diff --git a/packages/api/src/__tests__/bounty_detail.test.ts b/packages/api/src/__tests__/bounty_detail.test.ts
new file mode 100644
index 0000000..e762d4f
--- /dev/null
+++ b/packages/api/src/__tests__/bounty_detail.test.ts
@@ -0,0 +1,97 @@
+import { describe, it, expect, beforeAll, vi } from 'vitest';
+import { createApp } from '../app';
+import { verify } from 'hono/jwt';
+import { db } from '../db';
+
+vi.mock('hono/jwt', () => ({
+    verify: vi.fn(),
+}));
+
+vi.mock('../db', () => ({
+    db: {
+        query: {
+            bounties: {
+                findFirst: vi.fn(),
+            },
+            applications: {
+                findMany: vi.fn(),
+            },
+        },
+    },
+}));
+
+describe('GET /api/bounties/:id', () => {
+    let app: ReturnType<typeof createApp>;
+
+    beforeAll(() => {
+        app = createApp();
+
+        vi.mocked(verify).mockResolvedValue({
+            sub: 'test-user-id',
+            username: 'testuser',
+            exp: Math.floor(Date.now() / 1000) + 3600,
+        });
+
+        process.env.JWT_PUBLIC_KEY = '-----BEGIN PUBLIC KEY-----\nfake\n-----END PUBLIC KEY-----';
+    });
+
+    it('returns bounty detail with creator, application count, assignee, and status', async () => {
+        vi.mocked(db.query.bounties.findFirst).mockResolvedValue({
+            id: 'b1',
+            title: 'Fix API bug',
+            status: 'assigned',
+            creator: {
+                id: 'u1',
+                username: 'creator-user',
+                avatarUrl: 'https://example.com/avatar.png',
+            },
+            assignee: {
+                id: 'u2',
+                username: 'assigned-user',
+                avatarUrl: 'https://example.com/assigned.png',
+            },
+        } as any);
+
+        vi.mocked(db.query.applications.findMany).mockResolvedValue([
+            { id: 'a1' },
+            { id: 'a2' },
+        ] as any);
+
+        const res = await app.request('/api/bounties/b1', {
+            headers: {
+                Authorization: 'Bearer valid.token',
+            },
+        });
+
+        expect(res.status).toBe(200);
+        const body = await res.json();
+
+        expect(body.id).toBe('b1');
+        expect(body.status).toBe('assigned');
+        expect(body.creator).toEqual({
+            id: 'u1',
+            username: 'creator-user',
+            avatarUrl: 'https://example.com/avatar.png',
+        });
+        expect(body.assignee).toEqual({
+            id: 'u2',
+            username: 'assigned-user',
+            avatarUrl: 'https://example.com/assigned.png',
+        });
+        expect(body.applicationCount).toBe(2);
+    });
+
+    it('returns 404 when bounty is not found', async () => {
+        vi.mocked(db.query.bounties.findFirst).mockResolvedValue(null as any);
+
+        const res = await app.request('/api/bounties/missing', {
+            headers: {
+                Authorization: 'Bearer valid.token',
+            },
+        });
+
+        expect(res.status).toBe(404);
+        const body = await res.json();
+        expect(body.error).toBe('Bounty not found');
+    });
+});
diff --git a/packages/api/src/routes/bounties.ts b/packages/api/src/routes/bounties.ts
index 2f4f6e6..80ec60f 100644
--- a/packages/api/src/routes/bounties.ts
+++ b/packages/api/src/routes/bounties.ts
@@ -2,7 +2,7 @@ import { Hono } from 'hono';
 import { Variables } from '../middleware/auth';
 import { ensureBountyCreator, ensureBountyAssignee } from '../middleware/resource-auth';
 import { db } from '../db';
-import { bounties } from '../db/schema';
+import { applications, bounties } from '../db/schema';
 import { eq, and, gte, lte, sql, desc, or, lt } from 'drizzle-orm';
 
 const bountiesRouter = new Hono<{ Variables: Variables }>();
@@ -130,13 +130,37 @@ bountiesRouter.get('/:id', async (c) => {
     const id = c.req.param('id');
     const bounty = await db.query.bounties.findFirst({
         where: eq(bounties.id, id),
+        with: {
+            creator: {
+                columns: {
+                    id: true,
+                    username: true,
+                    avatarUrl: true,
+                },
+            },
+            assignee: {
+                columns: {
+                    id: true,
+                    username: true,
+                    avatarUrl: true,
+                },
+            },
+        },
     });
 
     if (!bounty) {
         return c.json({ error: 'Bounty not found' }, 404);
     }
 
-    return c.json(bounty);
+    const bountyApplications = await db.query.applications.findMany({
+        columns: { id: true },
+        where: eq(applications.bountyId, id),
+    });
+
+    return c.json({
+        ...bounty,
+        applicationCount: bountyApplications.length,
+    });
 });
 
 /**