diff --git a/.eslintrc.json b/.eslintrc.json
index 6be9a4c7cc..d82fdaa6b1 100644
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -4,5 +4,8 @@
   "parserOptions": {
     "sourceType": "module",
     "ecmaVersion": 2020
+  },
+  "rules": {
+    "@typescript-eslint/no-explicit-any": 0
   }
 }
diff --git a/lib/box/file.ts b/lib/box/file.ts
index ce5da96658..82cfc257c0 100644
--- a/lib/box/file.ts
+++ b/lib/box/file.ts
@@ -5,6 +5,10 @@ class File {
   public path: any;
   public params: any;
   public type: any;
+  static TYPE_CREATE: 'create';
+  static TYPE_UPDATE: 'update';
+  static TYPE_SKIP: 'skip';
+  static TYPE_DELETE: 'delete';
 
   constructor({ source, path, params, type }) {
     this.source = source;
diff --git a/lib/box/index.ts b/lib/box/index.ts
index 40dc07b85f..9c65efef72 100644
--- a/lib/box/index.ts
+++ b/lib/box/index.ts
@@ -1,5 +1,5 @@
 import {join, sep} from 'path';
-import Promise from 'bluebird';
+import BlueBirdPromise from 'bluebird';
 import File from './file';
 import {Pattern, createSha1Hash} from 'hexo-util';
 import {createReadStream, readdir, stat, watch} from 'hexo-fs';
@@ -9,21 +9,27 @@ import {isMatch, makeRe} from 'micromatch';
 
 const defaultPattern = new Pattern(() => ({}));
 
+interface Processor {
+  pattern: Pattern;
+  process: (file: File) => void;
+}
+
 class Box extends EventEmitter {
   public options: any;
   public context: any;
   public base: any;
-  public processors: any;
+  public processors: Processor[];
   public _processingFiles: any;
   public watcher: any;
   public Cache: any;
+  // TODO: replace runtime class _File
   public File: any;
   public ignore: any;
   public source: any;
   public emit: any;
   public ctx: any;
 
-  constructor(ctx, base, options) {
+  constructor(ctx, base, options?: object) {
     super();
 
     this.options = Object.assign({
@@ -51,10 +57,13 @@ class Box extends EventEmitter {
     this.ignore = targets;
     this.options.ignored = targets.map(s => toRegExp(ctx, s)).filter(x => x);
   }
+
   _createFileClass() {
     const ctx = this.context;
 
     class _File extends File {
+      public box: Box;
+
       render(options) {
         return ctx.render.render({
           path: this.source
@@ -132,7 +141,7 @@ class Box extends EventEmitter {
 
   _processFile(type, path) {
     if (this._processingFiles[path]) {
-      return Promise.resolve();
+      return BlueBirdPromise.resolve();
     }
 
     this._processingFiles[path] = true;
@@ -144,7 +153,7 @@ class Box extends EventEmitter {
       path
     });
 
-    return Promise.reduce(this.processors, (count, processor) => {
+    return BlueBirdPromise.reduce(this.processors, (count, processor) => {
       const params = processor.pattern.match(path);
       if (!params) return count;
 
@@ -155,7 +164,7 @@ class Box extends EventEmitter {
         type
       });
 
-      return Reflect.apply(Promise.method(processor.process), ctx, [file])
+      return Reflect.apply(BlueBirdPromise.method(processor.process), ctx, [file])
         .thenReturn(count + 1);
     }, 0).then(count => {
       if (count) {
@@ -175,7 +184,7 @@ class Box extends EventEmitter {
 
   watch(callback) {
     if (this.isWatching()) {
-      return Promise.reject(new Error('Watcher has already started.')).asCallback(callback);
+      return BlueBirdPromise.reject(new Error('Watcher has already started.')).asCallback(callback);
     }
 
     const { base } = this;
@@ -229,7 +238,7 @@ function getHash(path) {
   const src = createReadStream(path);
   const hasher = createSha1Hash();
 
-  const finishedPromise = new Promise((resolve, reject) => {
+  const finishedPromise = new BlueBirdPromise((resolve, reject) => {
     src.once('error', reject);
     src.once('end', resolve);
   });
@@ -258,9 +267,9 @@ function isIgnoreMatch(path, ignore) {
 }
 
 function readDirWalker(ctx, base, results, ignore, prefix) {
-  if (isIgnoreMatch(base, ignore)) return Promise.resolve();
+  if (isIgnoreMatch(base, ignore)) return BlueBirdPromise.resolve();
 
-  return Promise.map(readdir(base).catch(err => {
+  return BlueBirdPromise.map(readdir(base).catch(err => {
     ctx.log.error({ err }, 'Failed to read directory: %s', base);
     if (err && err.code === 'ENOENT') return [];
     throw err;
diff --git a/lib/hexo/index.ts b/lib/hexo/index.ts
index e176294e14..c6c98b1946 100644
--- a/lib/hexo/index.ts
+++ b/lib/hexo/index.ts
@@ -7,7 +7,7 @@ import {EventEmitter} from 'events';
 import {readFile} from 'hexo-fs';
 import Module from 'module';
 import {runInThisContext} from 'vm';
-import {version} from '../../package.json';
+const {version} = require('../../package.json');
 import logger from 'hexo-log';
 
 import {
@@ -105,6 +105,15 @@ function debounce(func, wait) {
   };
 }
 
+interface Args {
+  debug?: any;
+  safe?: any;
+  silent?: any;
+  _?: any[];
+  output?: any;
+  config?: any;
+}
+
 class Hexo extends EventEmitter {
   public base_dir: any;
   public public_dir: any;
@@ -143,7 +152,7 @@ class Hexo extends EventEmitter {
   public alias: any;
   public data: any;
 
-  constructor(base = process.cwd(), args = {}) {
+  constructor(base = process.cwd(), args: Args = {}) {
     super();
 
     this.base_dir = base + sep;
diff --git a/lib/hexo/post.ts b/lib/hexo/post.ts
index 967da8b349..1215b5aefa 100644
--- a/lib/hexo/post.ts
+++ b/lib/hexo/post.ts
@@ -218,6 +218,18 @@ const createAssetFolder = (path, assetFolder) => {
   });
 };
 
+interface Result {
+  path?: string;
+  content?: string;
+}
+
+interface Data {
+  engine?: string;
+  content?: string;
+  disableNunjucks?: boolean;
+  markdown?: object;
+}
+
 class Post {
   public context: any;
   public config: any;
@@ -329,7 +341,7 @@ class Post {
     data.slug = slug;
     const regex = new RegExp(`^${escapeRegExp(slug)}(?:[^\\/\\\\]+)`);
     let src = '';
-    const result = {};
+    const result: Result = {};
 
     data.layout = (data.layout || config.default_layout).toLowerCase();
 
@@ -367,7 +379,7 @@ class Post {
     }).thenReturn(result).asCallback(callback);
   }
 
-  render(source, data = {}, callback) {
+  render(source, data: Data = {}, callback) {
     const ctx = this.context;
     const { config } = ctx;
     const { tag } = ctx.extend;
diff --git a/lib/hexo/router.ts b/lib/hexo/router.ts
index d593560800..793e90a462 100644
--- a/lib/hexo/router.ts
+++ b/lib/hexo/router.ts
@@ -3,14 +3,19 @@ import Promise from 'bluebird';
 import Stream from 'stream';
 const { Readable } = Stream;
 
+interface Data {
+  data: any;
+  modified: boolean;
+}
+
 class RouteStream extends Readable {
   public _data: any;
-  public _ended: any;
+  public _ended: boolean;
   public modified: any;
   public push: any;
   public emit: any;
 
-  constructor(data) {
+  constructor(data: Data) {
     super({ objectMode: true });
 
     this._data = data.data;
@@ -75,7 +80,7 @@ class RouteStream extends Readable {
   }
 }
 
-const _format = path => {
+const _format = (path: string) => {
   path = path || '';
   if (typeof path !== 'string') throw new TypeError('path must be a string!');
 
@@ -93,7 +98,9 @@ const _format = path => {
 };
 
 class Router extends EventEmitter {
-  public routes: any;
+  public routes: {
+    [key: string]: Data | null;
+  };
   public emit: any;
 
   constructor() {
@@ -107,11 +114,11 @@ class Router extends EventEmitter {
     return Object.keys(routes).filter(key => routes[key]);
   }
 
-  format(path) {
+  format(path: string) {
     return _format(path);
   }
 
-  get(path) {
+  get(path: string) {
     if (typeof path !== 'string') throw new TypeError('path must be a string!');
 
     const data = this.routes[this.format(path)];
@@ -131,7 +138,7 @@ class Router extends EventEmitter {
     if (typeof path !== 'string') throw new TypeError('path must be a string!');
     if (data == null) throw new TypeError('data is required!');
 
-    let obj;
+    let obj: Data;
 
     if (typeof data === 'object' && data.data != null) {
       obj = data;
diff --git a/lib/theme/view.ts b/lib/theme/view.ts
index 96ab6ac209..422647ea21 100644
--- a/lib/theme/view.ts
+++ b/lib/theme/view.ts
@@ -16,6 +16,10 @@ const assignIn = (target, ...sources) => {
   return target;
 };
 
+class Options {
+  layout?: any;
+}
+
 class View {
   public path: any;
   public source: any;
@@ -36,13 +40,13 @@ class View {
     this._precompile();
   }
 
-  render(options = {}, callback) {
+  render(options: Options | Function = {}, callback) {
     if (!callback && typeof options === 'function') {
       callback = options;
       options = {};
     }
     const { data } = this;
-    const { layout = options.layout } = data;
+    const { layout = (options as Options).layout } = data;
     const locals = this._buildLocals(options);
 
     return this._compiled(this._bindHelpers(locals)).then(result => {
@@ -61,7 +65,7 @@ class View {
     }).asCallback(callback);
   }
 
-  renderSync(options = {}) {
+  renderSync(options: Options = {}) {
     const { data } = this;
     const { layout = options.layout } = data;
     const locals = this._buildLocals(options);