diff --git a/packages/core/src/database.ts b/packages/core/src/database.ts
index 97b16123..ba8bf6d9 100644
--- a/packages/core/src/database.ts
+++ b/packages/core/src/database.ts
@@ -48,12 +48,25 @@ export namespace Join2 {
 
 const kTransaction = Symbol('transaction')
 
-export class Database<S = any, N = any, C extends Context = Context> extends Service<undefined, C> {
+export namespace Database {
+  export interface Tables {}
+
+  export interface Types {}
+}
+
+export class Database<
+  C extends Context = Context,
+  S extends C[typeof Database.Tables] = C[typeof Database.Tables],
+  N extends C[typeof Database.Types] = C[typeof Database.Types],
+> extends Service<undefined, C> {
   static [Service.provide] = 'model'
   static [Service.immediate] = true
+  static readonly Tables = Symbol('minato.tables')
+  static readonly Types = Symbol('minato.types')
 
-  public tables: { [K in Keys<S>]: Model<S[K]> } = Object.create(null)
-  public drivers: Record<keyof any, Driver> = Object.create(null)
+  // { [K in Keys<S>]: Model<S[K]> }
+  public tables: any = Object.create(null)
+  public drivers: Record<keyof any, any> = Object.create(null)
   public types: Dict<Field.Transform> = Object.create(null)
   public migrating = false
   private prepareTasks: Dict<Promise<void>> = Object.create(null)
@@ -79,7 +92,7 @@ export class Database<S = any, N = any, C extends Context = Context> extends Ser
     }
   }
 
-  private getDriver(table: any) {
+  private getDriver(table: any): Driver<any, C> {
     // const model: Model = this.tables[name]
     // if (model.driver) return this.drivers[model.driver]
     const driver = Object.values(this.drivers)[0]
@@ -189,8 +202,13 @@ export class Database<S = any, N = any, C extends Context = Context> extends Ser
     return type
   }
 
-  define<K extends Exclude<Keys<N>, Field.Type | 'object' | 'array'>>(name: K, field: Field.Definition<N[K], N> | Field.Transform<N[K], any, N>): K
-  define<S>(field: Field.Definition<S, N> | Field.Transform<S, any, N>): Field.NewType<S>
+  // FIXME
+  // define<K extends Exclude<Keys<N>, Field.Type | 'object' | 'array'>>(
+  //   name: K,
+  //   field: Field.Definition<N[K], N> | Field.Transform<N[K], any, N>,
+  // ): K
+
+  // define<T>(field: Field.Definition<T, N> | Field.Transform<T, any, N>): Field.NewType<T>
   define(name: any, field?: any) {
     if (typeof name === 'object') {
       field = name
@@ -212,7 +230,11 @@ export class Database<S = any, N = any, C extends Context = Context> extends Ser
     return name as any
   }
 
-  migrate<K extends Keys<S>>(name: K, fields: Field.Extension<S[K], N>, callback: Model.Migration) {
+  migrate<K extends Keys<S>>(
+    name: K,
+    fields: Field.Extension<S[K], N>,
+    callback: Model.Migration<this>,
+  ) {
     this.extend(name, fields, { callback })
   }
 
@@ -222,8 +244,18 @@ export class Database<S = any, N = any, C extends Context = Context> extends Ser
     return new Selection(this.getDriver(table), table, query)
   }
 
-  join<const U extends Join1.Input<S>>(tables: U, callback?: Join1.Predicate<S, U>, optional?: boolean[]): Selection<Join1.Output<S, U>>
-  join<const U extends Join2.Input<S>>(tables: U, callback?: Join2.Predicate<S, U>, optional?: Dict<boolean, Keys<U>>): Selection<Join2.Output<S, U>>
+  join<const U extends Join1.Input<S>>(
+    tables: U,
+    callback?: Join1.Predicate<S, U>,
+    optional?: boolean[],
+  ): Selection<Join1.Output<S, U>>
+
+  join<const U extends Join2.Input<S>>(
+    tables: U,
+    callback?: Join2.Predicate<S, U>,
+    optional?: Dict<boolean, Keys<U>>,
+  ): Selection<Join2.Output<S, U>>
+
   join(tables: any, query?: any, optional?: any) {
     if (Array.isArray(tables)) {
       const sel = new Selection(this.getDriver(tables[0]), Object.fromEntries(tables.map((name) => [name, this.select(name)])))
@@ -233,7 +265,9 @@ export class Database<S = any, N = any, C extends Context = Context> extends Ser
       sel.args[0].optional = Object.fromEntries(tables.map((name, index) => [name, optional?.[index]]))
       return this.select(sel)
     } else {
-      const sel = new Selection(this.getDriver(Object.values(tables)[0]), valueMap(tables, (t: TableLike<S>) => typeof t === 'string' ? this.select(t) : t))
+      const sel = new Selection(this.getDriver(Object.values(tables)[0]), valueMap(tables, (t: TableLike<S>) => {
+        return typeof t === 'string' ? this.select(t) : t
+      }))
       if (typeof query === 'function') {
         sel.args[0].having = Eval.and(query(sel.row))
       }
@@ -242,7 +276,11 @@ export class Database<S = any, N = any, C extends Context = Context> extends Ser
     }
   }
 
-  async get<T extends Keys<S>, K extends Keys<S[T]>>(table: T, query: Query<S[T]>, cursor?: Driver.Cursor<K>): Promise<Pick<S[T], K>[]> {
+  async get<T extends Keys<S>, K extends Keys<S[T]>>(
+    table: T,
+    query: Query<S[T]>,
+    cursor?: Driver.Cursor<K>,
+  ): Promise<Pick<S[T], K>[]> {
     return this.select(table, query).execute(cursor)
   }
 
@@ -250,7 +288,11 @@ export class Database<S = any, N = any, C extends Context = Context> extends Ser
     return this.select(table, query).execute(typeof expr === 'function' ? expr : () => expr)
   }
 
-  async set<T extends Keys<S>>(table: T, query: Query<S[T]>, update: Row.Computed<S[T], Update<S[T]>>): Promise<Driver.WriteResult> {
+  async set<T extends Keys<S>>(
+    table: T,
+    query: Query<S[T]>,
+    update: Row.Computed<S[T], Update<S[T]>>,
+  ): Promise<Driver.WriteResult> {
     const sel = this.select(table, query)
     if (typeof update === 'function') update = update(sel.row)
     const primary = makeArray(sel.model.primary)
diff --git a/packages/core/src/driver.ts b/packages/core/src/driver.ts
index b9f0d4db..508e0cdb 100644
--- a/packages/core/src/driver.ts
+++ b/packages/core/src/driver.ts
@@ -44,7 +44,7 @@ export namespace Driver {
   export type Constructor<T> = new (ctx: Context, config: T) => Driver<T>
 }
 
-export abstract class Driver<T = any> {
+export abstract class Driver<T = any, C extends Context = Context> {
   static inject = ['model']
 
   abstract start(): Promise<void>
@@ -61,11 +61,11 @@ export abstract class Driver<T = any> {
   abstract upsert(sel: Selection.Mutable, data: any[], keys: string[]): Promise<Driver.WriteResult>
   abstract withTransaction(callback: (driver: this) => Promise<void>): Promise<void>
 
-  public database: Database
+  public database: Database<C>
   public logger: Logger
   public types: Dict<Driver.Transformer> = Object.create(null)
 
-  constructor(public ctx: Context, public config: T) {
+  constructor(public ctx: C, public config: T) {
     this.database = ctx.model
     this.logger = ctx.logger(this.constructor.name)
 
diff --git a/packages/core/src/index.ts b/packages/core/src/index.ts
index 35d87689..51804c06 100644
--- a/packages/core/src/index.ts
+++ b/packages/core/src/index.ts
@@ -16,8 +16,10 @@ declare module 'cordis' {
   }
 
   interface Context {
-    database: Database
-    model: Database
+    [Database.Tables]: Database.Tables
+    [Database.Types]: Database.Types
+    database: Database<this>
+    model: Database<this>
   }
 }
 
diff --git a/packages/core/src/model.ts b/packages/core/src/model.ts
index b3aab7c3..cb731d5d 100644
--- a/packages/core/src/model.ts
+++ b/packages/core/src/model.ts
@@ -1,15 +1,16 @@
 import { Binary, clone, isNullable, makeArray, MaybeArray, valueMap } from 'cosmokit'
-import { Database } from './database.ts'
 import { Eval, isEvalExpr } from './eval.ts'
 import { Flatten, Keys, unravel } from './utils.ts'
 import { Type } from './type.ts'
 import { Driver } from './driver.ts'
+import { Selection } from './selection.ts'
 
 export const Primary = Symbol('Primary')
 export type Primary = (string | number) & { [Primary]: true }
 
 export interface Field<T = any> {
-  type: Type<T>
+  // FIXME Type<T>
+  type: Field.Type<T> | Type<T>
   deftype?: Field.Type<T>
   length?: number
   nullable?: boolean
@@ -75,8 +76,11 @@ export namespace Field {
     type: Type<T> | Field<T>['type']
   } & Omit<Field<T>, 'type'>
 
+  // FIXME
+  // eslint-disable-next-line @typescript-eslint/no-unused-vars
   type MapField<O = any, N = any> = {
-    [K in keyof O]?: Literal<O[K], N> | Definition<O[K], N> | Transform<O[K], any, N>
+    // [K in keyof O]?: Literal<O[K], N> | Definition<O[K], N> | Transform<O[K], any, N>
+    [K in keyof O]?: Field<O[K]> | Shorthand<Type<O[K]>> | Selection.Callback<O, O[K]>
   }
 
   export type Extension<O = any, N = any> = MapField<Flatten<O>, N>
@@ -134,7 +138,7 @@ export namespace Field {
 }
 
 export namespace Model {
-  export type Migration = (database: Database) => Promise<void>
+  export type Migration<D = any> = (database: D) => Promise<void>
 
   export interface Config<O = {}> {
     callback?: Migration
diff --git a/packages/core/src/selection.ts b/packages/core/src/selection.ts
index cab05eeb..54c121f7 100644
--- a/packages/core/src/selection.ts
+++ b/packages/core/src/selection.ts
@@ -160,7 +160,7 @@ export interface Selection extends Executable.Payload {
 export class Selection<S = any> extends Executable<S, S[]> {
   public tables: Dict<Model> = {}
 
-  constructor(driver: Driver, table: string | Selection | Dict<Selection.Immutable>, query?: Query) {
+  constructor(driver: Driver<any>, table: string | Selection | Dict<Selection.Immutable>, query?: Query) {
     super(driver, {
       type: 'get',
       ref: randomId(),
diff --git a/packages/core/src/type.ts b/packages/core/src/type.ts
index 9c71208e..439e474a 100644
--- a/packages/core/src/type.ts
+++ b/packages/core/src/type.ts
@@ -1,11 +1,12 @@
 import { Binary, defineProperty, isNullable, mapValues } from 'cosmokit'
 import { Field } from './model.ts'
 import { Eval, isEvalExpr } from './eval.ts'
-import { Keys } from './utils.ts'
+// import { Keys } from './utils.ts'
 
 export interface Type<T = any, N = any> {
   [Type.kType]?: true
-  type: Field.Type<T> | Keys<N, T> | Field.NewType<T>
+  // FIXME
+  type: Field.Type<T> // | Keys<N, T> | Field.NewType<T>
   inner?: T extends (infer I)[] ? Type<I, N> : Field.Type<T> extends 'json' ? { [key in keyof T]: Type<T[key], N> } : never
   array?: boolean
 }
@@ -49,9 +50,10 @@ export namespace Type {
     throw new TypeError(`invalid primitive: ${value}`)
   }
 
-  export function fromField<T, N>(field: Type | Field<T> | Field.Type<T> | Keys<N, T> | Field.NewType<T>): Type<T, N> {
+  // FIXME: Type | Field<T> | Field.Type<T> | Keys<N, T> | Field.NewType<T>
+  export function fromField<T, N>(field: any): Type<T, N> {
     if (isType(field)) return field
-    if (typeof field === 'string') return defineProperty({ type: field }, kType, true)
+    if (typeof field === 'string') return defineProperty({ type: field }, kType, true) as never
     else if (field.type) return field.type
     else if (field.expr?.[kType]) return field.expr[kType]
     throw new TypeError(`invalid field: ${field}`)
diff --git a/packages/sqlite/src/index.ts b/packages/sqlite/src/index.ts
index f6b67469..8fdad043 100644
--- a/packages/sqlite/src/index.ts
+++ b/packages/sqlite/src/index.ts
@@ -326,7 +326,7 @@ export class SQLiteDriver extends Driver<SQLiteDriver.Config> {
       return Object.keys(fields).find(field => field === key || key.startsWith(field + '.'))!
     }))]
     const primaryFields = makeArray(primary)
-    const data = await this.database.get(table, query)
+    const data = await this.database.get(table as never, query)
     for (const row of data) {
       this.#update(sel, primaryFields, updateFields, update, row)
     }
@@ -362,7 +362,7 @@ export class SQLiteDriver extends Driver<SQLiteDriver.Config> {
     const step = Math.floor(960 / keys.length)
     for (let i = 0; i < data.length; i += step) {
       const chunk = data.slice(i, i + step)
-      const results = await this.database.get(table, {
+      const results = await this.database.get(table as never, {
         $or: chunk.map(item => Object.fromEntries(keys.map(key => [key, item[key]]))),
       })
       for (const item of chunk) {