diff --git a/src/server/routes/api/accounts.manual-models.test.ts b/src/server/routes/api/accounts.manual-models.test.ts
index c2caae4..23aa561 100644
--- a/src/server/routes/api/accounts.manual-models.test.ts
+++ b/src/server/routes/api/accounts.manual-models.test.ts
@@ -130,4 +130,16 @@ describe('accounts manual models endpoint', () => {
 
     expect(response.statusCode).toBe(404);
   });
+
+  it('returns validation error for empty models array', async () => {
+    const response = await app.inject({
+      method: 'POST',
+      url: '/api/accounts/1/models/manual',
+      payload: {
+        models: [],
+      },
+    });
+
+    expect(response.statusCode).toBe(400);
+  });
 });
diff --git a/src/server/routes/api/accounts.skip-model-fetch.test.ts b/src/server/routes/api/accounts.skip-model-fetch.test.ts
index b0ce3dd..d8b6bd1 100644
--- a/src/server/routes/api/accounts.skip-model-fetch.test.ts
+++ b/src/server/routes/api/accounts.skip-model-fetch.test.ts
@@ -1,6 +1,6 @@
 import Fastify, { type FastifyInstance } from 'fastify';
 import { afterAll, beforeAll, beforeEach, describe, expect, it, vi } from 'vitest';
-import { mkdtempSync } from 'node:fs';
+import { mkdtempSync, rmSync } from 'node:fs';
 import { tmpdir } from 'node:os';
 import { join } from 'node:path';
 
@@ -50,6 +50,11 @@ describe('accounts skipModelFetch behavior', () => {
 
   afterAll(async () => {
     await app.close();
+    if (dataDir) {
+      try {
+        rmSync(dataDir, { recursive: true, force: true });
+      } catch { }
+    }
     delete process.env.DATA_DIR;
   });
 
diff --git a/src/server/routes/api/accounts.ts b/src/server/routes/api/accounts.ts
index 341058c..ebaa94f 100644
--- a/src/server/routes/api/accounts.ts
+++ b/src/server/routes/api/accounts.ts
@@ -1432,30 +1432,32 @@ export async function accountsRoutes(app: FastifyInstance) {
     }
 
     try {
-      for (const modelName of normalizedModels) {
-        const existing = await db.select()
-          .from(schema.modelAvailability)
-          .where(and(eq(schema.modelAvailability.accountId, accountId), eq(schema.modelAvailability.modelName, modelName)))
-          .get();
+      await db.transaction(async (tx: any) => {
+        for (const modelName of normalizedModels) {
+          const existing = await tx.select()
+            .from(schema.modelAvailability)
+            .where(and(eq(schema.modelAvailability.accountId, accountId), eq(schema.modelAvailability.modelName, modelName)))
+            .get();
 
-        if (existing) {
-          if (!existing.available || !existing.isManual) {
-            await db.update(schema.modelAvailability)
-              .set({ available: true, latencyMs: null, isManual: true, checkedAt: new Date().toISOString() })
-              .where(eq(schema.modelAvailability.id, existing.id))
-              .run();
+          if (existing) {
+            if (!existing.available || !existing.isManual) {
+              await tx.update(schema.modelAvailability)
+                .set({ available: true, latencyMs: null, isManual: true, checkedAt: new Date().toISOString() })
+                .where(eq(schema.modelAvailability.id, existing.id))
+                .run();
+            }
+          } else {
+            await tx.insert(schema.modelAvailability).values({
+              accountId,
+              modelName,
+              available: true,
+              isManual: true,
+              latencyMs: null,
+              checkedAt: new Date().toISOString(),
+            }).run();
           }
-        } else {
-          await db.insert(schema.modelAvailability).values({
-            accountId,
-            modelName,
-            available: true,
-            isManual: true,
-            latencyMs: null,
-            checkedAt: new Date().toISOString(),
-          }).run();
         }
-      }
+      });
 
       try {
         await rebuildTokenRoutesFromAvailability();
diff --git a/src/server/routes/proxy/models.test.ts b/src/server/routes/proxy/models.test.ts
index 158e2b5..fad0be3 100644
--- a/src/server/routes/proxy/models.test.ts
+++ b/src/server/routes/proxy/models.test.ts
@@ -354,7 +354,7 @@ describe('/v1/models route', () => {
 
     await db.insert(schema.downstreamApiKeys).values({
       name: 'search-key',
-      key: 'change-me-proxy-sk-token',
+      key: 'sk-search-key',
       enabled: true,
     }).run();
 
@@ -362,7 +362,7 @@ describe('/v1/models route', () => {
       method: 'GET',
       url: '/v1/models',
       headers: {
-        authorization: 'Bearer change-me-proxy-sk-token',
+        authorization: 'Bearer sk-search-key',
       },
     });