      5102,
-      'Requested notifications are not supported',
-    );
+    throw new JsonRpcError(5102, 'Requested notifications are not supported');
   }
 };
 
diff --git a/packages/multichain/src/scope/authorization.test.ts b/packages/multichain/src/scope/authorization.test.ts
index 69e57dc32ca..318718133d3 100644
--- a/packages/multichain/src/scope/authorization.test.ts
+++ b/packages/multichain/src/scope/authorization.test.ts
@@ -1,11 +1,8 @@
-import * as Validation from './validation';
-import * as Transform from './transform';
+import { bucketScopes, validateAndFlattenScopes } from './authorization';
 import * as Filter from './filter';
-import {
-  bucketScopes,
-  validateAndFlattenScopes,
-} from './authorization';
-import { ExternalScopeObject } from './scope';
+import type { ExternalScopeObject } from './scope';
+import * as Transform from './transform';
+import * as Validation from './validation';
 
 jest.mock('./validation', () => ({
   validateScopes: jest.fn(),
diff --git a/packages/multichain/src/scope/authorization.ts b/packages/multichain/src/scope/authorization.ts
index b6c83cb1cf6..3b4f5e06199 100644
--- a/packages/multichain/src/scope/authorization.ts
+++ b/packages/multichain/src/scope/authorization.ts
@@ -1,8 +1,9 @@
-import { validateScopes } from './validation';
-import { ExternalScopesObject, ScopesObject, ScopedProperties } from './scope';
-import { flattenMergeScopes } from './transform';
+import type { Hex } from '@metamask/utils';
+
 import { bucketScopesBySupport } from './filter';
-import { Hex } from '@metamask/utils';
+import type { ExternalScopesObject, ScopesObject } from './scope';
+import { flattenMergeScopes } from './transform';
+import { validateScopes } from './validation';
 
 export type Caip25Authorization =
   | {
diff --git a/packages/multichain/src/scope/filter.ts b/packages/multichain/src/scope/filter.ts
index 06b9795c497..ab5e889af17 100644
--- a/packages/multichain/src/scope/filter.ts
+++ b/packages/multichain/src/scope/filter.ts
@@ -1,6 +1,7 @@
-import { CaipChainId, Hex } from '@metamask/utils';
-import { ScopesObject } from './scope';
+import type { CaipChainId, Hex } from '@metamask/utils';
+
 import { assertScopeSupported } from './assert';
+import type { ScopesObject } from './scope';
 
 export const bucketScopesBySupport = (
   scopes: ScopesObject,
diff --git a/packages/multichain/src/scope/scope.test.ts b/packages/multichain/src/scope/scope.test.ts
index 2441c41c348..d3a58b3221a 100644
--- a/packages/multichain/src/scope/scope.test.ts
+++ b/packages/multichain/src/scope/scope.test.ts
@@ -6,7 +6,7 @@ describe('Scope', () => {
       expect(parseScopeString('abc')).toStrictEqual({ namespace: 'abc' });
     });
 
-    it('returns the namespace and reference if scopeString is a CAIP chain ID ', () => {
+    it('returns the namespace and reference if scopeString is a CAIP chain ID', () => {
       expect(parseScopeString('abc:foo')).toStrictEqual({
         namespace: 'abc',
         reference: 'foo',
diff --git a/packages/multichain/src/scope/scope.ts b/packages/multichain/src/scope/scope.ts
index ae452ee6536..c899fa8a40e 100644
--- a/packages/multichain/src/scope/scope.ts
+++ b/packages/multichain/src/scope/scope.ts
@@ -1,18 +1,20 @@
 import MetaMaskOpenRPCDocument from '@metamask/api-specs';
-import {
+import type {
   CaipChainId,
   CaipReference,
   CaipAccountId,
+  KnownCaipNamespace,
+  CaipNamespace,
+} from '@metamask/utils';
+import {
   isCaipNamespace,
   isCaipChainId,
   parseCaipChainId,
-  KnownCaipNamespace,
-  CaipNamespace,
 } from '@metamask/utils';
 
-export type NonWalletKnownCaipNamespace = Exclude<
+export type NonWalletKnownCaipNamespace = Extract<
   KnownCaipNamespace,
-  KnownCaipNamespace.Wallet
+  KnownCaipNamespace.Eip155
 >;
 
 export const KnownWalletRpcMethods: string[] = [
@@ -22,7 +24,7 @@ export const KnownWalletRpcMethods: string[] = [
 const WalletEip155Methods = ['wallet_addEthereumChain'];
 
 const Eip155Methods = MetaMaskOpenRPCDocument.methods
-  .map(({ name }: { name: string}) => name)
+  .map(({ name }: { name: string }) => name)
   .filter((method: string) => !WalletEip155Methods.includes(method))
   .filter((method: string) => !KnownWalletRpcMethods.includes(method));
 
diff --git a/packages/multichain/src/scope/supported.test.ts b/packages/multichain/src/scope/supported.test.ts
index 30b85491079..b8146ebd157 100644
--- a/packages/multichain/src/scope/supported.test.ts
+++ b/packages/multichain/src/scope/supported.test.ts
@@ -1,14 +1,14 @@
-import {
-  isSupportedMethod,
-  isSupportedNotification,
-  isSupportedScopeString,
-} from './supported';
 import {
   KnownNotifications,
   KnownRpcMethods,
   KnownWalletNamespaceRpcMethods,
   KnownWalletRpcMethods,
 } from './scope';
+import {
+  isSupportedMethod,
+  isSupportedNotification,
+  isSupportedScopeString,
+} from './supported';
 
 describe('Scope Support', () => {
   describe('isSupportedNotification', () => {
@@ -16,18 +16,14 @@ describe('Scope Support', () => {
       'returns true for each %s scope method',
       (scopeString: string, notifications: string[]) => {
         notifications.forEach((notification) => {
-          expect(
-            isSupportedNotification(scopeString, notification),
-          ).toStrictEqual(true);
+          expect(isSupportedNotification(scopeString, notification)).toBe(true);
         });
       },
     );
 
     it('returns false otherwise', () => {
-      expect(isSupportedNotification('eip155', 'anything else')).toStrictEqual(
-        false,
-      );
-      expect(isSupportedNotification('', '')).toStrictEqual(false);
+      expect(isSupportedNotification('eip155', 'anything else')).toBe(false);
+      expect(isSupportedNotification('', '')).toBe(false);
     });
   });
 
@@ -36,14 +32,14 @@ describe('Scope Support', () => {
       'returns true for each %s scoped method',
       (scopeString: string, methods: string[]) => {
         methods.forEach((method) => {
-          expect(isSupportedMethod(scopeString, method)).toStrictEqual(true);
+          expect(isSupportedMethod(scopeString, method)).toBe(true);
         });
       },
     );
 
     it('returns true for each wallet scoped method', () => {
       KnownWalletRpcMethods.forEach((method) => {
-        expect(isSupportedMethod('wallet', method)).toStrictEqual(true);
+        expect(isSupportedMethod('wallet', method)).toBe(true);
       });
     });
 
@@ -51,46 +47,42 @@ describe('Scope Support', () => {
       'returns true for each wallet:%s scoped method',
       (scopeString: string, methods: string[]) => {
         methods.forEach((method) => {
-          expect(
-            isSupportedMethod(`wallet:${scopeString}`, method),
-          ).toStrictEqual(true);
+          expect(isSupportedMethod(`wallet:${scopeString}`, method)).toBe(true);
         });
       },
     );
 
     it('returns false otherwise', () => {
-      expect(isSupportedMethod('eip155', 'anything else')).toStrictEqual(false);
-      expect(isSupportedMethod('', '')).toStrictEqual(false);
+      expect(isSupportedMethod('eip155', 'anything else')).toBe(false);
+      expect(isSupportedMethod('', '')).toBe(false);
     });
   });
 
   describe('isSupportedScopeString', () => {
     it('returns true for the wallet namespace', () => {
-      expect(isSupportedScopeString('wallet', jest.fn())).toStrictEqual(true);
+      expect(isSupportedScopeString('wallet', jest.fn())).toBe(true);
     });
 
     it('returns false for the wallet namespace when a reference is included', () => {
-      expect(isSupportedScopeString('wallet:someref', jest.fn())).toStrictEqual(
-        false,
-      );
+      expect(isSupportedScopeString('wallet:someref', jest.fn())).toBe(false);
     });
 
     it('returns true for the ethereum namespace', () => {
-      expect(isSupportedScopeString('eip155', jest.fn())).toStrictEqual(true);
+      expect(isSupportedScopeString('eip155', jest.fn())).toBe(true);
     });
 
     it('returns true for the ethereum namespace when a network client exists for the reference', () => {
       const isChainIdSupportedMock = jest.fn().mockReturnValue(true);
-      expect(
-        isSupportedScopeString('eip155:1', isChainIdSupportedMock),
-      ).toStrictEqual(true);
+      expect(isSupportedScopeString('eip155:1', isChainIdSupportedMock)).toBe(
+        true,
+      );
     });
 
     it('returns false for the ethereum namespace when a network client does not exist for the reference', () => {
       const isChainIdSupportedMock = jest.fn().mockReturnValue(false);
-      expect(
-        isSupportedScopeString('eip155:1', isChainIdSupportedMock),
-      ).toStrictEqual(false);
+      expect(isSupportedScopeString('eip155:1', isChainIdSupportedMock)).toBe(
+        false,
+      );
     });
   });
 });
diff --git a/packages/multichain/src/scope/supported.ts b/packages/multichain/src/scope/supported.ts
index 9ca98be6e23..80ceb961f4d 100644
--- a/packages/multichain/src/scope/supported.ts
+++ b/packages/multichain/src/scope/supported.ts
@@ -1,29 +1,31 @@
+import { toHex } from '@metamask/controller-utils';
+import type { CaipAccountId, Hex } from '@metamask/utils';
 import {
-  CaipAccountId,
-  Hex,
   isCaipChainId,
   isCaipNamespace,
   KnownCaipNamespace,
   parseCaipAccountId,
   parseCaipChainId,
 } from '@metamask/utils';
-import { toHex } from '@metamask/controller-utils';
-import { InternalAccount } from '@metamask/keyring-api';
+
+import type { NonWalletKnownCaipNamespace, ExternalScopeString } from './scope';
 import {
   KnownNotifications,
   KnownRpcMethods,
   KnownWalletNamespaceRpcMethods,
   KnownWalletRpcMethods,
-  NonWalletKnownCaipNamespace,
   parseScopeString,
-  ExternalScopeString,
 } from './scope';
 
 // TODO Maybe this gets DRY'ed into utils?.. It's used in TokenDetectionController too
-function isEqualCaseInsensitive(
-  value1: string,
-  value2: string,
-): boolean {
+/**
+ * Checks if two strings are equal, ignoring case.
+ *
+ * @param value1 - The first string to compare.
+ * @param value2 - The second string to compare.
+ * @returns `true` if the strings are equal, ignoring case; otherwise, `false`.
+ */
+function isEqualCaseInsensitive(value1: string, value2: string): boolean {
   if (typeof value1 !== 'string' || typeof value2 !== 'string') {
     return false;
   }
@@ -68,7 +70,7 @@ export const isSupportedScopeString = (
 
 export const isSupportedAccount = (
   account: CaipAccountId,
-  getInternalAccounts: () => InternalAccount[],
+  getInternalAccounts: () => { type: string; address: string }[],
 ) => {
   const {
     address,
diff --git a/packages/multichain/src/scope/transform.test.ts b/packages/multichain/src/scope/transform.test.ts
index df0b529822f..d092735eb67 100644
--- a/packages/multichain/src/scope/transform.test.ts
+++ b/packages/multichain/src/scope/transform.test.ts
@@ -1,4 +1,4 @@
-import { ExternalScopeObject } from './scope';
+import type { ExternalScopeObject } from './scope';
 import {
   flattenScope,
   mergeScopes,
diff --git a/packages/multichain/src/scope/transform.ts b/packages/multichain/src/scope/transform.ts
index a31faf2d34c..097ad725d89 100644
--- a/packages/multichain/src/scope/transform.ts
+++ b/packages/multichain/src/scope/transform.ts
@@ -1,16 +1,23 @@
-import { CaipReference } from '@metamask/utils';
+import type { CaipReference } from '@metamask/utils';
 import { cloneDeep } from 'lodash';
-import {
+
+import type {
   ExternalScopeObject,
   ExternalScopesObject,
   ScopeString,
   ScopeObject,
   ScopesObject,
-  parseScopeString,
 } from './scope';
+import { parseScopeString } from './scope';
 
-// DRY THIS
-function unique<T>(list: T[]): T[] {
+// TODO: DRY THIS
+/**
+ * Returns a list of unique items
+ *
+ * @param list - The list of items to filter
+ * @returns A list of unique items
+ */
+function unique<Value>(list: Value[]): Value[] {
   return Array.from(new Set(list));
 }
 
@@ -32,7 +39,7 @@ export const flattenScope = (
   const { namespace, reference } = parseScopeString(scopeString);
 
   // Scope is already a CAIP-2 ID and has no references to flatten
-  if (reference || !references) {
+  if (!namespace || reference || !references) {
     return { [scopeString]: scopeObject };
   }
 
diff --git a/packages/multichain/src/scope/validation.test.ts b/packages/multichain/src/scope/validation.test.ts
index 507f24b328b..f4f4ae63e34 100644
--- a/packages/multichain/src/scope/validation.test.ts
+++ b/packages/multichain/src/scope/validation.test.ts
@@ -1,8 +1,5 @@
-import { ExternalScopeObject } from './scope';
-import {
-  isValidScope,
-  validateScopes,
-} from './validation';
+import type { ExternalScopeObject } from './scope';
+import { isValidScope, validateScopes } from './validation';
 
 const validScopeString = 'eip155:1';
 const validScopeObject: ExternalScopeObject = {
@@ -128,7 +125,9 @@ describe('Scope Validation', () => {
         scopeString: string,
         scopeObject: unknown,
       ) => {
-        expect(isValidScope(scopeString, scopeObject as ExternalScopeObject)).toStrictEqual(expected);
+        expect(
+          isValidScope(scopeString, scopeObject as ExternalScopeObject),
+        ).toStrictEqual(expected);
       },
     );
   });
@@ -140,16 +139,20 @@ describe('Scope Validation', () => {
     };
 
     it('does not throw an error if required scopes are defined but none are valid', () => {
-      validateScopes(
-        { 'eip155:1': {} as unknown as ExternalScopeObject },
-        undefined,
-      );
+      expect(
+        validateScopes(
+          { 'eip155:1': {} as unknown as ExternalScopeObject },
+          undefined,
+        ),
+      ).toStrictEqual({ validRequiredScopes: {}, validOptionalScopes: {} });
     });
 
     it('does not throw an error if optional scopes are defined but none are valid', () => {
-      validateScopes(undefined, {
-        'eip155:1': {} as unknown as ExternalScopeObject,
-      });
+      expect(
+        validateScopes(undefined, {
+          'eip155:1': {} as unknown as ExternalScopeObject,
+        }),
+      ).toStrictEqual({ validRequiredScopes: {}, validOptionalScopes: {} });
     });
 
     it('returns the valid required and optional scopes', () => {
diff --git a/packages/multichain/src/scope/validation.ts b/packages/multichain/src/scope/validation.ts
index 8a5ab1a1cdf..69bc3e1bb9c 100644
--- a/packages/multichain/src/scope/validation.ts
+++ b/packages/multichain/src/scope/validation.ts
@@ -1,10 +1,11 @@
 import { isCaipReference } from '@metamask/utils';
-import {
+
+import type {
   ExternalScopeString,
-  parseScopeString,
   ExternalScopeObject,
   ExternalScopesObject,
 } from './scope';
+import { parseScopeString } from './scope';
 
 export const isValidScope = (
   scopeString: ExternalScopeString,
diff --git a/packages/multichain/tsconfig.build.json b/packages/multichain/tsconfig.build.json
index 02a0eea03fe..f2108df2764 100644
--- a/packages/multichain/tsconfig.build.json
+++ b/packages/multichain/tsconfig.build.json
@@ -3,8 +3,16 @@
   "compilerOptions": {
     "baseUrl": "./",
     "outDir": "./dist",
-    "rootDir": "./src"
+    "rootDir": "./src",
+    "resolveJsonModule": true
   },
-  "references": [],
+  "references": [
+    {
+      "path": "../network-controller/tsconfig.build.json"
+    },
+    {
+      "path": "../permission-controller/tsconfig.build.json"
+    }
+  ],
   "include": ["../../types", "./src"]
 }
diff --git a/yarn.lock b/yarn.lock
index b43e7ce698f..88a64433d35 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -3089,16 +3089,20 @@ __metadata:
   dependencies:
     "@metamask/api-specs": "npm:^0.10.12"
     "@metamask/auto-changelog": "npm:^3.4.4"
+    "@metamask/controller-utils": "npm:^11.3.0"
     "@metamask/eth-json-rpc-filters": "npm:^7.0.0"
     "@metamask/json-rpc-engine": "npm:^9.0.3"
     "@metamask/network-controller": "npm:^21.0.1"
     "@metamask/permission-controller": "npm:^11.0.2"
     "@metamask/rpc-errors": "npm:^6.3.1"
+    "@metamask/safe-event-emitter": "npm:^3.0.0"
+    "@metamask/utils": "npm:^9.1.0"
     "@open-rpc/meta-schema": "npm:^1.14.6"
     "@open-rpc/schema-utils-js": "npm:^2.0.5"
     "@types/jest": "npm:^27.4.1"
     deepmerge: "npm:^4.2.2"
     jest: "npm:^27.5.1"
+    jsonschema: "npm:^1.2.4"
     lodash: "npm:^4.17.21"
     ts-jest: "npm:^27.1.4"
     typedoc: "npm:^0.24.8"