diff --git a/.eslintrc.yml b/.eslintrc.yml
index f2ae14ba54..68fa76be51 100644
--- a/.eslintrc.yml
+++ b/.eslintrc.yml
@@ -137,7 +137,6 @@ rules:
   no-inner-declarations: off
 
   no-useless-constructor: off
-  '@typescript-eslint/no-useless-constructor': warn
 
   node/no-callback-literal: off
 
@@ -159,5 +158,3 @@ rules:
       asyncArrow: always
       named: never
   '@typescript-eslint/type-annotation-spacing': error
-
-  '@typescript-eslint/no-useless-constructor': off
diff --git a/packages/cli/src/worker/index.ts b/packages/cli/src/worker/index.ts
index d5615f1525..bc29be092b 100644
--- a/packages/cli/src/worker/index.ts
+++ b/packages/cli/src/worker/index.ts
@@ -9,17 +9,17 @@ export * from './utils'
 export { Loader, Watcher }
 
 declare module 'koishi' {
-  interface EventMap {
+  interface Events {
     'exit'(signal: NodeJS.Signals): Promise<void>
     'config'(): void
   }
 
-  interface App {
+  interface Context {
     prologue: string[]
     watcher: Watcher
   }
 
-  namespace App {
+  namespace Context {
     interface Config extends daemon.Config {
       plugins?: Dict
       timezoneOffset?: number
diff --git a/packages/cli/src/worker/loader.ts b/packages/cli/src/worker/loader.ts
index 123e00e8cf..d956e02613 100644
--- a/packages/cli/src/worker/loader.ts
+++ b/packages/cli/src/worker/loader.ts
@@ -1,27 +1,28 @@
 import { resolve } from 'path'
-import { App, Context, Dict, interpolate, Logger, Plugin, Registry, valueMap } from 'koishi'
+import { Context, Dict, interpolate, Logger, Plugin, valueMap } from 'koishi'
+import { resolveConfig } from 'cordis'
 import { patch, stripModifier } from './utils'
 import ConfigLoader from '@koishijs/loader'
 import * as dotenv from 'dotenv'
 import ns from 'ns-require'
 
 declare module 'koishi' {
-  namespace Context {
-    interface Services {
-      loader: Loader
-      delimiter: symbol
-    }
+  interface Context {
+    loader: Loader
+    delimiter: symbol
   }
+}
 
+declare module 'cordis' {
   interface Runtime {
     [Loader.kWarning]?: boolean
   }
 
   // Theoretically, these properties will only appear on `Fork`.
   // We define them directly on `State` for typing convenience.
-  interface State {
+  interface State<C> {
     [Loader.update]?: boolean
-    [Loader.kRecord]?: Dict<Fork>
+    [Loader.kRecord]?: Dict<Fork<C>>
     alias?: string
   }
 }
@@ -46,14 +47,14 @@ const group: Plugin.Object = {
   },
 }
 
-export default class Loader extends ConfigLoader<App.Config> {
+export default class Loader extends ConfigLoader<Context.Config> {
   static readonly unique = Symbol.for('koishi.loader.unique')
   static readonly update = Symbol.for('koishi.loader.update')
   static readonly kRecord = Symbol.for('koishi.loader.record')
   static readonly kWarning = Symbol.for('koishi.loader.warning')
 
-  app: App
-  config: App.Config
+  app: Context
+  config: Context.Config
   entry: Context
   cache: Dict<string> = {}
   envfile: string
@@ -89,11 +90,11 @@ export default class Loader extends ConfigLoader<App.Config> {
     // load original config file
     const config = super.readConfig()
 
-    let resolved = new App.Config(config)
+    let resolved = new Context.Config(config)
     if (this.writable) {
       // schemastery may change original config
       // so we need to validate config twice
-      resolved = new App.Config(this.interpolate(config))
+      resolved = new Context.Config(this.interpolate(config))
     }
 
     return resolved
@@ -123,7 +124,7 @@ export default class Loader extends ConfigLoader<App.Config> {
       this.app.lifecycle.flush().then(() => this.check(name))
     }
 
-    Registry.validate(plugin, config)
+    resolveConfig(plugin, config)
     return parent.plugin(plugin, this.interpolate(config))
   }
 
@@ -165,11 +166,11 @@ export default class Loader extends ConfigLoader<App.Config> {
   }
 
   createApp() {
-    const app = this.app = new App(this.config)
+    const app = this.app = new Context(this.config)
     app.loader = this
     app.baseDir = this.dirname
     app.state[Loader.kRecord] = Object.create(null)
-    this.entry = this.reloadPlugin(app, 'group:entry', this.config.plugins).context
+    this.entry = this.reloadPlugin(app, 'group:entry', this.config.plugins).ctx
 
     app.on('internal/update', (fork, value) => {
       // prevent hot reload when config file is being written
diff --git a/packages/cli/src/worker/watcher.ts b/packages/cli/src/worker/watcher.ts
index c192babee7..1eb52f151e 100644
--- a/packages/cli/src/worker/watcher.ts
+++ b/packages/cli/src/worker/watcher.ts
@@ -1,4 +1,4 @@
-import { App, coerce, Context, Dict, Logger, makeArray, Runtime, Schema } from 'koishi'
+import { coerce, Context, Dict, Logger, makeArray, Runtime, Schema } from 'koishi'
 import { FSWatcher, watch, WatchOptions } from 'chokidar'
 import { relative, resolve } from 'path'
 import { debounce } from 'throttle-debounce'
@@ -149,7 +149,7 @@ class Watcher {
       } else if (!(key in neo)) {
         this.ctx.loader.unloadPlugin(ctx, key)
       } else if (key.startsWith('group:')) {
-        this.triggerGroupReload(key, neo[key] || {}, old[key] || {}, fork.context)
+        this.triggerGroupReload(key, neo[key] || {}, old[key] || {}, fork.ctx)
       } else if (!deepEqual(old[key], neo[key])) {
         this.ctx.loader.reloadPlugin(ctx, key, neo[key])
       }
@@ -225,7 +225,7 @@ class Watcher {
     for (const filename in require.cache) {
       const module = require.cache[filename]
       const plugin = ns.unwrapExports(module.exports)
-      const runtime = this.ctx.app.registry.get(plugin)
+      const runtime = this.ctx.registry.get(plugin)
       if (!runtime || this.declined.has(filename)) continue
       pending.set(filename, runtime)
       if (!plugin['sideEffect']) this.declined.add(filename)
@@ -343,7 +343,7 @@ namespace Watcher {
     ]).description('要忽略的文件或目录。'),
   }).description('热重载设置')
 
-  App.Config.list.push(Schema.object({
+  Context.Config.list.push(Schema.object({
     watch: Config,
   }))
 }
diff --git a/plugins/a11y/bind/src/index.ts b/plugins/a11y/bind/src/index.ts
index b110c79fe3..9f1e32b044 100644
--- a/plugins/a11y/bind/src/index.ts
+++ b/plugins/a11y/bind/src/index.ts
@@ -47,7 +47,7 @@ export function apply(ctx: Context, config: Config = {}) {
     const data = tokens[session.content]
     if (!data) return next()
     if (data[2] < 0) {
-      const sess = new Session(session.bot, session)
+      const sess = session.bot.session(session)
       sess.platform = data[0]
       sess.userId = data[1]
       const user = await sess.observeUser([session.platform as never])
diff --git a/plugins/a11y/callme/src/index.ts b/plugins/a11y/callme/src/index.ts
index 1de9e78bf2..9bb5a1aa5b 100644
--- a/plugins/a11y/callme/src/index.ts
+++ b/plugins/a11y/callme/src/index.ts
@@ -1,7 +1,7 @@
 import { Context, RuntimeError, Schema } from 'koishi'
 
 declare module 'koishi' {
-  interface EventMap {
+  interface Events {
     'common/callme'(name: string, session: Session): string | void
   }
 }
diff --git a/plugins/a11y/schedule/src/index.ts b/plugins/a11y/schedule/src/index.ts
index 0fc29189aa..76ff8b3377 100644
--- a/plugins/a11y/schedule/src/index.ts
+++ b/plugins/a11y/schedule/src/index.ts
@@ -121,7 +121,7 @@ export function apply(ctx: Context, { minInterval }: Config) {
 
     data.forEach((schedule) => {
       const { session, assignee } = schedule
-      const bot = ctx.bots.get(assignee)
+      const bot = ctx.bots[assignee]
       if (bot) {
         prepareSchedule(schedule, new Session(bot, session))
       } else {
diff --git a/plugins/a11y/schedule/tests/index.spec.ts b/plugins/a11y/schedule/tests/index.spec.ts
index 9100f7c5f0..c71d805c65 100644
--- a/plugins/a11y/schedule/tests/index.spec.ts
+++ b/plugins/a11y/schedule/tests/index.spec.ts
@@ -4,8 +4,10 @@ import * as schedule from '@koishijs/plugin-schedule'
 import memory from '@koishijs/plugin-database-memory'
 import mock from '@koishijs/plugin-mock'
 import * as jest from 'jest-mock'
-import { expect } from 'chai'
-import 'chai-shape'
+import { expect, use } from 'chai'
+import shape from 'chai-shape'
+
+use(shape)
 
 describe('@koishijs/plugin-switch', () => {
   const app = new App()
diff --git a/plugins/a11y/suggest/src/index.ts b/plugins/a11y/suggest/src/index.ts
index 3ba156c347..d2fe0f2383 100644
--- a/plugins/a11y/suggest/src/index.ts
+++ b/plugins/a11y/suggest/src/index.ts
@@ -1,6 +1,5 @@
 import { distance } from 'fastest-levenshtein'
-import { Awaitable } from 'cosmokit'
-import { Context, Next, Schema, Session } from 'koishi'
+import { Awaitable, Context, Next, Schema, Session } from 'koishi'
 
 declare module 'koishi' {
   interface Context {
diff --git a/plugins/common/echo/tests/index.spec.ts b/plugins/common/echo/tests/index.spec.ts
index 06fb355fd7..5e05f64bfa 100644
--- a/plugins/common/echo/tests/index.spec.ts
+++ b/plugins/common/echo/tests/index.spec.ts
@@ -2,8 +2,10 @@ import { App, Bot } from 'koishi'
 import * as echo from '@koishijs/plugin-echo'
 import mock from '@koishijs/plugin-mock'
 import * as jest from 'jest-mock'
-import { expect } from 'chai'
-import 'chai-shape'
+import { expect, use } from 'chai'
+import shape from 'chai-shape'
+
+use(shape)
 
 const app = new App()
 
diff --git a/plugins/common/feedback/src/index.ts b/plugins/common/feedback/src/index.ts
index 5b900e8b58..f4b6f9c567 100644
--- a/plugins/common/feedback/src/index.ts
+++ b/plugins/common/feedback/src/index.ts
@@ -51,6 +51,6 @@ export function apply(ctx: Context, { operators = [], replyTimeout = Time.day }:
     if (!parsed.content || !quote) return next()
     const data = feedbacks[quote.messageId]
     if (!data) return next()
-    await ctx.bots.get(data[0]).sendMessage(data[1], parsed.content, data[2])
+    await ctx.bots[data[0]].sendMessage(data[1], parsed.content, data[2])
   })
 }
diff --git a/plugins/common/forward/src/index.ts b/plugins/common/forward/src/index.ts
index 38b5937bde..538ca36020 100644
--- a/plugins/common/forward/src/index.ts
+++ b/plugins/common/forward/src/index.ts
@@ -55,7 +55,7 @@ export function apply(ctx: Context, { rules, interval }: Config) {
         rule.guildId = channel.guildId
       }
 
-      const bot = ctx.bots.get(`${platform}:${rule.selfId}`)
+      const bot = ctx.bots[`${platform}:${rule.selfId}`]
       const chain = segment.parse(parsed.content)
 
       // replace all mentions (koishijs/koishi#506)
diff --git a/plugins/common/repeater/src/index.ts b/plugins/common/repeater/src/index.ts
index dc9a62e5ce..2795f102df 100644
--- a/plugins/common/repeater/src/index.ts
+++ b/plugins/common/repeater/src/index.ts
@@ -66,7 +66,7 @@ export function apply(ctx: Context, config: Config = {}) {
     const { content, uid, userId } = session
 
     // never respond to messages from self
-    if (ctx.bots.get(uid)) return
+    if (ctx.bots[uid]) return
 
     const state = getState(session.cid)
     const check = (handle: StateCallback) => {