diff --git a/lib/hexo/index.ts b/lib/hexo/index.ts
index edffd471a3..a7dd75df18 100644
--- a/lib/hexo/index.ts
+++ b/lib/hexo/index.ts
@@ -37,7 +37,7 @@ import loadDatabase from './load_database';
 import multiConfigPath from './multi_config_path';
 import { deepMerge, full_url_for } from 'hexo-util';
 import type Box from '../box';
-import type { NodeJSLikeCallback } from '../types';
+import type { AssetGenerator, LocalsType, NodeJSLikeCallback, NormalPageGenerator, NormalPostGenerator, PageGenerator, PostGenerator, SiteLocals } from '../types';
 
 let resolveSync; // = require('resolve');
 
@@ -50,7 +50,8 @@ const routeCache = new WeakMap();
 
 const castArray = (obj: any) => { return Array.isArray(obj) ? obj : [obj]; };
 
-const mergeCtxThemeConfig = ctx => {
+// eslint-disable-next-line no-use-before-define
+const mergeCtxThemeConfig = (ctx: Hexo) => {
   // Merge hexo.config.theme_config into hexo.theme.config before post rendering & generating
   // config.theme_config has "_config.[theme].yml" merged in load_theme_config.js
   if (ctx.config.theme_config) {
@@ -58,11 +59,12 @@ const mergeCtxThemeConfig = ctx => {
   }
 };
 
-const createLoadThemeRoute = function(generatorResult, locals, ctx) {
+// eslint-disable-next-line no-use-before-define
+const createLoadThemeRoute = function(generatorResult: NormalPageGenerator | NormalPostGenerator, locals: LocalsType, ctx: Hexo) {
   const { log, theme } = ctx;
   const { path, cache: useCache } = locals;
 
-  const layout = [...new Set(castArray(generatorResult.layout))];
+  const layout: string[] = [...new Set(castArray(generatorResult.layout))];
   const layoutLength = layout.length;
 
   // always use cache in fragment_cache
@@ -96,7 +98,7 @@ const createLoadThemeRoute = function(generatorResult, locals, ctx) {
   };
 };
 
-function debounce(func: () => void, wait: number) {
+function debounce(func: () => void, wait: number): () => void {
   let timeout: NodeJS.Timeout;
   return function() {
     clearTimeout(timeout);
@@ -342,9 +344,11 @@ class Hexo extends EventEmitter {
     });
   }
 
-  call(name: string, args: any, callback?: NodeJSLikeCallback<any>) {
+  call(name: string, callback?: NodeJSLikeCallback<any>): Promise<any>;
+  call(name: string, args: object, callback?: NodeJSLikeCallback<any>): Promise<any>;
+  call(name: string, args?: object | NodeJSLikeCallback<any>, callback?: NodeJSLikeCallback<any>): Promise<any> {
     if (!callback && typeof args === 'function') {
-      callback = args;
+      callback = args as NodeJSLikeCallback<any>;
       args = {};
     }
 
@@ -378,7 +382,7 @@ class Hexo extends EventEmitter {
 
   loadPlugin(path: string, callback?: NodeJSLikeCallback<any>): Promise<any> {
     return readFile(path).then(script => {
-      // Based on: https://github.com/joyent/node/blob/v0.10.33/src/node.js#L516
+      // Based on: https://github.com/nodejs/node-v0.x-archive/blob/v0.10.33/src/node.js#L516
       const module = new Module(path);
       module.filename = path;
       module.paths = Module._nodeModulePaths(path);
@@ -468,12 +472,10 @@ class Hexo extends EventEmitter {
   _generateLocals() {
     const { config, env, theme, theme_dir } = this;
     const ctx = { config: { url: this.config.url } };
-    const localsObj = this.locals.toObject();
+    const localsObj = this.locals.toObject() as SiteLocals;
 
     class Locals {
-      page: {
-        path: string;
-      };
+      page: NormalPageGenerator | NormalPostGenerator;
       path: string;
       url: string;
       config: object;
@@ -481,10 +483,10 @@ class Hexo extends EventEmitter {
       layout: string;
       env: any;
       view_dir: string;
-      site: object;
+      site: SiteLocals;
       cache?: boolean;
 
-      constructor(path: string, locals) {
+      constructor(path: string, locals: NormalPageGenerator | NormalPostGenerator) {
         this.page = { ...locals };
         if (this.page.path == null) this.page.path = path;
         this.path = path;
@@ -501,9 +503,9 @@ class Hexo extends EventEmitter {
     return Locals;
   }
 
-  _runGenerators(): Promise<any[]> {
+  _runGenerators(): Promise<(AssetGenerator | PostGenerator | PageGenerator)[]> {
     this.locals.invalidate();
-    const siteLocals = this.locals.toObject();
+    const siteLocals = this.locals.toObject() as SiteLocals;
     const generators = this.extend.generator.list();
     const { log } = this;
 
@@ -518,17 +520,19 @@ class Hexo extends EventEmitter {
     }, []);
   }
 
-  _routerRefresh(runningGenerators: Promise<any[]>, useCache: boolean): Promise<void> {
+  _routerRefresh(runningGenerators: Promise<(AssetGenerator | PostGenerator | PageGenerator)[]>, useCache: boolean): Promise<void> {
     const { route } = this;
     const routeList = route.list();
     const Locals = this._generateLocals();
     Locals.prototype.cache = useCache;
 
-    return runningGenerators.map(generatorResult => {
+    return runningGenerators.map((generatorResult: AssetGenerator | PostGenerator | PageGenerator) => {
       if (typeof generatorResult !== 'object' || generatorResult.path == null) return undefined;
 
       // add Route
       const path = route.format(generatorResult.path);
+      // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+      // @ts-ignore
       const { data, layout } = generatorResult;
 
       if (!layout) {
@@ -536,8 +540,8 @@ class Hexo extends EventEmitter {
         return path;
       }
 
-      return this.execFilter('template_locals', new Locals(path, data), { context: this })
-        .then(locals => { route.set(path, createLoadThemeRoute(generatorResult, locals, this)); })
+      return this.execFilter('template_locals', new Locals(path, data as unknown as NormalPageGenerator | NormalPostGenerator), { context: this })
+        .then(locals => { route.set(path, createLoadThemeRoute(generatorResult as NormalPageGenerator | NormalPostGenerator, locals, this)); })
         .thenReturn(path);
     }).then(newRouteList => {
       // Remove old routes
diff --git a/lib/plugins/filter/template_locals/i18n.ts b/lib/plugins/filter/template_locals/i18n.ts
index 9c5759c01b..87c505280b 100644
--- a/lib/plugins/filter/template_locals/i18n.ts
+++ b/lib/plugins/filter/template_locals/i18n.ts
@@ -1,18 +1,8 @@
 import { Pattern } from 'hexo-util';
 import type Hexo from '../../../hexo';
+import type { LocalsType } from '../../../types';
 
-interface Locals {
-  path: string;
-  page: {
-    lang: string;
-    language: string;
-    canonical_path: string;
-  };
-  __: (key: string) => string;
-  _p: (key: string, options?: any) => string;
-}
-
-function i18nLocalsFilter(this: Hexo, locals: Locals): void {
+function i18nLocalsFilter(this: Hexo, locals: LocalsType): void {
   const { i18n } = this.theme;
   const { config } = this;
   const i18nDir = config.i18n_dir;
diff --git a/lib/plugins/generator/asset.ts b/lib/plugins/generator/asset.ts
index 074f497620..336c4e2612 100644
--- a/lib/plugins/generator/asset.ts
+++ b/lib/plugins/generator/asset.ts
@@ -5,6 +5,7 @@ import { extname } from 'path';
 import { magenta } from 'picocolors';
 import type warehouse from 'warehouse';
 import type Hexo from '../../hexo';
+import type { AssetGenerator } from '../../types';
 
 interface Data {
   modified: boolean;
@@ -36,7 +37,7 @@ const process = (name: string, ctx: Hexo) => {
       data.data = () => ctx.render.render({
         path: source,
         toString: true
-      }).catch(err => {
+      }).catch((err: Error) => {
         ctx.log.error({err}, 'Asset render failed: %s', magenta(path));
       });
     } else {
@@ -47,7 +48,7 @@ const process = (name: string, ctx: Hexo) => {
   });
 };
 
-function assetGenerator(this: Hexo): Promise<any[]> {
+function assetGenerator(this: Hexo): Promise<AssetGenerator[]> {
   return Promise.all([
     process('Asset', this),
     process('PostAsset', this)
diff --git a/lib/plugins/generator/page.ts b/lib/plugins/generator/page.ts
index 8dbbcd817c..da2cf08c8b 100644
--- a/lib/plugins/generator/page.ts
+++ b/lib/plugins/generator/page.ts
@@ -1,5 +1,7 @@
-function pageGenerator(locals) {
-  return locals.pages.map(page => {
+import type { PageGenerator, PageSchema, SiteLocals } from '../../types';
+
+function pageGenerator(locals: SiteLocals): PageGenerator[] {
+  return locals.pages.map((page: PageSchema) => {
     const { path, layout } = page;
 
     if (!layout || layout === 'false' || layout === 'off') {
diff --git a/lib/plugins/generator/post.ts b/lib/plugins/generator/post.ts
index 4deec563dd..d97030b04f 100644
--- a/lib/plugins/generator/post.ts
+++ b/lib/plugins/generator/post.ts
@@ -1,8 +1,10 @@
-function postGenerator(locals) {
+import type { PostGenerator, PostSchema, SiteLocals } from '../../types';
+
+function postGenerator(locals: SiteLocals): PostGenerator[] {
   const posts = locals.posts.sort('-date').toArray();
   const { length } = posts;
 
-  return posts.map((post, i) => {
+  return posts.map((post: PostSchema, i: number) => {
     const { path, layout } = post;
 
     if (!layout || layout === 'false') {
diff --git a/lib/plugins/helper/date.ts b/lib/plugins/helper/date.ts
index 8d45b27147..063a437cb4 100644
--- a/lib/plugins/helper/date.ts
+++ b/lib/plugins/helper/date.ts
@@ -1,7 +1,7 @@
 import moment from 'moment-timezone';
 const { isMoment } = moment;
 import moize from 'moize';
-import type Hexo from '../../hexo';
+import type { LocalsType } from '../../types';
 
 const isDate = (value: moment.MomentInput | moment.Moment): boolean =>
   typeof value === 'object' && value instanceof Date && !isNaN(value.getTime());
@@ -61,7 +61,7 @@ function timeTagHelper(date: string | number | Date | moment.Moment, format: str
   return `<time datetime="${toISOString(date)}">${this.date(date, format, getLanguage(this), config.timezone)}</time>`;
 }
 
-function getLanguage(ctx) {
+function getLanguage(ctx: LocalsType) {
   return ctx.page.lang || ctx.page.language || ctx.config.language;
 }
 
diff --git a/lib/plugins/helper/is.ts b/lib/plugins/helper/is.ts
index 1f843cf3ff..ef9ec0fc46 100644
--- a/lib/plugins/helper/is.ts
+++ b/lib/plugins/helper/is.ts
@@ -1,4 +1,4 @@
-function isCurrentHelper(path = '/', strict) {
+function isCurrentHelper(path = '/', strict: boolean) {
   const currentPath = this.path.replace(/^[^/].*/, '/$&');
 
   if (strict) {
diff --git a/lib/plugins/injector/index.ts b/lib/plugins/injector/index.ts
index 6736417bc8..4c640279c1 100644
--- a/lib/plugins/injector/index.ts
+++ b/lib/plugins/injector/index.ts
@@ -1,6 +1,6 @@
 import type Hexo from '../../hexo';
 
 export = (ctx: Hexo) => {
-  // eslint-disable-next-line no-unused-vars
+  // eslint-disable-next-line @typescript-eslint/no-unused-vars
   const { injector } = ctx.extend;
 };
diff --git a/lib/theme/view.ts b/lib/theme/view.ts
index 9600d8be83..e96d2f0538 100644
--- a/lib/theme/view.ts
+++ b/lib/theme/view.ts
@@ -25,7 +25,7 @@ class Options {
 
 class View {
   public path: string;
-  public source: any;
+  public source: string;
   public _theme: Theme;
   public data: any;
   public _compiled: any;
@@ -89,6 +89,7 @@ class View {
   }
 
   _buildLocals(locals: Options) {
+    // eslint-disable-next-line @typescript-eslint/no-unused-vars
     const { layout, _content, ...data } = this.data;
     return assignIn({}, locals, data, {
       filename: this.source
diff --git a/lib/types.ts b/lib/types.ts
index 509686011c..6959a456cc 100644
--- a/lib/types.ts
+++ b/lib/types.ts
@@ -1,4 +1,5 @@
 import moment from 'moment';
+import type default_config from './hexo/default_config';
 
 export type NodeJSLikeCallback<R, E = any> = (err: E, result?: R) => void
 
@@ -14,6 +15,7 @@ export interface RenderData {
   more?: string;
 }
 
+// Schema
 export interface PostSchema {
   id?: string;
   _id?: string;
@@ -39,4 +41,89 @@ export interface PostSchema {
   categories?: any;
   tags?: any;
   __permalink?: string;
+  __post?: boolean;
+  canonical_path?: string;
+  lang?: string;
+  language?: string;
+  prev?: PostSchema;
+  next?: PostSchema;
+}
+
+export interface PageSchema {
+  _id?: string;
+  title?: string;
+  date?: moment.Moment,
+  updated?: moment.Moment,
+  comments?: boolean;
+  layout?: string;
+  _content?: string;
+  source?: string;
+  path?: string;
+  raw?: string;
+  content?: string;
+  excerpt?: string;
+  more?: string;
+  author?: string;
+  full_source?: string;
+  permalink?: string;
+  tags?: any;
+  canonical_path?: string;
+  lang?: string;
+  language?: string;
+  __page?: boolean;
+}
+
+export interface LocalsType {
+  page: PostSchema | PageSchema;
+  path: string;
+  url: string;
+  config: typeof default_config;
+  theme: object;
+  layout: string;
+  env: any;
+  view_dir: string;
+  site: object;
+  cache?: boolean;
+  __?: (key: string) => string;
+  _p?: (key: string, options?: any) => string;
+}
+
+// Generator return types
+export interface AssetGenerator {
+  path: string;
+  data: {
+    modified: boolean;
+    data?: () => any;
+  }
+}
+
+export type SimplePostGenerator = {
+  path: string;
+  data: string;
+}
+export type NormalPostGenerator = {
+  path: string;
+  layout: string[];
+  data: PostSchema;
+}
+export type PostGenerator = SimplePostGenerator | NormalPostGenerator;
+
+
+export type SimplePageGenerator = {
+  path: string;
+  data: string;
+}
+export type NormalPageGenerator = {
+  path: string;
+  layout: string[];
+  data: PageSchema;
+}
+export type PageGenerator = SimplePageGenerator | NormalPageGenerator;
+
+export interface SiteLocals {
+  posts: any; // _Query
+  pages: any; // _Query
+  categories: any; // _Model
+  tags: any; // _Model
+  data: object;
 }