diff --git a/docs/self-hosted-redesign/phase-9-mobile-api.md b/docs/self-hosted-redesign/phase-9-mobile-api.md
index c91e0db..1b46011 100644
--- a/docs/self-hosted-redesign/phase-9-mobile-api.md
+++ b/docs/self-hosted-redesign/phase-9-mobile-api.md
@@ -2,7 +2,7 @@
 title: Faz 9 — Mobil API, Instance Discovery ve Localization Sözleşmesi
 description: React Native istemcileri için discovery, API v1, metadata, localization, capability, sürümleme ve güvenlik sınırı.
 status: completed
-last_updated: 2026-07-21
+last_updated: 2026-07-29
 ---
 
 # Faz 9 — Mobil API ve instance discovery
@@ -130,7 +130,26 @@ Mevcut hata kodları:
 - Capability listesi
 - Discovery, API, health ve me linkleri
 
-Capability kaydı:
+Mobil istemcilerin basit ve kararlı feature kontrolü yapabilmesi için
+`capabilities`, yalnız kullanılabilir yetenek ID'lerini string listesi olarak
+döndürür:
+
+```json
+{
+  "capabilities": [
+    "mobile-v1",
+    "instance.discovery",
+    "instance.branding"
+  ]
+}
+```
+
+`mobile-v1`, instance'ın temel Neta mobil discovery, metadata, health,
+localization ve session sözleşmesini sunduğunu belirtir. Planlanmış fakat henüz
+kullanılamayan yetenekler bu string listesine girmez.
+
+Sürüm, durum ve erişim bilgisine ihtiyaç duyan istemciler aynı yanıttaki
+`capabilityDetails` alanını kullanır. Ayrıntılı capability kaydı:
 
 ```json
 {
@@ -141,7 +160,7 @@ Capability kaydı:
 }
 ```
 
-İstemci bilinmeyen capability ID ve alanlarını yok saymalıdır. `status=planned`, endpoint'in kullanılabilir olduğu anlamına gelmez.
+İstemci bilinmeyen capability ID ve alanlarını yok saymalıdır. `status=planned`, endpoint'in kullanılabilir olduğu anlamına gelmez. Feature gating için string `capabilities` listesi; yönetim, debug ve ileri seviye sürüm kontrolü için `capabilityDetails` kullanılır.
 
 `instance.workspaceName` kullanıcıya gösterilecek firma/freelance çalışma alanı adıdır.
 `instance.metaTitle` web metadata başlığıdır. `branding.lightLogoUrl`,
@@ -185,6 +204,7 @@ portal varsayılanı bu endpoint ile değişmez.
 
 İlk capability seti:
 
+- `mobile-v1`
 - `instance.discovery`
 - `instance.branding`
 - `instance.localization`
diff --git a/scripts/i18n-phase8-smoke.ts b/scripts/i18n-phase8-smoke.ts
index a4ae67d..3b06304 100644
--- a/scripts/i18n-phase8-smoke.ts
+++ b/scripts/i18n-phase8-smoke.ts
@@ -7,7 +7,7 @@ import {
   type ApiLocalizationMetadata,
 } from "../server/api/v1/localization";
 import {
-  NETA_CAPABILITIES,
+  NETA_CAPABILITY_DETAILS,
   type NetaLocalizedResponse,
   type NetaTranslationMutationShape,
 } from "../server/api/v1/contracts";
@@ -89,7 +89,7 @@ assert.equal(contract.responseContract.localizedResourceField, "localized");
 assert.equal(contract.responseContract.translationsField, "translations");
 
 assert.equal(
-  NETA_CAPABILITIES.some((capability) => capability.id === "instance.localization" && capability.status === "available"),
+  NETA_CAPABILITY_DETAILS.some((capability) => capability.id === "instance.localization" && capability.status === "available"),
   true,
 );
 
diff --git a/scripts/phase1-auth-smoke.mjs b/scripts/phase1-auth-smoke.mjs
index eeed3c1..d7f55b4 100644
--- a/scripts/phase1-auth-smoke.mjs
+++ b/scripts/phase1-auth-smoke.mjs
@@ -102,8 +102,18 @@ try {
   assert.equal(publicMeta.payload.data.client.minimumSupportedVersion, "1.2.3-smoke.1");
   assert.equal(publicMeta.payload.data.links.me, `${baseUrl}/api/v1/me`);
   assert.deepEqual(publicMeta.payload.data.client.platforms, ["ios", "android"]);
+  assert.equal(
+    publicMeta.payload.data.capabilities.includes("mobile-v1"),
+    true,
+    "Public metadata must advertise the base mobile client contract",
+  );
+  assert.equal(
+    discovery.capabilities.includes("mobile-v1"),
+    true,
+    "Discovery must advertise the base mobile client contract",
+  );
   assert.deepEqual(
-    publicMeta.payload.data.capabilities.find(
+    publicMeta.payload.data.capabilityDetails.find(
       (capability) => capability.id === "auth.device-pairing",
     ),
     {
@@ -337,7 +347,7 @@ try {
     assert.equal(invalidChatRequest.headers.get("x-neta-error-code"), "VALIDATION_ERROR");
     assert.match(
       await invalidChatRequest.text(),
-      /"messages" alanı boş olamaz/,
+      /^chat\.errors\.invalidDetailed\|messages: too_small$/,
       "Chat validation errors must identify the invalid request field",
     );
 
@@ -353,7 +363,7 @@ try {
     assert.equal(missingChatSettings.status, 400, "Missing AI key must fail: /api/chat");
     assert.match(
       await missingChatSettings.text(),
-      /AI sağlayıcısı ve API anahtarı/,
+      /^chat\.errors\.invalidDetailed\|missing_settings$/,
       "The AI SDK v6 transport envelope must pass request validation and reach provider settings",
     );
     assert.equal(
diff --git a/scripts/phase9-api-boundary.mjs b/scripts/phase9-api-boundary.mjs
index 3aea14f..c903b64 100644
--- a/scripts/phase9-api-boundary.mjs
+++ b/scripts/phase9-api-boundary.mjs
@@ -18,6 +18,8 @@ for (const value of [
   'NETA_PROTOCOL = "neta"',
   "NETA_DISCOVERY_VERSION = 1",
   'NETA_API_VERSION = "1"',
+  'id: "mobile-v1"',
+  "NETA_CAPABILITY_DETAILS",
   '"instance.localization"',
   '"auth.device-pairing"',
   'status: "planned"',
diff --git a/server/api/v1/contracts.ts b/server/api/v1/contracts.ts
index 946d39a..c009046 100644
--- a/server/api/v1/contracts.ts
+++ b/server/api/v1/contracts.ts
@@ -30,7 +30,8 @@ export type NetaTranslationMutationShape = Record<
   Record<string, string | null>
 >;
 
-export const NETA_CAPABILITIES = [
+export const NETA_CAPABILITY_DETAILS = [
+  { id: "mobile-v1", version: 1, status: "available", access: "public" },
   { id: "instance.discovery", version: 1, status: "available", access: "public" },
   { id: "instance.branding", version: 1, status: "available", access: "public" },
   { id: "instance.localization", version: 1, status: "available", access: "public" },
@@ -42,6 +43,10 @@ export const NETA_CAPABILITIES = [
   { id: "auth.device-pairing", version: 1, status: "planned", access: "freelancer" },
 ] as const satisfies readonly NetaCapability[];
 
+export const NETA_CAPABILITIES = NETA_CAPABILITY_DETAILS
+  .filter((capability) => capability.status === "available")
+  .map((capability) => capability.id);
+
 export type NetaDiscoveryDocument = {
   protocol: typeof NETA_PROTOCOL;
   discoveryVersion: typeof NETA_DISCOVERY_VERSION;
@@ -70,7 +75,8 @@ export type NetaDiscoveryDocument = {
     }>;
     catalogVersion: number;
   };
-  capabilities: readonly NetaCapability[];
+  capabilities: readonly string[];
+  capabilityDetails: readonly NetaCapability[];
 };
 
 export type NetaInstanceMetadata = {
@@ -136,7 +142,8 @@ export type NetaInstanceMetadata = {
     sessionMethod: "better-auth-cookie";
     devicePairing: "planned";
   };
-  capabilities: readonly NetaCapability[];
+  capabilities: readonly string[];
+  capabilityDetails: readonly NetaCapability[];
   links: {
     discovery: string;
     apiBase: string;
@@ -189,6 +196,7 @@ export function buildDiscoveryDocument(
       catalogVersion: input.localization.catalogVersion,
     },
     capabilities: NETA_CAPABILITIES,
+    capabilityDetails: NETA_CAPABILITY_DETAILS,
   };
 }
 
@@ -259,6 +267,7 @@ export function buildInstanceMetadata(
       devicePairing: "planned",
     },
     capabilities: NETA_CAPABILITIES,
+    capabilityDetails: NETA_CAPABILITY_DETAILS,
     links: {
       discovery: absoluteUrl(input.appUrl, "/.well-known/neta"),
       apiBase: absoluteUrl(input.appUrl, NETA_API_BASE_PATH),