MetaMask · ulissesferreira · Sep 2, 2026 · Sep 2, 2026 · ulissesferreira · Sep 2, 2026
@@ -114,6 +114,7 @@ jobs:
       matrix:
         node-version: [24.x]
         script:
+          - lint:tsc
           - lint:eslint
           - lint:misc:check
           - constraints

@@ -46,13 +46,14 @@ The monorepo uses a hierarchical configuration approach for different tools. For
 
 #### TypeScript
 
-- `tsconfig.base.json` defines shared development-specific TypeScript settings for all other config files.
-- `tsconfig.build.json` defines shared build-specific TypeScript settings for all other config files.
-- `tsconfig.packages.json` defines shared development-specific TypeScript settings for all directories in `packages/`.
-- `tsconfig.packages.build.json` defines shared build-specific TypeScript settings for all directories in `packages/`.
+- `tsconfig.base.json` defines shared compiler defaults for all other config files.
+- `tsconfig.json` defines TypeScript settings for repository scripts and editor features.
+- `tsconfig.packages.json` defines shared source, editor, and type-checking settings for all packages.
 - `tsconfig.scripts.json` defines shared TypeScript settings for directories in `scripts/`.
-- `packages/**/tsconfig.json` (and `scripts/create-package/package-template/tsconfig.json`) defines TypeScript settings for each package that are meant to be used by code editors and lint tasks.
-- `packages/**/tsconfig.build.json` (and `scripts/create-package/package-template/tsconfig.build.json`) defines TypeScript settings for each package that are used to produce a build.
+- The root `lint:tsc` script checks repository scripts with `tsconfig.json`, then checks each
+  workspace package configuration directly. It does not build Snap bundles with `tsc`.
+- `packages/**/tsconfig.json` (and `scripts/create-package/package-template/tsconfig.json`) defines TypeScript settings for each package that are meant to be used by code editors and type checking.
+- Library packages and the package template also have `tsconfig.build.json` files for `ts-bridge` declaration builds. Snap packages do not have build configs because `mm-snap` builds their bundles.
 - `scripts/create-package/tsconfig.json` customizes TypeScript settings for the `create-package` tool.
 
 #### Jest

@@ -245,9 +245,6 @@
     }
   },
   "packages/solana-wallet-snap/src/core/handlers/onKeyringRequest/Keyring.ts": {
-    "@typescript-eslint/no-base-to-string": {
-      "count": 1
-    },
     "@typescript-eslint/no-explicit-any": {
       "count": 10
     },
@@ -258,7 +255,7 @@
       "count": 1
     },
     "@typescript-eslint/restrict-template-expressions": {
-      "count": 2
+      "count": 1
     },
     "no-restricted-syntax": {
       "count": 1

@@ -78,7 +78,7 @@ module.exports = {
 
   // A map from regular expressions to module names or to arrays of module names that allow to stub out resources with a single module
   // Here we ensure that Jest resolves `@metamask/*` imports to the uncompiled source code for packages that live in this repo.
-  // NOTE: This must be synchronized with the `paths` option in `tsconfig.base.json`.
+  // NOTE: This must be synchronized with the `paths` option in `tsconfig.packages.json`.
   moduleNameMapper: {
     '^@metamask/json-rpc-engine/v2$': [
       '<rootDir>/../json-rpc-engine/src/v2/index.ts',

@@ -19,13 +19,14 @@
     "changelog:validate": "yarn workspaces foreach --all --no-private --parallel --interlaced --verbose run changelog:validate",
     "create-release-branch": "create-release-branch --formatter oxfmt",
     "create-package": "tsx scripts/create-package",
-    "lint": "yarn lint:eslint && echo && yarn lint:misc --check && yarn constraints && yarn lint:dependencies && yarn readme-content:check",
+    "lint": "yarn lint:tsc && yarn lint:eslint && echo && yarn lint:misc --check && yarn constraints && yarn lint:dependencies && yarn readme-content:check",
     "lint:dependencies": "depcheck && yarn dedupe --check",
     "lint:dependencies:fix": "depcheck && yarn dedupe",
     "lint:eslint": "yarn eslint",
     "lint:fix": "yarn lint:eslint --fix --prune-suppressions && echo && yarn lint:misc --write && yarn constraints --fix && yarn lint:dependencies:fix && yarn readme-content:update",
     "lint:misc": "oxfmt --ignore-path .gitignore",
     "lint:misc:check": "yarn lint:misc --check",
+    "lint:tsc": "tsc --project tsconfig.json && yarn workspaces foreach --all exec tsc --project tsconfig.json --noEmit",
     "prepack": "./scripts/prepack.sh",
     "readme-content:check": "tsx scripts/update-readme-content.ts --check",
     "readme-content:update": "tsx scripts/update-readme-content.ts",

@@ -25,7 +25,7 @@ const config = {
   coverageThreshold: {
     global: {
       branches: 65.5,
-      functions: 62.64,
+      functions: 61.63,
       lines: 75.29,
       statements: 74.57,
     },

@@ -6,6 +6,9 @@ dotenv();
 
 const config: SnapConfig = {
   input: resolve(__dirname, 'src/index.ts'),
+  typescript: {
+    enabled: true,
+  },
   server: {
     port: 8080,
   },

@@ -7,7 +7,7 @@
     "url": "https://github.com/MetaMask/internal-snaps.git"
   },
   "source": {
-    "shasum": "ZEMZtj4BZq+pj3bzb81K1Vk5WQuqMA0NArfIhrIppds=",
+    "shasum": "N40X9yuzuO3nWtRwrVRhAMQC1+XOcB3Ay3sxYrg2YFA=",
     "location": {
       "npm": {
         "filePath": "dist/bundle.js",

@@ -1,5 +1,5 @@
 import { getSelectedAccounts } from '@metamask/keyring-snap-sdk';
-import { InFlightCoalescer } from '@metamask/snap-networks-utils/dedupe';
+import { InFlightCoalescer } from '@metamask/snap-networks-utils';
 import type { JsonRpcRequest, SnapsProvider } from '@metamask/snaps-sdk';
 import { array, assert, object, string } from 'superstruct';
 

@@ -8,6 +8,7 @@ import {
   xpriv_to_descriptor,
   xpub_to_descriptor,
 } from '@metamask/bitcoindevkit';
+import type { BIP32Node } from '@metamask/key-tree';
 import { SLIP10Node } from '@metamask/key-tree';
 import { v4 } from 'uuid';
 
@@ -271,7 +272,7 @@ export class BdkAccountRepository implements BitcoinAccountRepository {
       const parentNode = parentNodes.get(parentKey) as SLIP10Node;
       const childSegment = derivationPath[derivationPath.length - 1] as string;
       const childNode = (
-        await parentNode.derive([`bip32:${childSegment}`])
+        await parentNode.derive([`bip32:${childSegment}` as BIP32Node])
       ).neuter();
 
       accounts.push(

@@ -2,19 +2,25 @@
   "extends": "../../tsconfig.packages.json",
   "compilerOptions": {
     "baseUrl": "./",
-    "lib": ["ES2021", "DOM"],
-    "resolveJsonModule": true /*  lets us import JSON modules from within TypeScript modules. */,
     "jsx": "react-jsx",
     "jsxImportSource": "@metamask/snaps-sdk",
+    "resolveJsonModule": true,
     "exactOptionalPropertyTypes": false,
     "forceConsistentCasingInFileNames": true,
     "noErrorTruncation": true,
     "noUncheckedIndexedAccess": true,
     "skipLibCheck": true,
-    "module": "ESNext",
+    "lib": ["ES2023", "DOM"],
+    "target": "es2023",
+    "module": "preserve",
     "moduleResolution": "bundler",
     "types": ["jest"]
   },
-  "references": [{ "path": "../snap-networks-utils" }],
-  "include": ["**/*.ts", "**/*.tsx", "locales/*.json"]
+  "include": [
+    "**/*.ts",
+    "**/*.tsx",
+    "locales/*.json",
+    "snap.manifest.json",
+    "src/**/*.json"
+  ]
 }
@@ -5,6 +5,9 @@ import { resolve } from 'path';
 const config: SnapConfig = {
   // eslint-disable-next-line no-restricted-globals
   input: resolve(__dirname, 'src/index.tsx'),
+  typescript: {
+    enabled: true,
+  },
   server: {
     port: 8080,
   },

@@ -7,7 +7,7 @@
     "url": "https://github.com/MetaMask/internal-snaps.git"
   },
   "source": {
-    "shasum": "7jzuMWjDr1T5dgRV5M6B8ZtNPxPBNmGV2JGWgkvtTdA=",
+    "shasum": "Sno6Wef4OjbtlPw43N9uwVEHYoNlIjEiAgdEIjqVd4c=",
     "location": {
       "npm": {
         "filePath": "dist/bundle.js",

@@ -49,6 +49,7 @@ export {
   isSnapRpcError,
   normalizeError,
 } from './utils/errors';
+export { InFlightCoalescer } from './utils/dedupe/InFlightCoalescer';
 export type {
   CreateSnapErrorHandlingOptions,
   CreateTrackErrorOptions,

@@ -1,10 +1,18 @@
 {
-  "extends": "../../tsconfig.packages.build.json",
+  "extends": "./tsconfig.json",
   "compilerOptions": {
     "baseUrl": "./",
+    "composite": true,
+    "declaration": true,
+    "declarationMap": true,
+    "emitDeclarationOnly": true,
+    "inlineSources": true,
+    "noEmit": false,
+    "sourceMap": true,
     "outDir": "./dist",
     "rootDir": "./src"
   },
   "references": [],
-  "include": ["../../types", "./src"]
+  "include": ["../../types", "./src"],
+  "exclude": ["**/*.test.ts", "**/tests", "**/jest.config.ts"]
 }
@@ -5,6 +5,5 @@
     "skipLibCheck": true,
     "types": ["jest"]
   },
-  "references": [],
   "include": ["../../types", "./src"]
 }
@@ -27,6 +27,9 @@ const environment = {
 
 const config: SnapConfig = {
   input: resolve(__dirname, 'src/index.ts'),
+  typescript: {
+    enabled: true,
+  },
   server: {
     port: 8080,
   },

@@ -7,7 +7,7 @@
     "url": "https://github.com/MetaMask/internal-snaps.git"
   },
   "source": {
-    "shasum": "RP8K+BdAavCCQ3ZxXRx/CgH4ipA4Y2K/yCmqQTgHB8w=",
+    "shasum": "f67A1dy0bXl9jvoMuZ4heLBBs+m6bwaU20/WT30COeU=",
     "location": {
       "npm": {
         "filePath": "dist/bundle.js",

@@ -398,7 +398,9 @@ export const ValidationResponseStruct = object({
   valid: boolean(),
   errors: array(
     object({
-      code: enums(Object.values(SendErrorCodes)),
+      code: enums(
+        Object.values(SendErrorCodes) as [SendErrorCodes, ...SendErrorCodes[]],
+      ),
     }),
   ),
 });
@@ -423,7 +425,7 @@ export const ComputeFeeRequestStruct = object({
 
 export const ComputeFeeResponseStruct = array(
   object({
-    type: enums(Object.values(FeeType)),
+    type: enums(Object.values(FeeType) as [FeeType, ...FeeType[]]),
     asset: AssetStruct,
   }),
 );

@@ -10,6 +10,7 @@ import bs58 from 'bs58';
 
 import type { AssetEntity } from '../../../entities';
 import { asStrictKeyringAccount } from '../../../entities';
+import type { Caip10Address } from '../../constants/solana';
 import { KnownCaip19Id, Network } from '../../constants/solana';
 import type {
   AssetsService,
@@ -414,7 +415,7 @@ describe('SolanaKeyring', () => {
         jsonrpc: '2.0',
         ...MOCK_SIGN_AND_SEND_TRANSACTION_REQUEST,
       } as unknown as JsonRpcRequest;
-      const mockResolvedAddress = `${mockScope}:resolved-address`;
+      const mockResolvedAddress: Caip10Address = `${mockScope}:resolved-address`;
 
       jest
         .spyOn(mockWalletService, 'resolveAccountAddress')

@@ -24,8 +24,8 @@ import type {
   ExportedAccount,
   KeyringSnapRpc,
 } from '@metamask/keyring-api/v2';
-import { UuidStruct } from '@metamask/snap-networks-utils';
 import type { Logger } from '@metamask/snap-networks-utils';
+import { UuidStruct } from '@metamask/snap-networks-utils';
 import type { CaipAssetType, JsonRpcRequest } from '@metamask/snaps-sdk';
 import {
   InvalidParamsError,

@@ -37,7 +37,7 @@ const CommaSeparatedListOfStringsStruct = coerce(
 
 const EnvStruct = object({
   ENVIRONMENT: enums(['local', 'test', 'production']),
-  LOG_LEVEL: enums(Object.values(LogLevel)),
+  LOG_LEVEL: enums(Object.values(LogLevel) as [LogLevel, ...LogLevel[]]),
   RPC_URL_MAINNET_LIST: CommaSeparatedListOfUrlsStruct,
   RPC_URL_DEVNET_LIST: CommaSeparatedListOfUrlsStruct,
   RPC_URL_TESTNET_LIST: CommaSeparatedListOfUrlsStruct,

@@ -215,7 +215,7 @@ export class TransactionScanService {
               symbol:
                 'symbol' in asset.asset ? asset.asset.symbol : asset.asset_type,
               name: 'name' in asset.asset ? asset.asset.name : asset.asset_type,
-              logo: 'logo' in asset.asset ? asset.asset.logo : null,
+              logo: ('logo' in asset.asset ? asset.asset.logo : null) ?? null,
               value: asset.in?.value ?? asset.out?.value ?? null,
               price: asset.in?.usd_price ?? asset.out?.usd_price ?? null,
             }),
@@ -230,7 +230,9 @@ export class TransactionScanService {
             type:
               'type' in result.error_details ? result.error_details.type : null,
             code:
-              'code' in result.error_details ? result.error_details.code : null,
+              ('code' in result.error_details
+                ? result.error_details.code
+                : null) ?? null,
           }
         : null,
     };

@@ -34,7 +34,9 @@ import { Base58Struct, Base64Struct } from '../../validation/structs';
  * @see https://github.com/anza-xyz/wallet-standard/tree/master/packages/core/features/src
  */
 
-export const ScopeStringStruct = enums(Object.values(Network));
+export const ScopeStringStruct = enums(
+  Object.values(Network) as [Network, ...Network[]],
+);
 
 // Sanitizing structs that transform values during validation
 const SanitizedSolanaAddressStruct = coerce(

@@ -60,9 +60,13 @@ export const GetAccounBalancesResponseStruct = record(
 
 export const ListAccountAssetsResponseStruct = array(CaipAssetTypeStruct);
 
-export const SubmitRequestMethodStruct = enums(Object.values(SolMethod));
+export const SubmitRequestMethodStruct = enums(
+  Object.values(SolMethod) as [SolMethod, ...SolMethod[]],
+);
 
-export const NetworkStruct = enums(Object.values(Network));
+export const NetworkStruct = enums(
+  Object.values(Network) as [Network, ...Network[]],
+);
 
 export const Curenc = enums([
   'btc',

@@ -59,12 +59,14 @@ BigNumber.config({ EXPONENTIAL_AT: 16 });
  * @param args - The request handler args as object.
  * @param args.origin - The origin of the request, e.g., the website that
  * invoked the snap.
+ * @param args.originMetadata - Metadata reported by the requesting origin.
  * @param args.request - A validated JSON-RPC request object.
  * @returns A promise that resolves to the result of the RPC request.
  * @throws If the request method is not valid for this snap.
  */
 export const onRpcRequest: OnRpcRequestHandler = async ({
   origin,
+  originMetadata,
   request,
 }) => {
   logger.log('[🔄 onRpcRequest]', request.method, request);
@@ -84,7 +86,7 @@ export const onRpcRequest: OnRpcRequestHandler = async ({
   }
 
   const result = await withCatchAndThrowSnapError(async () =>
-    handler({ origin, request }),
+    handler({ origin, originMetadata, request }),
   );
 
   return result ?? null;
@@ -179,13 +181,12 @@ export const onCronjob: OnCronjobHandler = async ({ request }) => {
   _logger.log(request.method, request);
 
   const { method } = request;
-  assert(
-    method,
-    enums([
-      ...Object.values(CronjobMethod),
-      ...Object.values(ScheduleBackgroundEventMethod),
-    ]),
-  );
+  const validMethods = [
+    ...Object.values(CronjobMethod),
+    ...Object.values(ScheduleBackgroundEventMethod),
+  ];
+
+  assert(method, enums(validMethods as [string, ...string[]]));
 
   const result = await withCatchAndThrowSnapError(async () => {
     _logger.log('Running cronjob', { method });
@@ -197,10 +198,7 @@ export const onCronjob: OnCronjobHandler = async ({ request }) => {
 
     if (!handler) {
       throw new MethodNotFoundError(
-        `Cronjob / ScheduleBackgroundEvent method ${String(method)} not found. Available methods: ${[
-          ...Object.values(CronjobMethod),
-          ...Object.values(ScheduleBackgroundEventMethod),
-        ].join(',')}`,
+        `Cronjob / ScheduleBackgroundEvent method ${method} not found. Available methods: ${validMethods.toString()}`,
       ) as unknown as Error;
     }
     return handler({ request });