diff --git a/src/auth/AuthService.ts b/src/auth/AuthService.ts
index 7e76cc5..41127d5 100644
--- a/src/auth/AuthService.ts
+++ b/src/auth/AuthService.ts
@@ -1,15 +1,15 @@
 /**
- * AuthService — device-based player authentication.
+ * AuthService — player authentication.
  *
- * Handles login via device ID (the primary auth flow for game clients),
- * logout (token clearing), and auth state observation.
+ * Handles login via device ID (the primary auth flow for game clients) or a
+ * custom backend webhook, logout (token clearing), and auth state observation.
  */
 
 import type { RudderContext } from '../core/context.js';
 import type { RemoteConfigShape } from '../state/RemoteConfigState.js';
 import { getOrCreateDeviceId } from '../device/DeviceId.js';
 import { api } from '../generated/api.js';
-import type { LoginViaDeviceResponse } from '../generated/auth.js';
+import type { LoginViaCustomResponse, LoginViaDeviceResponse } from '../generated/auth.js';
 
 export type AuthState = 'signed-in' | 'signed-out';
 
@@ -24,6 +24,17 @@ export interface LoginWithDeviceOptions {
   nickname?: string;
 }
 
+export interface LoginWithCustomOptions {
+  /** Arbitrary payload forwarded to the developer's custom auth webhook. */
+  customData: Record<string, unknown>;
+  /** Player's region code (default: "global"). */
+  region?: string;
+  /** Player's language code (default: "en"). */
+  language?: string;
+  /** Optional player nickname; omitted from the request when not set. */
+  nickname?: string;
+}
+
 export class AuthService<TConfig extends RemoteConfigShape = RemoteConfigShape> {
   private readonly listeners = new Set<AuthStateListener>();
   private state: AuthState;
@@ -81,6 +92,32 @@ export class AuthService<TConfig extends RemoteConfigShape = RemoteConfigShape>
     return response;
   }
 
+  /**
+   * Authenticates via the project's custom authorization webhook and returns
+   * access + refresh tokens.
+   *
+   * The payload is forwarded to the developer's backend; on success, tokens are
+   * saved to the client's TokenStore.
+   */
+  async loginWithCustom(options: LoginWithCustomOptions): Promise<LoginViaCustomResponse> {
+    const { customData, region = 'global', language = 'en', nickname } = options;
+    const response = await api.loginViaCustom(this.ctx, {
+      key: this.ctx.options.projectKey,
+      customData,
+      region,
+      language,
+      nickname,
+    });
+
+    this.ctx.options.tokenStore.saveTokens(
+      response.accessToken ?? '',
+      response.refreshToken ?? '',
+    );
+    await this.startRuntime();
+    this.setState('signed-in');
+    return response;
+  }
+
   /** Clears all stored tokens (logout). */
   logout(): void {
     this.ctx.options.tokenStore.clear();
diff --git a/src/generated/api.ts b/src/generated/api.ts
index 3168755..5b530e2 100644
--- a/src/generated/api.ts
+++ b/src/generated/api.ts
@@ -1,13 +1,13 @@
 // Code generated by apigen. DO NOT EDIT.
 
-import type { LoginViaDeviceRequest, LoginViaDeviceResponse, RefreshAccessTokenRequest, RefreshAccessTokenResponse } from './auth.js';
+import type { LoginViaCustomRequest, LoginViaCustomResponse, LoginViaDeviceRequest, LoginViaDeviceResponse, RefreshAccessTokenRequest, RefreshAccessTokenResponse } from './auth.js';
 import type { AddBattlePassXpRequest, AddBattlePassXpResponse, ClaimBattlePassRewardRequest, ClaimBattlePassRewardResponse, GetBattlePassProgressRequest, GetBattlePassProgressResponse, PurchaseBattlePassPremiumRequest, PurchaseBattlePassPremiumResponse } from './battlepass.js';
 import type { ListCatalogItemsResponse } from './catalog.js';
 import type { GetInventoryResponse } from './inventory.js';
 import type { GetRankingResponse, SubmitScoreRequest } from './leaderboards.js';
 import type { PlayerProfile } from './player.js';
 import type { GetProjectStorageResponse, UpdateProjectStorageRequest } from './project-storage.js';
-import type { ClaimQuestRequest, ClaimQuestResponse, ListQuestsRequest, ListQuestsResponse, ReportQuestProgressRequest, ReportQuestProgressResponse } from './quests.js';
+import type { ClaimQuestRequest, ClaimQuestResponse, ListQuestsResponse, ReportQuestProgressRequest, ReportQuestProgressResponse } from './quests.js';
 import type { ListRemoteConfigsResponse, RemoteConfig } from './remote-config.js';
 import type { GetScenarioRunRequest, GetScenarioRunResponse, HandleScenarioCallbackRequest, HandleScenarioCallbackResponse, TriggerScenarioRequest, TriggerScenarioResponse, UpdateScenarioCounterRequest, UpdateScenarioCounterResponse } from './scenarios.js';
 import type { GetStorageResponse, UpdateStorageRequest } from './storage.js';
@@ -131,9 +131,8 @@ export const api = {
 
   listQuests: (
     t: Transport,
-    body: ListQuestsRequest,
   ): Promise<ListQuestsResponse> =>
-    t.request<ListQuestsResponse>('POST', '/sdk/v1/quests/list', body),
+    t.request<ListQuestsResponse>('POST', '/sdk/v1/quests/list'),
 
   listSdkRemoteConfigs: (
     t: Transport,
@@ -145,6 +144,12 @@ export const api = {
   ): Promise<ListStoresResponse> =>
     t.request<ListStoresResponse>('GET', '/sdk/v1/stores'),
 
+  loginViaCustom: (
+    t: Transport,
+    body: LoginViaCustomRequest,
+  ): Promise<LoginViaCustomResponse> =>
+    t.request<LoginViaCustomResponse>('POST', '/sdk/v1/authorization/custom', body),
+
   loginViaDevice: (
     t: Transport,
     body: LoginViaDeviceRequest,
diff --git a/src/generated/auth.ts b/src/generated/auth.ts
index 3885fb1..ab2414a 100644
--- a/src/generated/auth.ts
+++ b/src/generated/auth.ts
@@ -1,5 +1,18 @@
 // Code generated by apigen. DO NOT EDIT.
 
+export interface LoginViaCustomRequest {
+  "customData"?: { [key: string]: unknown };
+  "key"?: string;
+  "language"?: string;
+  "nickname"?: string;
+  "region"?: string;
+}
+
+export interface LoginViaCustomResponse {
+  "accessToken"?: string;
+  "refreshToken"?: string;
+}
+
 export interface LoginViaDeviceRequest {
   "deviceId"?: string;
   "key"?: string;
diff --git a/src/generated/battlepass.ts b/src/generated/battlepass.ts
index 68c9d74..51917a2 100644
--- a/src/generated/battlepass.ts
+++ b/src/generated/battlepass.ts
@@ -1,6 +1,6 @@
 // Code generated by apigen. DO NOT EDIT.
 
-import type { ExecutionPlan } from './common.js';
+import type { ExecutionPlan, Reward } from './common.js';
 
 export interface AddBattlePassXpRequest {
   "amount"?: number;
@@ -18,24 +18,18 @@ export interface AddBattlePassXpResponse {
   "xp"?: number;
 }
 
-export interface BattlePassReward {
-  "amount"?: number;
-  "currency"?: string;
-  "itemId"?: string;
-}
-
 export interface ClaimBattlePassRewardRequest {
   "level"?: number;
   "nodeId"?: string;
   "runId"?: string;
   "scenarioId"?: string;
-  "track"?: string;
+  "track"?: "free" | "premium";
 }
 
 export interface ClaimBattlePassRewardResponse {
   "alreadyClaimed"?: boolean;
   "error"?: string;
-  "granted"?: BattlePassReward[];
+  "granted"?: Reward[];
   "success"?: boolean;
 }
 
diff --git a/src/generated/common.ts b/src/generated/common.ts
index 586986e..f18d0f0 100644
--- a/src/generated/common.ts
+++ b/src/generated/common.ts
@@ -13,6 +13,8 @@ export interface BoundaryNode {
 export interface ErrorResponse {
   "code"?: "early_completion" | "forbidden" | "level_not_reached" | "node_not_active" | "objectives_incomplete" | "run_expired" | "run_not_active" | "scenario_not_active" | "unknown_run";
   "error"?: string;
+  "index"?: number;
+  "playerId"?: string;
   "requestId"?: string;
 }
 
@@ -42,3 +44,9 @@ export interface PlanEdge {
   "targetHandle"?: string;
 }
 
+export interface Reward {
+  "amount"?: number;
+  "currency"?: string;
+  "itemId"?: string;
+}
+
diff --git a/src/generated/quests.ts b/src/generated/quests.ts
index 7f50342..43b1782 100644
--- a/src/generated/quests.ts
+++ b/src/generated/quests.ts
@@ -1,5 +1,7 @@
 // Code generated by apigen. DO NOT EDIT.
 
+import type { Reward } from './common.js';
+
 export interface ClaimQuestRequest {
   "questId"?: string;
 }
@@ -7,13 +9,10 @@ export interface ClaimQuestRequest {
 export interface ClaimQuestResponse {
   "alreadyClaimed"?: boolean;
   "error"?: string;
-  "granted"?: QuestReward[];
+  "granted"?: Reward[];
   "success"?: boolean;
 }
 
-export interface ListQuestsRequest {
-}
-
 export interface ListQuestsResponse {
   "quests"?: Quest[];
 }
@@ -22,8 +21,8 @@ export interface Quest {
   "id"?: string;
   "name"?: string;
   "objectives"?: QuestObjectiveProgress[];
-  "rewards"?: QuestReward[];
-  "status"?: string;
+  "rewards"?: Reward[];
+  "status"?: "active" | "claimed" | "completed";
 }
 
 export interface QuestObjectiveProgress {
@@ -34,12 +33,6 @@ export interface QuestObjectiveProgress {
   "target"?: number;
 }
 
-export interface QuestReward {
-  "amount"?: number;
-  "currency"?: string;
-  "itemId"?: string;
-}
-
 export interface ReportQuestProgressRequest {
   "amount"?: number;
   "metric"?: string;
diff --git a/src/generated/remote-config.ts b/src/generated/remote-config.ts
index 5023e90..7e2466d 100644
--- a/src/generated/remote-config.ts
+++ b/src/generated/remote-config.ts
@@ -14,6 +14,6 @@ export interface RemoteConfig {
   "projectId"?: string;
   "updatedAt"?: string;
   "value"?: string;
-  "valueType"?: string;
+  "valueType"?: "bool" | "float" | "int" | "json" | "string";
 }
 
diff --git a/src/generated/scenarios.ts b/src/generated/scenarios.ts
index bc9d143..e886378 100644
--- a/src/generated/scenarios.ts
+++ b/src/generated/scenarios.ts
@@ -9,7 +9,7 @@ export interface GetScenarioRunRequest {
 export interface GetScenarioRunResponse {
   "plan"?: ExecutionPlan;
   "runId"?: string;
-  "status"?: string;
+  "status"?: "active" | "completed" | "expired";
 }
 
 export interface HandleScenarioCallbackRequest {
diff --git a/src/index.ts b/src/index.ts
index fc791f4..917f12e 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -22,6 +22,7 @@ export type {
   AuthService,
   AuthState,
   AuthStateListener,
+  LoginWithCustomOptions,
   LoginWithDeviceOptions,
 } from './auth/AuthService.js';
 export type { LeaderboardsService, LeaderboardHandle } from './leaderboards/LeaderboardsService.js';
@@ -88,14 +89,13 @@ export type {
   ProjectStorageUpdateItem,
 } from './generated/project-storage.js';
 export type { RemoteConfig } from './generated/remote-config.js';
+export type { Reward } from './generated/common.js';
 export type {
   Quest,
   QuestObjectiveProgress,
-  QuestReward,
   ClaimQuestResponse,
 } from './generated/quests.js';
 export type {
-  BattlePassReward,
   ClaimedTier,
   AddBattlePassXpRequest,
   AddBattlePassXpResponse,