`ApiTypes<TApi>`

Extracts the inferred request and response types from a fully typed API client.


import type { ApiTypes } from '@routar/core'
 
type TodoApiTypes = ApiTypes<typeof todoApi>
 
type CreateRequest  = TodoApiTypes['create']['request']   // { body: { title: string } }
type CreateResponse = TodoApiTypes['create']['response']  // Todo
type ListResponse   = TodoApiTypes['getList']['response'] // Todo[]

Why use it

When you need to reference the input or output types of an API call — in form handlers, server actions, state types, or function signatures — ApiTypes derives them from the single source of truth instead of duplicating type definitions:


// ❌ duplicating the type manually
type CreateTodoInput = { body: { title: string } }
 
// ✅ derived from the API client
type CreateTodoInput = ApiTypes<typeof todoApi>['create']['request']

Type shape

The resulting type is an object keyed by endpoint name, each with request and response fields:


type TodoApiTypes = ApiTypes<typeof todoApi>
// {
//   getList:   { request: {};                          response: Todo[] }
//   getDetail: { request: { path: { id: number } };   response: Todo   }
//   create:    { request: { body: { title: string } }; response: Todo  }
// }

With nested routers

For nested routers, index through the client shape:


const api = createApi(executor, apiRouter)
type ApiT = ApiTypes<typeof api>
 
type UserDetailResponse = ApiT['users']['getDetail']['response']
type UserTodosResponse  = ApiT['users']['todos']['getList']['response']

Exporting types from an API module

The standard pattern is to export ApiTypes alongside the API client so consumers can reference the types without re-importing @routar/core:


// todo.api.ts
export const todoApi = createApi(executor, todoRouter)
export type TodoApiTypes = ApiTypes<typeof todoApi>
export type TodoItem = TodoApiTypes['getDetail']['response']