Reject top-ups for paused or inactive streams

backend/src/controllers/stream.controller.ts

@@ -552,6 +552,20 @@ export const topUpStreamHandler = async (req: Request, res: Response) => {
       return res.status(403).json({ error: 'Only the stream sender may top up this stream' });
     }
 
+    if (stream.isPaused) {
+      return res.status(409).json({
+        error: 'Conflict',
+        message: 'Cannot top up a paused stream',
+      });
+    }
+
+    if (!stream.isActive) {
+      return res.status(409).json({
+        error: 'Conflict',
+        message: 'Cannot top up an inactive stream',
+      });
+    }
+
     const txHash = await topUpStream(streamId, amount, callerAddress);
 
     const newDeposited = (BigInt(stream.depositedAmount) + amount).toString();

backend/tests/integration/top-up.test.ts

@@ -148,6 +148,22 @@ describe('POST /v1/streams/:streamId/top-up', () => {
     expect(res.status).toBe(403);
   });
 
+  it('returns 409 when stream is inactive', async () => {
+    vi.mocked(mockPrisma.stream.findUnique).mockResolvedValue({
+      ...mockStream,
+      isActive: false,
+      isPaused: false,
+    } as any);
+
+    const res = await request(app)
+      .post('/v1/streams/42/top-up')
+      .set('Authorization', 'Bearer dummy')
+      .send({ amount: '1000' });
+
+    expect(res.status).toBe(409);
+    expect(topUpStream).not.toHaveBeenCalled();
+  });
+
   it('updates depositedAmount in DB on success', async () => {
     await request(app)
       .post('/v1/streams/42/top-up')