diff --git a/src/app/api/provider-models/route.ts b/src/app/api/provider-models/route.ts
index 3a0c1fafac..40c81a687b 100644
--- a/src/app/api/provider-models/route.ts
+++ b/src/app/api/provider-models/route.ts
@@ -370,7 +370,10 @@ export async function DELETE(request) {
     if (all === "true") {
       await replaceCustomModels(provider, [], { allowEmpty: true });
       const removedAliases = await deleteManagedAvailableModelAliasesForProvider(provider);
-      return Response.json({ cleared: true, aliasChanges: { removed: removedAliases } });
+      return Response.json({
+        cleared: true,
+        aliasChanges: { removed: removedAliases, assigned: [] },
+      });
     }
 
     if (!modelId) {
@@ -387,7 +390,7 @@ export async function DELETE(request) {
 
     const removed = await removeCustomModel(provider, modelId);
     const removedAliases = await deleteManagedAvailableModelAliases(provider, [modelId]);
-    return Response.json({ removed, aliasChanges: { removed: removedAliases } });
+    return Response.json({ removed, aliasChanges: { removed: removedAliases, assigned: [] } });
   } catch (error) {
     console.error("Error removing provider model:", error);
     return Response.json(
diff --git a/tests/unit/managed-available-models.test.ts b/tests/unit/managed-available-models.test.ts
index 21a41f86a2..2635867568 100644
--- a/tests/unit/managed-available-models.test.ts
+++ b/tests/unit/managed-available-models.test.ts
@@ -1,10 +1,39 @@
 import test from "node:test";
 import assert from "node:assert/strict";
+import fs from "node:fs";
+import os from "node:os";
+import path from "node:path";
 
+const TEST_DATA_DIR = fs.mkdtempSync(path.join(os.tmpdir(), "omniroute-managed-available-models-"));
+process.env.DATA_DIR = TEST_DATA_DIR;
+
+const core = await import("../../src/lib/db/core.ts");
+const modelsDb = await import("../../src/lib/db/models.ts");
+const localDb = await import("../../src/lib/localDb.ts");
 const { compatibleProviderSupportsModelImport, getCompatibleFallbackModels } =
   await import("../../src/lib/providers/managedAvailableModels.ts");
+const {
+  deleteManagedAvailableModelAliases,
+  deleteManagedAvailableModelAliasesForProvider,
+  syncManagedAvailableModelAliases,
+} = await import("../../src/lib/providerModels/managedAvailableModels.ts");
 const { getModelsByProviderId } = await import("../../src/shared/constants/models.ts");
 
+async function resetStorage() {
+  core.resetDbInstance();
+  fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true });
+  fs.mkdirSync(TEST_DATA_DIR, { recursive: true });
+}
+
+test.beforeEach(async () => {
+  await resetStorage();
+});
+
+test.after(() => {
+  core.resetDbInstance();
+  fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true });
+});
+
 test("CC compatible fallback models mirror the OAuth Claude Code registry list", () => {
   assert.deepEqual(
     getCompatibleFallbackModels("anthropic-compatible-cc-demo"),
@@ -20,3 +49,70 @@ test("OpenRouter keeps imported fallback models as its managed list source", ()
   const fallbackModels = [{ id: "openai/gpt-5" }, { id: "anthropic/claude-sonnet-4-6" }];
   assert.deepEqual(getCompatibleFallbackModels("openrouter", fallbackModels), fallbackModels);
 });
+
+test("hidden managed models do not create aliases during sync", async () => {
+  modelsDb.mergeModelCompatOverride("openrouter", "hidden/model", { isHidden: true });
+
+  const result = await syncManagedAvailableModelAliases("openrouter", ["hidden/model"]);
+  const aliases = await localDb.getModelAliases();
+
+  assert.deepEqual(result.assignedAliases, []);
+  assert.deepEqual(aliases, {});
+});
+
+test("deleteManagedAvailableModelAliases removes only aliases matching target full models", async () => {
+  await localDb.setModelAlias("target", "openrouter/xiaomi/mimo-v2.5-pro");
+  await localDb.setModelAlias("same-provider-other-model", "openrouter/xiaomi/mimo-v2.5-max");
+  await localDb.setModelAlias("other-provider", "openai/xiaomi/mimo-v2.5-pro");
+
+  const removed = await deleteManagedAvailableModelAliases("openrouter", ["xiaomi/mimo-v2.5-pro"]);
+  const aliases = await localDb.getModelAliases();
+
+  assert.deepEqual(removed, ["target"]);
+  assert.equal(aliases.target, undefined);
+  assert.equal(aliases["same-provider-other-model"], "openrouter/xiaomi/mimo-v2.5-max");
+  assert.equal(aliases["other-provider"], "openai/xiaomi/mimo-v2.5-pro");
+});
+
+test("deleteManagedAvailableModelAliasesForProvider removes provider-scoped aliases only", async () => {
+  await localDb.setModelAlias("router-a", "openrouter/provider/model-a");
+  await localDb.setModelAlias("router-b", "openrouter/provider/model-b");
+  await localDb.setModelAlias("openai-a", "openai/provider/model-a");
+  await localDb.setModelAlias("bare", "model-a");
+
+  const removed = await deleteManagedAvailableModelAliasesForProvider("openrouter");
+  const aliases = await localDb.getModelAliases();
+
+  assert.deepEqual(new Set(removed), new Set(["router-a", "router-b"]));
+  assert.equal(aliases["router-a"], undefined);
+  assert.equal(aliases["router-b"], undefined);
+  assert.equal(aliases["openai-a"], "openai/provider/model-a");
+  assert.equal(aliases.bare, "model-a");
+});
+
+test("unhidden managed models receive a fresh alias when sync reruns", async () => {
+  modelsDb.mergeModelCompatOverride("openrouter", "vendor/model", { isHidden: true });
+  await syncManagedAvailableModelAliases("openrouter", ["vendor/model"]);
+
+  modelsDb.mergeModelCompatOverride("openrouter", "vendor/model", { isHidden: false });
+  const result = await syncManagedAvailableModelAliases("openrouter", ["vendor/model"]);
+  const aliases = await localDb.getModelAliases();
+
+  assert.deepEqual(result.assignedAliases, ["model"]);
+  assert.equal(aliases.model, "openrouter/vendor/model");
+});
+
+test("managed alias helpers are no-ops for non-managed providers", async () => {
+  await localDb.setModelAlias("manual", "claude/custom-model");
+
+  const removedOne = await deleteManagedAvailableModelAliases("claude", ["custom-model"]);
+  const removedAll = await deleteManagedAvailableModelAliasesForProvider("claude");
+  const syncResult = await syncManagedAvailableModelAliases("claude", ["custom-model"]);
+  const aliases = await localDb.getModelAliases();
+
+  assert.deepEqual(removedOne, []);
+  assert.deepEqual(removedAll, []);
+  assert.deepEqual(syncResult.assignedAliases, []);
+  assert.deepEqual(syncResult.removedAliases, []);
+  assert.equal(aliases.manual, "claude/custom-model");
+});
diff --git a/tests/unit/managed-model-import.test.ts b/tests/unit/managed-model-import.test.ts
new file mode 100644
index 0000000000..84be9ff37c
--- /dev/null
+++ b/tests/unit/managed-model-import.test.ts
@@ -0,0 +1,66 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import fs from "node:fs";
+import os from "node:os";
+import path from "node:path";
+
+const TEST_DATA_DIR = fs.mkdtempSync(path.join(os.tmpdir(), "omniroute-managed-model-import-"));
+process.env.DATA_DIR = TEST_DATA_DIR;
+
+const core = await import("../../src/lib/db/core.ts");
+const modelsDb = await import("../../src/lib/db/models.ts");
+const localDb = await import("../../src/lib/localDb.ts");
+const { importManagedModels } = await import("../../src/lib/providerModels/managedModelImport.ts");
+
+async function resetStorage() {
+  core.resetDbInstance();
+  fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true });
+  fs.mkdirSync(TEST_DATA_DIR, { recursive: true });
+}
+
+test.beforeEach(async () => {
+  await resetStorage();
+});
+
+test.after(() => {
+  core.resetDbInstance();
+  fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true });
+});
+
+test("sync mode builds aliases from provider-level synced available models", async () => {
+  await modelsDb.replaceSyncedAvailableModelsForConnection("openrouter", "conn-a", [
+    { id: "shared/model-a", name: "Model A", source: "imported" },
+  ]);
+
+  await importManagedModels({
+    providerId: "openrouter",
+    connectionId: "conn-b",
+    mode: "sync",
+    fetchedModels: [{ id: "shared/model-b", name: "Model B" }],
+  });
+
+  const aliases = await localDb.getModelAliases();
+
+  assert.equal(aliases["model-a"], "openrouter/shared/model-a");
+  assert.equal(aliases["model-b"], "openrouter/shared/model-b");
+});
+
+test("merge mode builds aliases from discovered models without pruning missing provider aliases", async () => {
+  await modelsDb.replaceSyncedAvailableModelsForConnection("openrouter", "conn-a", [
+    { id: "shared/model-a", name: "Model A", source: "imported" },
+  ]);
+  await localDb.setModelAlias("existing", "openrouter/shared/existing");
+
+  await importManagedModels({
+    providerId: "openrouter",
+    connectionId: "conn-b",
+    mode: "merge",
+    fetchedModels: [{ id: "shared/model-b", name: "Model B" }],
+  });
+
+  const aliases = await localDb.getModelAliases();
+
+  assert.equal(aliases.existing, "openrouter/shared/existing");
+  assert.equal(aliases["model-a"], undefined);
+  assert.equal(aliases["model-b"], "openrouter/shared/model-b");
+});