diff --git a/src/types-drift-check.ts b/src/types-drift-check.ts
new file mode 100644
index 0000000..891ffca
--- /dev/null
+++ b/src/types-drift-check.ts
@@ -0,0 +1,15 @@
+/**
+ * Compile-time check: the hand-written types/index.d.ts must stay in sync
+ * with the source StoryAPI interface.  If this file fails to compile,
+ * the published types have drifted from the implementation.
+ *
+ * Run: npx tsc --noEmit
+ */
+import type { StoryAPI as SourceAPI } from './story-api';
+import type { StoryAPI as PublishedAPI } from '../types/index';
+
+// Both directions — if either fails, the types have drifted.
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+const _sourceToPublished: PublishedAPI = {} as SourceAPI;
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+const _publishedToSource: SourceAPI = {} as PublishedAPI;
diff --git a/types/index.d.ts b/types/index.d.ts
index 32f7f24..ac2d925 100644
--- a/types/index.d.ts
+++ b/types/index.d.ts
@@ -14,6 +14,7 @@ export interface HistoryMoment {
   passage: string;
   variables: Record<string, unknown>;
   timestamp: number;
+  prng?: { seed: string; pull: number } | null;
 }
 
 /**
@@ -27,6 +28,7 @@ export interface SavePayload {
   historyIndex: number;
   visitCounts?: Record<string, number>;
   renderCounts?: Record<string, number>;
+  prng?: { seed: string; pull: number } | null;
 }
 
 /**
@@ -79,6 +81,9 @@ export interface SettingsAPI {
   addList(name: string, config: ListConfig): void;
   addRange(name: string, config: RangeConfig): void;
   get(name: string): unknown;
+  getToggle(name: string): boolean;
+  getList(name: string): string;
+  getRange(name: string): number;
   set(name: string, value: unknown): void;
   getAll(): Record<string, unknown>;
   getDefinitions(): Map<string, SettingDef>;
@@ -102,6 +107,238 @@ export interface Passage {
   content: string;
 }
 
+/**
+ * Map of story event names to their callback signatures.
+ * @see {@link ../../src/event-emitter.ts} for the implementation.
+ */
+export interface StoryEventMap {
+  storyinit: () => void;
+  beforerestart: () => void;
+  actionsChanged: () => void;
+  variableChanged: (
+    changed: Record<string, { from: unknown; to: unknown }>,
+  ) => void;
+  beforesave: (
+    slot: string | undefined,
+    custom: Record<string, unknown> | undefined,
+  ) => void;
+  aftersave: (slot: string | undefined) => void;
+  beforeload: (slot: string | undefined) => void;
+  afterload: (slot: string | undefined) => void;
+  beforenavigate: (passageName: string) => void;
+  afternavigate: (to: string, from: string) => void;
+}
+
+/** Event name that can be passed to `Story.on()`. */
+export type StoryEvent = keyof StoryEventMap;
+
+/** Callback type for a given story event. */
+export type StoryEventCallback<E extends StoryEvent> = StoryEventMap[E];
+
+/** Transition animation type. */
+export type TransitionType = 'none' | 'fade' | 'fade-through' | 'crossfade';
+
+/**
+ * Configuration for passage transitions.
+ * @see {@link ../../src/transition.ts} for the implementation.
+ */
+export interface TransitionConfig {
+  type: TransitionType;
+  duration?: number;
+  pause?: number;
+}
+
+/**
+ * Options for `Story.watch()` trigger registration.
+ * @see {@link ../../src/triggers.ts} for the implementation.
+ */
+export interface WatchOptions {
+  goto?: string;
+  dialog?: string;
+  run?: string;
+  once?: boolean;
+  name?: string;
+  priority?: number;
+}
+
+/** Type of interactive action registered by a macro. */
+export type ActionType =
+  | 'link'
+  | 'button'
+  | 'cycle'
+  | 'textbox'
+  | 'numberbox'
+  | 'textarea'
+  | 'checkbox'
+  | 'radiobutton'
+  | 'listbox'
+  | 'back'
+  | 'forward'
+  | 'restart'
+  | 'save'
+  | 'load'
+  | 'dialog';
+
+/**
+ * A registered interactive action (link, button, input, etc.).
+ * @see {@link ../../src/action-registry.ts} for the implementation.
+ */
+export interface StoryAction {
+  id: string;
+  type: ActionType;
+  label: string;
+  target?: string;
+  variable?: string;
+  options?: string[];
+  value?: unknown;
+  disabled?: boolean;
+  perform: (value?: unknown) => void;
+}
+
+/**
+ * Storage usage information returned by `Story.storage.getInfo()`.
+ * @see {@link ../../src/saves/types.ts} for the implementation.
+ */
+export interface StorageInfo {
+  saveCount: number;
+  playthroughCount: number;
+  totalBytes: number;
+  backend: 'indexeddb' | 'localstorage' | 'memory';
+}
+
+/**
+ * Browser storage quota estimate returned by `Story.storage.getQuota()`.
+ * @see {@link ../../src/saves/types.ts} for the implementation.
+ */
+export interface StorageQuota {
+  usage: number;
+  quota: number;
+  estimateSupported: boolean;
+}
+
+/**
+ * Parameter metadata for a macro definition.
+ * @see {@link ../../src/registry.ts} for the implementation.
+ */
+export interface ParameterDef {
+  name: string;
+  required?: boolean;
+  description?: string;
+}
+
+/**
+ * Metadata about a registered macro, returned by `Story.getMacroRegistry()`.
+ * @see {@link ../../src/registry.ts} for the implementation.
+ */
+export interface MacroMetadata {
+  name: string;
+  block: boolean;
+  subMacros: string[];
+  storeVar?: boolean;
+  interpolate?: boolean;
+  merged?: boolean;
+  source: 'builtin' | 'user';
+  description?: string;
+  parameters?: ParameterDef[];
+}
+
+/**
+ * Props passed to a macro's render function.
+ * @see {@link ../../src/registry.ts} for the implementation.
+ */
+export interface MacroProps {
+  rawArgs: string;
+  className?: string;
+  id?: string;
+  children?: any[];
+  branches?: Array<{
+    rawArgs: string;
+    className?: string;
+    id?: string;
+    children: any[];
+  }>;
+}
+
+/**
+ * Options for registering an interactive action via `ctx.useAction`.
+ * @see {@link ../../src/hooks/use-action.ts} for the implementation.
+ */
+export interface UseActionOptions {
+  type: ActionType;
+  key: string;
+  authorId?: string;
+  label: string;
+  target?: string;
+  variable?: string;
+  options?: string[];
+  value?: unknown;
+  disabled?: boolean;
+  perform: (value?: unknown) => void;
+}
+
+/**
+ * Context object passed to a macro's render function alongside props.
+ * Internal Preact/AST types are represented as `any` since consumers
+ * may not have Preact type definitions installed.
+ * @see {@link ../../src/define-macro.ts} for the implementation.
+ */
+export interface MacroContext {
+  className?: string;
+  id?: string;
+  resolve?: (s: string | undefined) => string | undefined;
+  cls: string;
+  mutate: (code: string) => void;
+  update: (key: string, value: unknown) => void;
+  getValues: () => Record<string, unknown>;
+  merged?: readonly [
+    Record<string, unknown>,
+    Record<string, unknown>,
+    Record<string, unknown>,
+  ];
+  varName?: string;
+  value?: unknown;
+  setValue?: (value: unknown) => void;
+  getValue?: () => unknown;
+  evaluate?: (expr: string) => unknown;
+  collectText: (nodes: any[]) => string;
+  sourceLocation: () => string;
+  parseVarArgs: (rawArgs: string) => { varName: string; placeholder: string };
+  extractOptions: (children: any[]) => string[];
+  wrap: (content: any) => any;
+  useAction: (opts: UseActionOptions) => string;
+  h: (type: any, props: any, ...children: any[]) => any;
+  renderNodes: (
+    nodes: any[],
+    options?: { nobr?: boolean; locals?: Record<string, unknown> },
+  ) => any;
+  renderInlineNodes: (nodes: any[]) => any;
+  hooks: {
+    useState: any;
+    useRef: any;
+    useEffect: any;
+    useLayoutEffect: any;
+    useCallback: any;
+    useMemo: any;
+    useContext: any;
+  };
+}
+
+/**
+ * Configuration object for `Story.defineMacro()`.
+ * @see {@link ../../src/define-macro.ts} for the implementation.
+ */
+export interface MacroDefinition {
+  name: string;
+  subMacros?: string[];
+  block?: boolean;
+  interpolate?: boolean;
+  merged?: boolean;
+  storeVar?: boolean;
+  description?: string;
+  parameters?: ParameterDef[];
+  render: (props: MacroProps, ctx: MacroContext) => any;
+}
+
 /**
  * Metadata about a save slot, returned by `getSaveInfo()` and `listSaves()`.
  * @see {@link ../../src/saves/types.ts} for the implementation.
@@ -166,10 +403,10 @@ export interface StoryAPI {
   deleteSave(slot?: string): void;
 
   /** Return the number of times a passage has been visited. */
-  visited(name: string): number;
+  visited(name?: string): number;
 
   /** Check if a passage has been visited at least once. */
-  hasVisited(name: string): boolean;
+  hasVisited(name?: string): boolean;
 
   /** Check if any of the given passages have been visited. */
   hasVisitedAny(...names: string[]): boolean;
@@ -178,10 +415,10 @@ export interface StoryAPI {
   hasVisitedAll(...names: string[]): boolean;
 
   /** Return the number of times a passage has been rendered. */
-  rendered(name: string): number;
+  rendered(name?: string): number;
 
   /** Check if a passage has been rendered at least once. */
-  hasRendered(name: string): boolean;
+  hasRendered(name?: string): boolean;
 
   /** Check if any of the given passages have been rendered. */
   hasRenderedAny(...names: string[]): boolean;
@@ -228,4 +465,95 @@ export interface StoryAPI {
 
   /** Check whether any dialog is currently open. */
   isDialogOpen(): boolean;
+
+  /** Register a class constructor for use in story expressions. */
+  registerClass(name: string, ctor: new (...args: any[]) => any): void;
+
+  /** Register a custom macro. */
+  defineMacro(config: MacroDefinition): void;
+
+  /** Return metadata for all registered macros. */
+  getMacroRegistry(): MacroMetadata[];
+
+  /** Storage management API. */
+  readonly storage: {
+    /** Get storage usage information (save count, byte size, backend type). */
+    getInfo(): Promise<StorageInfo>;
+    /** Get browser storage quota estimate. */
+    getQuota(): Promise<StorageQuota>;
+    /** Delete all saves for the current game. */
+    clearGameData(): Promise<void>;
+    /** Delete all Spindle data across all games. */
+    clearAllData(): Promise<void>;
+    /** Delete a specific playthrough and its saves. */
+    deletePlaythrough(playthroughId: string): Promise<void>;
+    /** The active storage backend. */
+    readonly backend: 'indexeddb' | 'localstorage' | 'memory';
+  };
+
+  /** Return all registered interactive actions. */
+  getActions(): StoryAction[];
+
+  /** Perform a registered action by ID. */
+  performAction(id: string, value?: unknown): void;
+
+  /** Subscribe to a story event. Returns an unsubscribe function. */
+  on<E extends StoryEvent>(
+    event: E,
+    callback: StoryEventCallback<E>,
+  ): () => void;
+
+  /** Wait for the next frame's actions to be registered, then return them. */
+  waitForActions(): Promise<StoryAction[]>;
+
+  /** Register a trigger that fires when a condition expression becomes truthy. Returns an unsubscribe function. */
+  watch(
+    condition: string,
+    callbackOrOptions: (() => void) | WatchOptions,
+  ): () => void;
+
+  /** Remove a named trigger registered with `watch()`. */
+  unwatch(name: string): void;
+
+  /** Enable or disable the `{nobr}` (no line breaks) rendering mode globally. */
+  setNobr(enabled: boolean): void;
+
+  /** Enable or disable the story stylesheet. */
+  setCSS(enabled: boolean): void;
+
+  /** Set the default passage transition. Pass `null` to clear. */
+  setTransition(config: TransitionConfig | null): void;
+
+  /** Set a one-time transition for the next navigation only. Pass `null` to clear. */
+  setNextTransition(config: TransitionConfig | null): void;
+
+  /** Defer initial passage rendering until `ready()` is called. */
+  deferRender(): void;
+
+  /** Unblock deferred rendering (call after `deferRender()`). */
+  ready(): void;
+
+  /** Return a random float in [0, 1). Uses the seeded PRNG if enabled, otherwise Math.random(). */
+  random(): number;
+
+  /** Return a random integer in [min, max] (inclusive). */
+  randomInt(min: number, max: number): number;
+
+  /** Story configuration. */
+  readonly config: {
+    /** Maximum number of history moments to retain. */
+    maxHistory: number;
+  };
+
+  /** Seedable pseudo-random number generator. */
+  readonly prng: {
+    /** Initialize the PRNG with an optional seed. */
+    init(seed?: string, useEntropy?: boolean): void;
+    /** Check whether the seeded PRNG is active. */
+    isEnabled(): boolean;
+    /** The current PRNG seed. */
+    readonly seed: string;
+    /** The number of values pulled from the current seed. */
+    readonly pull: number;
+  };
 }