diff --git a/backend/prisma/seed.ts b/backend/prisma/seed.ts
index ccf856aa..a1d7f0fd 100644
--- a/backend/prisma/seed.ts
+++ b/backend/prisma/seed.ts
@@ -54,13 +54,22 @@ async function main() {
 
     console.log({ stream1 });
 
-    // Create an example event
-    const event1 = await prisma.streamEvent.create({
-        data: {
+    // Upsert an example event – keyed on the @@unique([transactionHash, eventType])
+    // constraint so re-running the seed never creates duplicate rows.
+    const DEMO_TX_HASH = '6f7e8a9b0c1d2e3f4a5b6c7d8e9f0a1b2c3d4e5f6g7h8i9j0k1l2m3n4o5p6q7r';
+    const event1 = await prisma.streamEvent.upsert({
+        where: {
+            transactionHash_eventType: {
+                transactionHash: DEMO_TX_HASH,
+                eventType: 'CREATED',
+            },
+        },
+        update: {},
+        create: {
             streamId: stream1.streamId,
             eventType: 'CREATED',
             amount: '1000000000000',
-            transactionHash: '6f7e8a9b0c1d2e3f4a5b6c7d8e9f0a1b2c3d4e5f6g7h8i9j0k1l2m3n4o5p6q7r',
+            transactionHash: DEMO_TX_HASH,
             ledgerSequence: 123456,
             timestamp: Math.floor(Date.now() / 1000),
             metadata: JSON.stringify({ memo: 'Seed data' }),
diff --git a/backend/src/controllers/stream.controller.ts b/backend/src/controllers/stream.controller.ts
index c453e67d..394c11ad 100644
--- a/backend/src/controllers/stream.controller.ts
+++ b/backend/src/controllers/stream.controller.ts
@@ -212,7 +212,7 @@ export const createStream = async (req: Request, res: Response) => {
       },
     });
 
-    return res.status(201).json(stream);
+    return res.status(201).json(JSON.parse(JSON.stringify(stream, (_key, value) => typeof value === "bigint" ? value.toString() : value)));
   } catch (error) {
     if (
       error instanceof RangeError ||
diff --git a/backend/src/workers/soroban-event-worker.ts b/backend/src/workers/soroban-event-worker.ts
index 45e74cd4..730c0a5f 100644
--- a/backend/src/workers/soroban-event-worker.ts
+++ b/backend/src/workers/soroban-event-worker.ts
@@ -1107,7 +1107,7 @@ export class SorobanEventWorker {
     }
 
     const sender = decodeAddress(body["sender"]);
-    const newEndTime = Number(decodeU64(body["new_end_time"]));
+    const newEndTime = decodeU64(body["new_end_time"]);
     const timestamp = Math.floor(Date.now() / 1000);
 
     await prisma.$transaction(async (tx: Prisma.TransactionClient) => {
@@ -1164,7 +1164,7 @@ export class SorobanEventWorker {
             timestamp,
             metadata: JSON.stringify({
               sender,
-              newEndTime,
+              newEndTime: newEndTime.toString(),
               pausedDuration: additionalPausedDuration,
               totalPausedDuration: newTotalPausedDuration,
             }),
@@ -1180,7 +1180,7 @@ export class SorobanEventWorker {
     sseService.broadcastToStream(String(streamId), "stream.resumed", {
       streamId,
       sender,
-      newEndTime,
+      newEndTime: newEndTime.toString(),
       transactionHash: event.txHash,
       ledger: event.ledger,
       timestamp,
diff --git a/backend/tests/stream.test.ts b/backend/tests/stream.test.ts
index a9c5822e..13410543 100644
--- a/backend/tests/stream.test.ts
+++ b/backend/tests/stream.test.ts
@@ -65,8 +65,8 @@ describe('POST /v1/streams', () => {
       ratePerSecond: '100',
       depositedAmount: '86400',
       withdrawnAmount: '0',
-      startTime: 1700000000,
-      lastUpdateTime: 1700000000,
+      startTime: 1700000000n,
+      lastUpdateTime: 1700000000n,
       isPaused: false,
       pausedAt: null,
       totalPausedDuration: 0,