diff --git a/src/app/(dashboard)/jobs/[jobId]/page.tsx b/src/app/(dashboard)/jobs/[jobId]/page.tsx
index 75a0004..5eab726 100644
--- a/src/app/(dashboard)/jobs/[jobId]/page.tsx
+++ b/src/app/(dashboard)/jobs/[jobId]/page.tsx
@@ -7,6 +7,7 @@ import { Button } from "@/components/ui/button";
 import { Card, CardContent, CardDescription, CardHeader, CardTitle } from "@/components/ui/card";
 import { listJobFiles } from "@/lib/appwrite/job-file-queries";
 import { listJobHistory } from "@/lib/appwrite/job-history-queries";
+import { toPlain } from "@/lib/appwrite/serialize";
 import {
   JOB_STATUS_LABELS,
   JOB_STEP_LABELS,
@@ -57,7 +58,7 @@ export default async function JobDetailPage({
   let job: Job;
   try {
     const row = await tablesDB.getRow(DATABASE_ID, TABLES.jobs, jobId);
-    job = row as unknown as Job;
+    job = toPlain(row as unknown as Job);
   } catch {
     notFound();
   }
diff --git a/src/lib/appwrite/connection-queries.ts b/src/lib/appwrite/connection-queries.ts
index 31ad8f5..91185f7 100644
--- a/src/lib/appwrite/connection-queries.ts
+++ b/src/lib/appwrite/connection-queries.ts
@@ -10,6 +10,7 @@ import {
   type TenantSettings,
 } from "./schema";
 import { createAdminClient } from "./server";
+import { toPlain } from "./serialize";
 
 export type CounterpartTenant = {
   tenantId: string;
@@ -54,10 +55,12 @@ async function enrich(
     new Set(rows.map((r) => counterpartTenantId(r, selfTenantId))),
   );
   const map = await fetchCounterparts(counterpartIds);
-  return rows.map((r) => ({
-    ...r,
-    counterpart: map.get(counterpartTenantId(r, selfTenantId)) ?? null,
-  }));
+  return toPlain(
+    rows.map((r) => ({
+      ...r,
+      counterpart: map.get(counterpartTenantId(r, selfTenantId)) ?? null,
+    })),
+  );
 }
 
 async function listConnectionsByStatus(
diff --git a/src/lib/appwrite/dashboard-queries.ts b/src/lib/appwrite/dashboard-queries.ts
index 2f61a30..a203e3c 100644
--- a/src/lib/appwrite/dashboard-queries.ts
+++ b/src/lib/appwrite/dashboard-queries.ts
@@ -12,6 +12,7 @@ import {
   type TenantSettings,
 } from "./schema";
 import { createAdminClient } from "./server";
+import { toPlain } from "./serialize";
 
 export type DashboardJob = Job & {
   counterpartName: string | null;
@@ -140,7 +141,7 @@ export async function getDashboardData(
     if (e.type === "payable") payablePending += e.amount;
   }
 
-  return {
+  return toPlain({
     openJobsCount: openJobsRes.total,
     pendingActionCount: pendingActionRes.total,
     unreadCount: unreadRes.total,
@@ -154,5 +155,5 @@ export async function getDashboardData(
         counterpartMap.get(isLab ? j.clinicTenantId : j.labTenantId) ?? null,
     })),
     recentNotifications: notifRes.rows as unknown as Notification[],
-  };
+  });
 }
diff --git a/src/lib/appwrite/finance-queries.ts b/src/lib/appwrite/finance-queries.ts
index 1df10cd..e8b980f 100644
--- a/src/lib/appwrite/finance-queries.ts
+++ b/src/lib/appwrite/finance-queries.ts
@@ -10,6 +10,7 @@ import {
   type TenantSettings,
 } from "./schema";
 import { createAdminClient } from "./server";
+import { toPlain } from "./serialize";
 
 export type FinanceCounterpart = {
   tenantId: string;
@@ -40,7 +41,7 @@ export async function listFinanceEntries(
     new Set(rows.map((r) => r.counterpartTenantId).filter((v): v is string => Boolean(v))),
   );
   if (counterpartIds.length === 0) {
-    return rows.map((r) => ({ ...r, counterpart: null }));
+    return toPlain(rows.map((r) => ({ ...r, counterpart: null })));
   }
 
   const counterpartsRes = await tablesDB.listRows({
@@ -57,10 +58,12 @@ export async function listFinanceEntries(
     });
   }
 
-  return rows.map((r) => ({
-    ...r,
-    counterpart: r.counterpartTenantId ? map.get(r.counterpartTenantId) ?? null : null,
-  }));
+  return toPlain(
+    rows.map((r) => ({
+      ...r,
+      counterpart: r.counterpartTenantId ? map.get(r.counterpartTenantId) ?? null : null,
+    })),
+  );
 }
 
 export function summarizeFinance(
diff --git a/src/lib/appwrite/job-file-queries.ts b/src/lib/appwrite/job-file-queries.ts
index b43113e..5884000 100644
--- a/src/lib/appwrite/job-file-queries.ts
+++ b/src/lib/appwrite/job-file-queries.ts
@@ -4,6 +4,7 @@ import { Query } from "node-appwrite";
 
 import { BUCKETS, DATABASE_ID, TABLES, type JobFile } from "./schema";
 import { createAdminClient } from "./server";
+import { toPlain } from "./serialize";
 import { getFileViewUrl } from "./storage";
 
 export type JobFileWithUrl = JobFile & {
@@ -22,8 +23,10 @@ export async function listJobFiles(jobId: string): Promise<JobFileWithUrl[]> {
     ],
   });
   const rows = result.rows as unknown as JobFile[];
-  return rows.map((r) => ({
-    ...r,
-    url: getFileViewUrl(BUCKETS.jobFiles, r.fileId),
-  }));
+  return toPlain(
+    rows.map((r) => ({
+      ...r,
+      url: getFileViewUrl(BUCKETS.jobFiles, r.fileId),
+    })),
+  );
 }
diff --git a/src/lib/appwrite/job-history-queries.ts b/src/lib/appwrite/job-history-queries.ts
index 0256cf7..0cd334c 100644
--- a/src/lib/appwrite/job-history-queries.ts
+++ b/src/lib/appwrite/job-history-queries.ts
@@ -4,6 +4,7 @@ import { Query } from "node-appwrite";
 
 import { DATABASE_ID, TABLES, type JobStatusHistory } from "./schema";
 import { createAdminClient } from "./server";
+import { toPlain } from "./serialize";
 
 export async function listJobHistory(jobId: string): Promise<JobStatusHistory[]> {
   const { tablesDB } = createAdminClient();
@@ -16,5 +17,5 @@ export async function listJobHistory(jobId: string): Promise<JobStatusHistory[]>
       Query.limit(100),
     ],
   });
-  return result.rows as unknown as JobStatusHistory[];
+  return toPlain(result.rows as unknown as JobStatusHistory[]);
 }
diff --git a/src/lib/appwrite/job-queries.ts b/src/lib/appwrite/job-queries.ts
index cea378b..2dc8e13 100644
--- a/src/lib/appwrite/job-queries.ts
+++ b/src/lib/appwrite/job-queries.ts
@@ -10,6 +10,7 @@ import {
   type TenantSettings,
 } from "./schema";
 import { createAdminClient } from "./server";
+import { toPlain } from "./serialize";
 
 export type JobCounterpart = {
   tenantId: string;
@@ -58,7 +59,7 @@ export async function listInboundJobs(labTenantId: string): Promise<JobWithCount
   });
   const jobs = result.rows as unknown as Job[];
   const map = await fetchTenants(Array.from(new Set(jobs.map((j) => j.clinicTenantId))));
-  return jobs.map((j) => enrichJob(j, j.clinicTenantId, map));
+  return toPlain(jobs.map((j) => enrichJob(j, j.clinicTenantId, map)));
 }
 
 /** Outbound for a clinic tenant — jobs the clinic has sent. */
@@ -75,7 +76,7 @@ export async function listOutboundJobs(clinicTenantId: string): Promise<JobWithC
   });
   const jobs = result.rows as unknown as Job[];
   const map = await fetchTenants(Array.from(new Set(jobs.map((j) => j.labTenantId))));
-  return jobs.map((j) => enrichJob(j, j.labTenantId, map));
+  return toPlain(jobs.map((j) => enrichJob(j, j.labTenantId, map)));
 }
 
 /** For clinic's "Yeni İş Yayınla" form: list approved labs they can send to. */
@@ -96,7 +97,9 @@ export async function listApprovedLabsForClinic(
     (r) => r.labTenantId,
   );
   const map = await fetchTenants(labIds);
-  return labIds
-    .map((id) => map.get(id))
-    .filter((v): v is JobCounterpart => Boolean(v));
+  return toPlain(
+    labIds
+      .map((id) => map.get(id))
+      .filter((v): v is JobCounterpart => Boolean(v)),
+  );
 }
diff --git a/src/lib/appwrite/notification-helpers.ts b/src/lib/appwrite/notification-helpers.ts
index e11ab4a..8c67e9a 100644
--- a/src/lib/appwrite/notification-helpers.ts
+++ b/src/lib/appwrite/notification-helpers.ts
@@ -4,6 +4,7 @@ import { ID, Permission, Query, Role } from "node-appwrite";
 
 import { DATABASE_ID, TABLES, type Notification } from "./schema";
 import { createAdminClient } from "./server";
+import { toPlain } from "./serialize";
 
 type CreateNotificationInput = {
   tenantId: string;
@@ -76,5 +77,5 @@ export async function listNotifications(
       Query.limit(limit),
     ],
   });
-  return result.rows as unknown as Notification[];
+  return toPlain(result.rows as unknown as Notification[]);
 }
diff --git a/src/lib/appwrite/prosthetic-queries.ts b/src/lib/appwrite/prosthetic-queries.ts
index bdbc6fc..8df77fd 100644
--- a/src/lib/appwrite/prosthetic-queries.ts
+++ b/src/lib/appwrite/prosthetic-queries.ts
@@ -4,6 +4,7 @@ import { Query } from "node-appwrite";
 
 import { DATABASE_ID, TABLES, type Prosthetic } from "./schema";
 import { createAdminClient } from "./server";
+import { toPlain } from "./serialize";
 
 export async function listProsthetics(tenantId: string): Promise<Prosthetic[]> {
   const { tablesDB } = createAdminClient();
@@ -16,7 +17,7 @@ export async function listProsthetics(tenantId: string): Promise<Prosthetic[]> {
       Query.limit(200),
     ],
   });
-  return result.rows as unknown as Prosthetic[];
+  return toPlain(result.rows as unknown as Prosthetic[]);
 }
 
 export async function listActiveProsthetics(tenantId: string): Promise<Prosthetic[]> {
@@ -31,5 +32,5 @@ export async function listActiveProsthetics(tenantId: string): Promise<Prostheti
       Query.limit(200),
     ],
   });
-  return result.rows as unknown as Prosthetic[];
+  return toPlain(result.rows as unknown as Prosthetic[]);
 }
diff --git a/src/lib/appwrite/serialize.ts b/src/lib/appwrite/serialize.ts
new file mode 100644
index 0000000..7838ba0
--- /dev/null
+++ b/src/lib/appwrite/serialize.ts
@@ -0,0 +1,15 @@
+import "server-only";
+
+/**
+ * Appwrite SDK returns row objects that carry a non-plain prototype with
+ * helpers like `toString`. Next.js's server-to-client serializer rejects
+ * those. Use this helper to flatten any row (or row array) into a plain
+ * object before crossing the boundary or returning from a server fn.
+ *
+ * JSON-roundtripping is deliberate: cheap, deterministic, drops every
+ * non-serialisable field. Anything that needs to survive (Dates, Buffers)
+ * has to be converted explicitly by the caller anyway.
+ */
+export function toPlain<T>(value: T): T {
+  return JSON.parse(JSON.stringify(value)) as T;
+}