diff --git a/apps/server/trpc/router.test.ts b/apps/server/trpc/router.test.ts
index c585ce5..eb64e50 100644
--- a/apps/server/trpc/router.test.ts
+++ b/apps/server/trpc/router.test.ts
@@ -14,6 +14,7 @@ import {
 } from './index.js';
 import type { TRPCContext } from './context.js';
 import type { EventBus } from '../events/types.js';
+import type { AccountRepository } from '../db/repositories/account-repository.js';
 
 // Create caller factory for the app router
 const createCaller = createCallerFactory(appRouter);
@@ -161,6 +162,74 @@ describe('tRPC Router', () => {
     });
   });
 
+  describe('addAccountByToken procedure', () => {
+    let mockRepo: AccountRepository;
+    let caller: ReturnType<typeof createCaller>;
+
+    beforeEach(() => {
+      vi.resetAllMocks();
+      mockRepo = {
+        findByEmail: vi.fn(),
+        updateAccountAuth: vi.fn(),
+        create: vi.fn(),
+      } as unknown as AccountRepository;
+      const ctx = createTestContext({ accountRepository: mockRepo });
+      caller = createCaller(ctx);
+    });
+
+    it('creates a new account and returns { upserted: false, account }', async () => {
+      const stubAccount = { id: 'acc-1', email: 'new@example.com', provider: 'claude' };
+      vi.mocked(mockRepo.findByEmail).mockResolvedValue(null);
+      vi.mocked(mockRepo.create).mockResolvedValue(stubAccount as any);
+
+      const result = await caller.addAccountByToken({ email: 'new@example.com', token: 'tok-abc' });
+
+      expect(result).toEqual({ upserted: false, account: stubAccount });
+      expect(mockRepo.create).toHaveBeenCalledWith({
+        email: 'new@example.com',
+        provider: 'claude',
+        configJson: '{"hasCompletedOnboarding":true}',
+        credentials: '{"claudeAiOauth":{"accessToken":"tok-abc"}}',
+      });
+      expect(mockRepo.updateAccountAuth).not.toHaveBeenCalled();
+    });
+
+    it('updates an existing account and returns { upserted: true, account }', async () => {
+      const existingAccount = { id: 'acc-existing', email: 'existing@example.com', provider: 'claude' };
+      const updatedAccount = { ...existingAccount, configJson: '{"hasCompletedOnboarding":true}' };
+      vi.mocked(mockRepo.findByEmail).mockResolvedValue(existingAccount as any);
+      vi.mocked(mockRepo.updateAccountAuth).mockResolvedValue(updatedAccount as any);
+
+      const result = await caller.addAccountByToken({ email: 'existing@example.com', token: 'tok-xyz' });
+
+      expect(result).toEqual({ upserted: true, account: updatedAccount });
+      expect(mockRepo.updateAccountAuth).toHaveBeenCalledWith(
+        'acc-existing',
+        '{"hasCompletedOnboarding":true}',
+        '{"claudeAiOauth":{"accessToken":"tok-xyz"}}',
+      );
+      expect(mockRepo.create).not.toHaveBeenCalled();
+    });
+
+    it('throws BAD_REQUEST when email is empty', async () => {
+      await expect(
+        caller.addAccountByToken({ email: '', provider: 'claude', token: 'tok' }),
+      ).rejects.toMatchObject({ code: 'BAD_REQUEST' });
+      expect(mockRepo.findByEmail).not.toHaveBeenCalled();
+      expect(mockRepo.create).not.toHaveBeenCalled();
+      expect(mockRepo.updateAccountAuth).not.toHaveBeenCalled();
+    });
+
+    it('throws BAD_REQUEST when token is empty', async () => {
+      await expect(
+        caller.addAccountByToken({ email: 'user@example.com', provider: 'claude', token: '' }),
+      ).rejects.toMatchObject({ code: 'BAD_REQUEST' });
+      expect(mockRepo.findByEmail).not.toHaveBeenCalled();
+      expect(mockRepo.create).not.toHaveBeenCalled();
+      expect(mockRepo.updateAccountAuth).not.toHaveBeenCalled();
+    });
+  });
+
   describe('Zod schema validation', () => {
     it('healthResponseSchema should reject invalid status', () => {
       const invalid = {
diff --git a/apps/server/trpc/routers/account.ts b/apps/server/trpc/routers/account.ts
index 99c638d..b40a4db 100644
--- a/apps/server/trpc/routers/account.ts
+++ b/apps/server/trpc/routers/account.ts
@@ -72,5 +72,29 @@ export function accountProcedures(publicProcedure: ProcedureBuilder) {
       .query(() => {
         return listProviderNames();
       }),
+
+    addAccountByToken: publicProcedure
+      .input(z.object({
+        email: z.string().min(1),
+        provider: z.string().default('claude'),
+        token: z.string().min(1),
+      }))
+      .mutation(async ({ ctx, input }) => {
+        const repo = requireAccountRepository(ctx);
+        const credentials = JSON.stringify({ claudeAiOauth: { accessToken: input.token } });
+        const configJson = JSON.stringify({ hasCompletedOnboarding: true });
+        const existing = await repo.findByEmail(input.email);
+        if (existing) {
+          const account = await repo.updateAccountAuth(existing.id, configJson, credentials);
+          return { upserted: true, account };
+        }
+        const account = await repo.create({
+          email: input.email,
+          provider: input.provider,
+          configJson,
+          credentials,
+        });
+        return { upserted: false, account };
+      }),
   };
 }
diff --git a/docs/server-api.md b/docs/server-api.md
index 2b69321..0f7341d 100644
--- a/docs/server-api.md
+++ b/docs/server-api.md
@@ -190,6 +190,7 @@ Each procedure uses `require*Repository(ctx)` helpers that throw `TRPCError(INTE
 | updateAccountAuth | mutation | Update credentials |
 | markAccountExhausted | mutation | Set exhaustion timer |
 | listProviderNames | query | Available provider names |
+| addAccountByToken | mutation | Upsert account from OAuth token; returns `{ upserted, account }` |
 
 ### Proposals
 | Procedure | Type | Description |