feat: add SnapKeyring.setSelectedAccounts and getSelectedAccounts support (#387)

This PR adds methods for setting selected accounts and getting selected
accounts for a snap.


## Examples

N/A

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> Introduces a new `keyring_setSelectedAccounts` RPC with client/server
handling, adds Snap-side `getSelectedAccounts`, and updates the Snap
keyring to track and propagate per-snap selected accounts.
> 
> - **API (`@metamask/keyring-api`)**:
> - Add `KeyringRpcMethod.SetSelectedAccounts` and structs
`SetSelectedAccountsRequest/Response`.
> - Extend `Keyring` interface with `setSelectedAccounts(accounts:
AccountId[])`.
> - **Client (`@metamask/keyring-snap-client`)**:
> - Implement `setSelectedAccounts(accounts)` sending
`keyring_setSelectedAccounts`.
> - **Snap SDK (`@metamask/keyring-snap-sdk`)**:
> - New `methods` module with
`SnapManageAccountsMethod.GetSelectedAccounts` and request/response
structs.
>   - Add `getSelectedAccounts(snap)` helper; export from SDK index.
> - Update keyring RPC handler to support `keyring_setSelectedAccounts`.
> - **Snap Bridge (`@metamask/eth-snap-keyring`)**:
> - Track selected accounts per Snap; implement `setSelectedAccounts` to
update in-memory map and call each Snap via internal client.
> - Handle `snap_manageAccounts` method `getSelectedAccounts` to return
selection for the requesting Snap.
>   - Enhance `SnapIdMap` with `getSnapId(key)`.
> - Add dependency on `@metamask/keyring-snap-sdk`; update tsconfig
references and README dependency graph.
> - **Tests**:
> - Add/extend tests for new RPC, client method, Snap keyring selection
behavior, `getSelectedAccounts`, and `SnapIdMap.getSnapId()`.
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
582d075. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

Author: hmalik88

README.md

@@ -66,6 +66,7 @@ linkStyle default opacity:0.5
   eth_snap_keyring --> keyring_api;
   eth_snap_keyring --> keyring_internal_api;
   eth_snap_keyring --> keyring_internal_snap_client;
+  eth_snap_keyring --> keyring_snap_sdk;
   eth_snap_keyring --> keyring_utils;
   keyring_snap_client --> keyring_api;
   keyring_snap_client --> keyring_utils;

packages/keyring-api/src/api/keyring.ts

@@ -1,7 +1,7 @@
 /* eslint-disable @typescript-eslint/no-redundant-type-constituents */
 // This rule seems to be triggering a false positive on the `KeyringAccount`.
 
-import type { JsonRpcRequest } from '@metamask/keyring-utils';
+import type { AccountId, JsonRpcRequest } from '@metamask/keyring-utils';
 import type { Json } from '@metamask/utils';
 
 import type { KeyringAccount } from './account';
@@ -159,6 +159,13 @@ export type Keyring = {
     request: JsonRpcRequest,
   ): Promise<ResolvedAccountAddress | null>;
 
+  /**
+   * Set the selected accounts.
+   *
+   * @param accounts - The accounts to set as selected.
+   */
+  setSelectedAccounts?(accounts: AccountId[]): Promise<void>;
+
   /**
    * Filter supported chains for a given account.
    *

packages/keyring-api/src/rpc.ts

@@ -51,6 +51,7 @@ export enum KeyringRpcMethod {
   SubmitRequest = 'keyring_submitRequest',
   ApproveRequest = 'keyring_approveRequest',
   RejectRequest = 'keyring_rejectRequest',
+  SetSelectedAccounts = 'keyring_setSelectedAccounts',
 }
 
 /**
@@ -118,6 +119,27 @@ export const CreateAccountResponseStruct = KeyringAccountStruct;
 
 export type CreateAccountResponse = Infer<typeof CreateAccountResponseStruct>;
 
+// ----------------------------------------------------------------------------
+// Set selected accounts
+
+export const SetSelectedAccountsRequestStruct = object({
+  ...CommonHeader,
+  method: literal('keyring_setSelectedAccounts'),
+  params: object({
+    accounts: array(string()),
+  }),
+});
+
+export type SetSelectedAccountsRequest = Infer<
+  typeof SetSelectedAccountsRequestStruct
+>;
+
+export const SetSelectedAccountsResponseStruct = literal(null);
+
+export type SetSelectedAccountsResponse = Infer<
+  typeof SetSelectedAccountsResponseStruct
+>;
+
 // ----------------------------------------------------------------------------
 // Discover accounts
 

packages/keyring-snap-bridge/package.json

@@ -43,6 +43,7 @@
     "@metamask/keyring-api": "workspace:^",
     "@metamask/keyring-internal-api": "workspace:^",
     "@metamask/keyring-internal-snap-client": "workspace:^",
+    "@metamask/keyring-snap-sdk": "workspace:^",
     "@metamask/keyring-utils": "workspace:^",
     "@metamask/superstruct": "^3.1.0",
     "@metamask/utils": "^11.1.0",

packages/keyring-snap-bridge/src/SnapIdMap.test.ts

@@ -97,6 +97,21 @@ describe('SnapIdMap', () => {
     });
   });
 
+  describe('getSnapId', () => {
+    it('returns undefined when the key is not in the map', () => {
+      const map = new SnapIdMap<{ snapId: SnapId; value: number }>();
+      const snapId = map.getSnapId('foo');
+      expect(snapId).toBeUndefined();
+    });
+
+    it('returns the snapId when the key is in the map', () => {
+      const map = new SnapIdMap<{ snapId: SnapId; value: number }>();
+      map.set('foo', { snapId: SNAP_1_ID, value: 1 });
+      const snapId = map.getSnapId('foo');
+      expect(snapId).toBe(SNAP_1_ID);
+    });
+  });
+
   describe('pop', () => {
     it('returns undefined when the key is not in the map', () => {
       const map = new SnapIdMap<{ snapId: SnapId; value: number }>();

packages/keyring-snap-bridge/src/SnapIdMap.ts

@@ -132,6 +132,16 @@ export class SnapIdMap<Value extends { snapId: SnapId }> {
     return value?.snapId === snapId ? value : undefined;
   }
 
+  /**
+   * Gets a Snap ID that's associated with the given key from the map.
+   *
+   * @param key - Key of the element to get.
+   * @returns The Snap ID associated with the given key.
+   */
+  getSnapId(key: string): SnapId | undefined {
+    return this.#map.get(key)?.snapId;
+  }
+
   /**
    * Gets and delete a value from the map.
    *

packages/keyring-snap-bridge/src/SnapKeyring.test.ts

@@ -30,6 +30,7 @@ import {
   TrxMethod,
   TrxAccountType,
 } from '@metamask/keyring-api';
+import { SnapManageAccountsMethod } from '@metamask/keyring-snap-sdk';
 import type { JsonRpcRequest } from '@metamask/keyring-utils';
 import type { HandleSnapRequest } from '@metamask/snaps-controllers';
 import { type SnapId } from '@metamask/snaps-sdk';
@@ -1359,6 +1360,37 @@ describe('SnapKeyring', () => {
       });
     });
 
+    describe('#handleGetSelectedAccounts', () => {
+      it('gets the selected accounts', async () => {
+        mockMessenger.handleRequest.mockResolvedValue(null);
+        await keyring.setSelectedAccounts([solDataAccount.id]);
+        const result = await keyring.handleKeyringSnapMessage(snapId, {
+          method: SnapManageAccountsMethod.GetSelectedAccounts,
+        });
+        expect(result).toStrictEqual([solDataAccount.id]);
+      });
+
+      it('returns an empty array if no accounts are selected', async () => {
+        mockMessenger.handleRequest.mockResolvedValue(null);
+        const result = await keyring.handleKeyringSnapMessage(snapId, {
+          method: SnapManageAccountsMethod.GetSelectedAccounts,
+        });
+        expect(result).toStrictEqual([]);
+      });
+
+      it('ignores an account that does not belong to a snap', async () => {
+        mockMessenger.handleRequest.mockResolvedValue(null);
+        await keyring.setSelectedAccounts([
+          unknownAccount.id,
+          ethEoaAccount1.id,
+        ]);
+        const result = await keyring.handleKeyringSnapMessage(snapId, {
+          method: SnapManageAccountsMethod.GetSelectedAccounts,
+        });
+        expect(result).toStrictEqual([ethEoaAccount1.id]);
+      });
+    });
+
     it('fails when the method is invalid', async () => {
       await expect(
         keyring.handleKeyringSnapMessage(snapId, {
@@ -1387,6 +1419,33 @@ describe('SnapKeyring', () => {
     });
   });
 
+  describe('setSelectedAccounts', () => {
+    beforeEach(() => {
+      mockMessengerHandleRequest({
+        [KeyringRpcMethod.SetSelectedAccounts]: () => null,
+      });
+    });
+
+    it('sets the selected accounts', async () => {
+      await keyring.setSelectedAccounts([ethEoaAccount1.id]);
+      const result = await keyring.handleKeyringSnapMessage(snapId, {
+        method: SnapManageAccountsMethod.GetSelectedAccounts,
+      });
+      expect(result).toStrictEqual([ethEoaAccount1.id]);
+    });
+
+    it('logs an error if the setSelectedAccounts call for a snap fails', async () => {
+      const spy = jest.spyOn(console, 'error').mockImplementation();
+      mockMessenger.handleRequest.mockImplementation(() => {
+        throw new Error('Failed to set selected accounts');
+      });
+      await keyring.setSelectedAccounts([ethEoaAccount1.id]);
+      expect(spy).toHaveBeenCalledWith(
+        `Failed to set selected accounts for ${snapId} snap: 'Failed to set selected accounts'`,
+      );
+    });
+  });
+
   describe('serialize', () => {
     it('returns the keyring state', async () => {
       const expectedState = {

packages/keyring-snap-bridge/src/SnapKeyring.ts

@@ -39,6 +39,11 @@ import {
   type InternalAccount,
 } from '@metamask/keyring-internal-api';
 import { KeyringInternalSnapClient } from '@metamask/keyring-internal-snap-client';
+import {
+  type GetSelectedAccountsResponse,
+  GetSelectedAccountsRequestStruct,
+  SnapManageAccountsMethod,
+} from '@metamask/keyring-snap-sdk';
 import type { AccountId, JsonRpcRequest } from '@metamask/keyring-utils';
 import { strictMask } from '@metamask/keyring-utils';
 import type { SnapId } from '@metamask/snaps-sdk';
@@ -183,6 +188,11 @@ export class SnapKeyring {
     snapId: SnapId;
   }>;
 
+  /**
+   * Mapping between Snap IDs and the selected accounts.
+   */
+  readonly #selectedAccounts: Map<SnapId, AccountId[]>;
+
   /**
    * Mapping between request IDs and their deferred promises.
    */
@@ -238,6 +248,7 @@ export class SnapKeyring {
     this.#options = new SnapIdMap();
     this.#callbacks = callbacks;
     this.#isAnyAccountTypeAllowed = isAnyAccountTypeAllowed;
+    this.#selectedAccounts = new Map();
   }
 
   /**
@@ -497,6 +508,21 @@ export class SnapKeyring {
     return null;
   }
 
+  /**
+   * Handle a Get Selected Accounts method call from a Snap.
+   *
+   * @param snapId - Snap ID.
+   * @param message - Method call message.
+   * @returns The selected accounts.
+   */
+  async #handleGetSelectedAccounts(
+    snapId: SnapId,
+    message: SnapMessage,
+  ): Promise<GetSelectedAccountsResponse> {
+    assert(message, GetSelectedAccountsRequestStruct);
+    return this.#selectedAccounts.get(snapId) ?? [];
+  }
+
   /**
    * Handle an Request Approved event from a Snap.
    *
@@ -701,6 +727,10 @@ export class SnapKeyring {
         return this.#handleAccountTransactionsUpdated(snapId, message);
       }
 
+      case `${SnapManageAccountsMethod.GetSelectedAccounts}`: {
+        return this.#handleGetSelectedAccounts(snapId, message);
+      }
+
       default:
         throw new Error(`Method not supported: ${message.method}`);
     }
@@ -1497,6 +1527,48 @@ export class SnapKeyring {
     );
   }
 
+  /**
+   * Update the in-memory selected accounts map.
+   *
+   * @param accounts - The accounts to update the map with.
+   */
+  #updateSelectedAccountsMap(accounts: AccountId[]): void {
+    const selectedAccounts = this.#selectedAccounts;
+    selectedAccounts.clear();
+    for (const account of accounts) {
+      const snapId = this.#accounts.getSnapId(account);
+      if (!snapId) {
+        continue;
+      }
+      const snapAccounts = selectedAccounts.get(snapId) ?? [];
+      snapAccounts.push(account);
+      selectedAccounts.set(snapId, snapAccounts);
+    }
+  }
+
+  /**
+   * Set the selected accounts.
+   *
+   * @param accounts - The accounts to set as selected.
+   */
+  async setSelectedAccounts(accounts: AccountId[]): Promise<void> {
+    this.#updateSelectedAccountsMap(accounts);
+    const entries = [...this.#selectedAccounts.entries()];
+    await Promise.all(
+      entries.map(async ([snapId, accountIds]) => {
+        try {
+          await this.#snapClient
+            .withSnapId(snapId)
+            .setSelectedAccounts(accountIds);
+        } catch (error: any) {
+          console.error(
+            `Failed to set selected accounts for ${snapId} snap: '${error.message}'`,
+          );
+        }
+      }),
+    );
+  }
+
   /**
    * Get the Snap associated with the given Snap ID.
    *

packages/keyring-snap-bridge/tsconfig.build.json

@@ -14,7 +14,8 @@
     { "path": "../keyring-api/tsconfig.build.json" },
     { "path": "../keyring-internal-api/tsconfig.build.json" },
     { "path": "../keyring-internal-snap-client/tsconfig.build.json" },
-    { "path": "../keyring-utils/tsconfig.build.json" }
+    { "path": "../keyring-utils/tsconfig.build.json" },
+    { "path": "../keyring-snap-sdk/tsconfig.build.json" }
   ],
   "include": ["./src/**/*.ts"],
   "exclude": ["./src/**/*.test.ts"]

packages/keyring-snap-bridge/tsconfig.json

@@ -10,7 +10,8 @@
     { "path": "../keyring-api/tsconfig.build.json" },
     { "path": "../keyring-internal-api/tsconfig.build.json" },
     { "path": "../keyring-internal-snap-client/tsconfig.build.json" },
-    { "path": "../keyring-utils/tsconfig.build.json" }
+    { "path": "../keyring-utils/tsconfig.build.json" },
+    { "path": "../keyring-snap-sdk/tsconfig.build.json" }
   ],
   "include": ["./src"],
   "exclude": ["./dist/**/*"]