add-frontend-feature

name	add-frontend-feature
description	Step-by-step guide to add a new feature to the React frontend. Covers TypeScript types, API endpoints, query hooks, mutation hooks, components, routes, and dialogs. Use when creating new UI features connected to backend APIs.

Add Frontend Feature

Sequential guide for adding a new feature module to the React frontend. The items feature is the canonical reference.

Step 1: Types (types/your-entity.ts)

export interface YourEntity {
  id: string
  name: string
  description: string | null
  created_at: string
  updated_at: string
}

export interface YourEntityCreate {
  name: string
  description?: string
}

export interface YourEntityUpdate {
  name?: string
  description?: string
}

Step 2: API Endpoints (lib/api-endpoints.ts)

Add to the API constant:

export const API = {
  // ... existing endpoints ...
  YOUR_ENTITIES: {
    LIST: '/api/v1/your-entities',
    CREATE: '/api/v1/your-entities',
    DETAIL: (id: string) => `/api/v1/your-entities/${id}`,
    UPDATE: (id: string) => `/api/v1/your-entities/${id}`,
    DELETE: (id: string) => `/api/v1/your-entities/${id}`,
  },
} as const

Step 3: Query Keys (lib/query-keys.ts)

Add a key factory:

export const queryKeys = {
  // ... existing keys ...
  yourEntities: {
    all: ['your-entities'] as const,
    list: () => [...queryKeys.yourEntities.all, 'list'] as const,
    detail: (id: string) => [...queryKeys.yourEntities.all, 'detail', id] as const,
  },
}

Step 4: Zod Schema (lib/schemas/your-entity.ts)

import { z } from 'zod'

export const yourEntitySchema = z.object({
  name: z.string().min(1, 'Name is required').max(255),
  description: z.string().max(5000).optional(),
})

export type YourEntityFormData = z.infer<typeof yourEntitySchema>

Step 5: Query Hook (hooks/queries/useYourEntitiesQuery.ts)

import { queryOptions } from '@tanstack/react-query'
import { api } from '@/lib/api-client'
import { API } from '@/lib/api-endpoints'
import { queryKeys } from '@/lib/query-keys'
import type { YourEntity } from '@/types/your-entity'

export const yourEntitiesQueryOptions = () =>
  queryOptions({
    queryKey: queryKeys.yourEntities.list(),
    queryFn: () => api.get<YourEntity[]>(API.YOUR_ENTITIES.LIST),
    staleTime: 1000 * 60 * 5,
  })

export const yourEntityDetailQueryOptions = (id: string) =>
  queryOptions({
    queryKey: queryKeys.yourEntities.detail(id),
    queryFn: () => api.get<YourEntity>(API..(id)),
    :  *  * ,
  })

Step 6: Mutation Hooks (hooks/mutations/useYourEntityMutations.ts)

import { useMutation, useQueryClient } from '@tanstack/react-query'
import { api } from '@/lib/api-client'
import { API } from '@/lib/api-endpoints'
import { queryKeys } from '@/lib/query-keys'
import type { YourEntityCreate, YourEntityUpdate } from '@/types/your-entity'

export function useCreateYourEntity() {
  const queryClient = useQueryClient()
  return useMutation({
    mutationFn: (data: YourEntityCreate) =>
      api.post(API.YOUR_ENTITIES.CREATE, data),
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: queryKeys.yourEntities.all })
    },
  })
}

export function useUpdateYourEntity() {
  const queryClient = useQueryClient()
  return useMutation({
    : 
      api.(..(id), data),
    :  {
      queryClient.({ : queryKeys.. })
    },
  })
}

  () {
   queryClient = ()
   ({
    :  api.(..(id)),
    :  {
      queryClient.({ : queryKeys.. })
    },
  })
}

Step 7: Components

List Component (components/your-entities/YourEntitiesList.tsx)

import { useQuery } from '@tanstack/react-query'
import { yourEntitiesQueryOptions } from '@/hooks/queries/useYourEntitiesQuery'

export function YourEntitiesList() {
  const { data, isLoading, error } = useQuery(yourEntitiesQueryOptions())

  if (isLoading) return <div>Loading...</div>
  if (error) return <div>Error: {error.message}</div>

  return (
    <div>
      {data?.map((entity) => (
        <div key={entity.id}>{entity.name}</div>
      ))}
    </div>
  )
}

Form Dialog (components/your-entities/dialogs/YourEntityFormDialog.tsx)

import { useForm } from 'react-hook-form'
import { zodResolver } from '@hookform/resolvers/zod'
import { yourEntitySchema, type YourEntityFormData } from '@/lib/schemas/your-entity'
import { useCreateYourEntity } from '@/hooks/mutations/useYourEntityMutations'
import { toast } from 'sonner'

export function CreateYourEntityDialog() {
  const createMutation = useCreateYourEntity()
  const form = useForm<YourEntityFormData>({
    resolver: zodResolver(yourEntitySchema),
    defaultValues: { name: '', description: '' },
  })

  async function onSubmit(data: YourEntityFormData) {
    try {
      await createMutation.mutateAsync(data)
      toast.success('Created successfully')
    } catch (error) {
      toast.error('Failed to create')
    }
  }

  return (
    // Use shadcn/ui Dialog + Form components
    
  )
}

Step 8: Route (routes/your-entities.tsx)

import { createFileRoute } from '@tanstack/react-router'
import { YourEntitiesList } from '@/components/your-entities/YourEntitiesList'

export const Route = createFileRoute('/your-entities')({
  component: YourEntitiesPage,
})

function YourEntitiesPage() {
  return (
    <div className="container mx-auto py-6">
      <h1 className="text-2xl font-bold mb-6">Your Entities</h1>
      <YourEntitiesList />
    </div>
  )
}

After creating the route file, run bun run dev to auto-generate the route tree.

Step 9: Navigation

Add a link in components/common/Navigation.tsx:

<Link to="/your-entities">Your Entities</Link>

Folder Structure Result

src/
├── types/your-entity.ts
├── lib/
│   ├── api-endpoints.ts        (updated)
│   ├── query-keys.ts           (updated)
│   └── schemas/your-entity.ts
├── hooks/
│   ├── queries/useYourEntitiesQuery.ts
│   └── mutations/useYourEntityMutations.ts
├── components/
│   └── your-entities/
│       ├── YourEntitiesList.tsx
│       └── dialogs/
│           └── YourEntityFormDialog.tsx
└── routes/
    └── your-entities.tsx

Checklist

• Types defined in types/
• API endpoints added to api-endpoints.ts
• Query keys added to query-keys.ts
• Zod schema in lib/schemas/
• Query hook(s) in hooks/queries/
• Mutation hook(s) in hooks/mutations/
• List/detail components in components/{feature}/
• Form dialog with Zod + react-hook-form
• Route file in routes/
• Navigation link added
• Error handling with toast notifications
• Tests written