bsky-social-app/CLAUDE.md

CLAUDE.md - Bluesky Social App Development Guide

This document provides guidance for working effectively in the Bluesky Social app codebase.

Project Overview

Bluesky Social is a cross-platform social media application built with React Native and Expo. It runs on iOS, Android, and Web, connecting to the AT Protocol (atproto) decentralized social network.

Tech Stack:

• React Native 0.81 with Expo 54
• TypeScript
• React Navigation for routing
• TanStack Query (React Query) for data fetching
• Lingui for internationalization
• Custom design system called ALF (Application Layout Framework)

Essential Commands

# Development
yarn start              # Start Expo dev server
yarn web                # Start web version
yarn android            # Run on Android
yarn ios                # Run on iOS

# Testing & Quality
# IMPORTANT: Always use these yarn scripts, never call the underlying tools directly
yarn test               # Run Jest tests
yarn lint               # Run ESLint
yarn typecheck          # Run TypeScript type checking

# Internationalization
# DO NOT run these commands - extraction and compilation are handled by CI
yarn intl:extract       # Extract translation strings (nightly CI job)
yarn intl:compile       # Compile translations for runtime (nightly CI job)

# Build
yarn build-web          # Build web version
yarn prebuild           # Generate native projects

Project Structure

src/
├── alf/                    # Design system (ALF) - themes, atoms, tokens
├── components/             # Shared UI components (Button, Dialog, Menu, etc.)
├── screens/                # Full-page screen components (newer pattern)
├── view/
│   ├── screens/            # Full-page screens (legacy location)
│   ├── com/                # Reusable view components
│   └── shell/              # App shell (navigation bars, tabs)
├── state/
│   ├── queries/            # TanStack Query hooks
│   ├── preferences/        # User preferences (React Context)
│   ├── session/            # Authentication state
│   └── persisted/          # Persistent storage layer
├── lib/                    # Utilities, constants, helpers
├── locale/                 # i18n configuration and language files
└── Navigation.tsx          # Main navigation configuration

Styling System (ALF)

ALF is the custom design system. It uses Tailwind-inspired naming with underscores instead of hyphens.

Basic Usage

import {atoms as a, useTheme} from '#/alf'

function MyComponent() {
  const t = useTheme()

  return (
    <View style={[a.flex_row, a.gap_md, a.p_lg, t.atoms.bg]}>
      <Text style={[a.text_md, a.font_bold, t.atoms.text]}>
        Hello
      </Text>
    </View>
  )
}

Key Concepts

Static Atoms - Theme-independent styles imported from atoms:

import {atoms as a} from '#/alf'
// a.flex_row, a.p_md, a.gap_sm, a.rounded_md, a.text_lg, etc.

Theme Atoms - Theme-dependent colors from useTheme():

const t = useTheme()
// t.atoms.bg, t.atoms.text, t.atoms.border_contrast_low, etc.
// t.palette.primary_500, t.palette.negative_400, etc.

Platform Utilities - For platform-specific styles:

import {web, native, ios, android, platform} from '#/alf'

const styles = [
  a.p_md,
  web({cursor: 'pointer'}),
  native({paddingBottom: 20}),
  platform({ios: {...}, android: {...}, web: {...}}),
]

Breakpoints - Responsive design:

import {useBreakpoints} from '#/alf'

const {gtPhone, gtMobile, gtTablet} = useBreakpoints()
if (gtMobile) {
  // Tablet or desktop layout
}

Naming Conventions

• Spacing: 2xs, xs, sm, md, lg, xl, 2xl (t-shirt sizes)
• Text: text_xs, text_sm, text_md, text_lg, text_xl
• Gaps/Padding: gap_sm, p_md, px_lg, py_xl
• Flex: flex_row, flex_1, align_center, justify_between
• Borders: border, border_t, rounded_md, rounded_full

Component Patterns

Dialog Component

Dialogs use a bottom sheet on native and a modal on web. Use useDialogControl() hook to manage state.

import * as Dialog from '#/components/Dialog'

function MyFeature() {
  const control = Dialog.useDialogControl()

  return (
    <>
      <Button label="Open" onPress={control.open}>
        <ButtonText>Open Dialog</ButtonText>
      </Button>

      <Dialog.Outer control={control}>
        {/* Typically the inner part is in its own component */}
        <Dialog.Handle />  {/* Native-only drag handle */}
        <Dialog.ScrollableInner label={_(msg`My Dialog`)}>
          <Dialog.Header>
            <Dialog.HeaderText>Title</Dialog.HeaderText>
          </Dialog.Header>

          <Text>Dialog content here</Text>

          <Button label="Done" onPress={() => control.close()}>
            <ButtonText>Done</ButtonText>
          </Button>
          <Dialog.Close /> {/* Web-only X button in top left */}
        </Dialog.ScrollableInner>
      </Dialog.Outer>
    </>
  )
}

Menu Component

Menus render as a dropdown on web and a bottom sheet dialog on native.

import * as Menu from '#/components/Menu'

function MyMenu() {
  return (
    <Menu.Root>
      <Menu.Trigger label="Open menu">
        {({props}) => (
          <Button {...props} label="Menu">
            <ButtonIcon icon={DotsHorizontal} />
          </Button>
        )}
      </Menu.Trigger>

      <Menu.Outer>
        <Menu.Group>
          <Menu.Item label="Edit" onPress={handleEdit}>
            <Menu.ItemIcon icon={Pencil} />
            <Menu.ItemText>Edit</Menu.ItemText>
          </Menu.Item>
          <Menu.Item label="Delete" onPress={handleDelete}>
            <Menu.ItemIcon icon={Trash} />
            <Menu.ItemText>Delete</Menu.ItemText>
          </Menu.Item>
        </Menu.Group>
      </Menu.Outer>
    </Menu.Root>
  )
}

Button Component

import {Button, ButtonText, ButtonIcon} from '#/components/Button'

// Solid primary button (most common)
<Button label="Save" onPress={handleSave} color="primary" size="large">
  <ButtonText>Save</ButtonText>
</Button>

// With icon
<Button label="Share" onPress={handleShare} color="secondary" size="small">
  <ButtonIcon icon={Share} />
  <ButtonText>Share</ButtonText>
</Button>

// Icon-only button
<Button label="Close" onPress={handleClose} color="secondary" size="small" shape="round">
  <ButtonIcon icon={XIcon} />
</Button>

// Ghost variant (deprecated - use color prop)
<Button label="Cancel" variant="ghost" color="secondary" size="small">
  <ButtonText>Cancel</ButtonText>
</Button>

Button Props:

• color: 'primary' | 'secondary' | 'negative' | 'primary_subtle' | 'negative_subtle' | 'secondary_inverted'
• size: 'tiny' | 'small' | 'large'
• shape: 'default' (pill) | 'round' | 'square' | 'rectangular'
• variant: 'solid' | 'outline' | 'ghost' (deprecated, use color)

Typography

import {Text, H1, H2, P} from '#/components/Typography'

<H1 style={[a.text_xl, a.font_bold]}>Heading</H1>
<P>Paragraph text with default styling.</P>
<Text style={[a.text_sm, t.atoms.text_contrast_medium]}>Custom text</Text>

// For text with emoji, add the emoji prop
<Text emoji>Hello! 👋</Text>

TextField

import * as TextField from '#/components/forms/TextField'

<TextField.LabelText>Email</TextField.LabelText>
<TextField.Root>
  <TextField.Icon icon={AtSign} />
  <TextField.Input
    label="Email address"
    placeholder="you@example.com"
    defaultValue={email}
    onChangeText={setEmail}
    keyboardType="email-address"
    autoCapitalize="none"
  />
</TextField.Root>

Internationalization (i18n)

All user-facing strings must be wrapped for translation using Lingui.

import {msg, plural} from '@lingui/core/macro'
import {Trans} from '@lingui/react/macro'
import {useLingui} from '@lingui/react'

function MyComponent() {
  const {_} = useLingui()

  // Simple strings - use msg() with _() function
  const title = _(msg`Settings`)
  const errorMessage = _(msg`Something went wrong`)

  // Strings with variables
  const greeting = _(msg`Hello, ${name}!`)

  // Pluralization
  const countLabel = _(plural(count, {
    one: '# item',
    other: '# items',
  }))

  // JSX content - use Trans component
  return (
    <Text>
      <Trans>Welcome to <Text style={a.font_bold}>Bluesky</Text></Trans>
    </Text>
  )
}

Commands:

# DO NOT run these commands - extraction and compilation are handled by a nightly CI job
yarn intl:extract    # Extract new strings to locale files
yarn intl:compile    # Compile translations for runtime

State Management

TanStack Query (Data Fetching)

// src/state/queries/profile.ts
import {useQuery, useMutation, useQueryClient} from '@tanstack/react-query'

// Query key pattern
const RQKEY_ROOT = 'profile'
export const RQKEY = (did: string) => [RQKEY_ROOT, did]

// Query hook
export function useProfileQuery({did}: {did: string}) {
  const agent = useAgent()

  return useQuery({
    queryKey: RQKEY(did),
    queryFn: async () => {
      const res = await agent.getProfile({actor: did})
      return res.data
    },
    staleTime: STALE.MINUTES.FIVE,
    enabled: !!did,
  })
}

// Mutation hook
export function useUpdateProfile() {
  const queryClient = useQueryClient()

  return useMutation({
    mutationFn: async (data) => {
      // Update logic
    },
    onSuccess: (_, variables) => {
      queryClient.invalidateQueries({queryKey: RQKEY(variables.did)})
    },
    onError: (error) => {
      if (isNetworkError(error)) {
        // don't log, but inform user
      } else if (error instanceof AppBskyExampleProcedure.ExampleError) {
        // XRPC APIs often have typed errors, allows nicer handling
      } else {
        // Log unexpected errors to Sentry
        logger.error('Error updating profile', {safeMessage: error})
      }
    }
  })
}

Stale Time Constants (from src/state/queries/index.ts):

STALE.SECONDS.FIFTEEN  // 15 seconds
STALE.MINUTES.ONE      // 1 minute
STALE.MINUTES.FIVE     // 5 minutes
STALE.HOURS.ONE        // 1 hour
STALE.INFINITY         // Never stale

Paginated APIs: Many atproto APIs return paginated results with a cursor. Use useInfiniteQuery for these:

export function useDraftsQuery() {
  const agent = useAgent()

  return useInfiniteQuery({
    queryKey: ['drafts'],
    queryFn: async ({pageParam}) => {
      const res = await agent.app.bsky.draft.getDrafts({cursor: pageParam})
      return res.data
    },
    initialPageParam: undefined as string | undefined,
    getNextPageParam: page => page.cursor,
  })
}

To get all items from pages: data?.pages.flatMap(page => page.items) ?? []

Preferences (React Context)

// Simple boolean preference pattern
import {useAutoplayDisabled, useSetAutoplayDisabled} from '#/state/preferences'

function SettingsScreen() {
  const autoplayDisabled = useAutoplayDisabled()
  const setAutoplayDisabled = useSetAutoplayDisabled()

  return (
    <Toggle
      value={autoplayDisabled}
      onValueChange={setAutoplayDisabled}
    />
  )
}

Session State

import {useSession, useAgent} from '#/state/session'

function MyComponent() {
  const {hasSession, currentAccount} = useSession()
  const agent = useAgent()

  if (!hasSession) {
    return <LoginPrompt />
  }

  // Use agent for API calls
  const response = await agent.getProfile({actor: currentAccount.did})
}

Navigation

Navigation uses React Navigation with type-safe route parameters.

// Screen component
import {type NativeStackScreenProps} from '@react-navigation/native-stack'
import {type CommonNavigatorParams} from '#/lib/routes/types'

type Props = NativeStackScreenProps<CommonNavigatorParams, 'Profile'>

export function ProfileScreen({route, navigation}: Props) {
  const {name} = route.params  // Type-safe params

  return (
    <Layout.Screen>
      {/* Screen content */}
    </Layout.Screen>
  )
}

// Programmatic navigation
import {useNavigation} from '@react-navigation/native'

const navigation = useNavigation()
navigation.navigate('Profile', {name: 'alice.bsky.social'})

// Or use the navigate helper
import {navigate} from '#/Navigation'
navigate('Profile', {name: 'alice.bsky.social'})

Platform-Specific Code

Use file extensions for platform-specific implementations:

Component.tsx          # Shared/default
Component.web.tsx      # Web-only
Component.native.tsx   # iOS + Android
Component.ios.tsx      # iOS-only
Component.android.tsx  # Android-only

Example from Dialog:

• src/components/Dialog/index.tsx - Native (uses BottomSheet)
• src/components/Dialog/index.web.tsx - Web (uses modal with Radix primitives)

Important: The bundler automatically resolves platform-specific files. Just import normally:

// CORRECT - bundler picks storage.ts or storage.web.ts automatically
import * as storage from '#/state/drafts/storage'

// WRONG - don't use require() or conditional imports for platform files
const storage = IS_NATIVE
  ? require('#/state/drafts/storage')
  : require('#/state/drafts/storage.web')

Platform detection (for runtime logic, not imports):

import {IS_WEB, IS_NATIVE, IS_IOS, IS_ANDROID} from '#/env'

if (IS_NATIVE) {
  // Native-specific logic
}

Import Aliases

Always use the #/ alias for absolute imports:

// Good
import {useSession} from '#/state/session'
import {atoms as a, useTheme} from '#/alf'
import {Button} from '#/components/Button'

// Avoid
import {useSession} from '../../../state/session'

Footguns

Common pitfalls to avoid in this codebase:

Dialog Close Callback (Critical)

Always use control.close(() => ...) when performing actions after closing a dialog. The callback ensures the action runs after the dialog's close animation completes. Failing to do this causes race conditions with React state updates.

// WRONG - causes bugs with state updates, navigation, opening other dialogs
const onConfirm = () => {
  control.close()
  navigation.navigate('Home')  // May race with dialog animation
}

// WRONG - same problem
const onConfirm = () => {
  control.close()
  otherDialogControl.open()  // Will likely fail or cause visual glitches
}

// CORRECT - action runs after dialog fully closes
const onConfirm = () => {
  control.close(() => {
    navigation.navigate('Home')
  })
}

// CORRECT - opening another dialog after close
const onConfirm = () => {
  control.close(() => {
    otherDialogControl.open()
  })
}

// CORRECT - state updates after close
const onConfirm = () => {
  control.close(() => {
    setSomeState(newValue)
    onCallback?.()
  })
}

This applies to:

• Navigation (navigation.navigate(), navigation.push())
• Opening other dialogs or menus
• State updates that affect UI (setState, queryClient.invalidateQueries)
• Callbacks passed from parent components

The Menu component on iOS specifically uses this pattern - see src/components/Menu/index.tsx:151.

Controlled vs Uncontrolled Inputs

Prefer defaultValue over value for TextInput on the old architecture:

// Preferred - uncontrolled
<TextField.Input
  defaultValue={initialEmail}
  onChangeText={setEmail}
/>

// Avoid when possible - controlled (can cause performance issues)
<TextField.Input
  value={email}
  onChangeText={setEmail}
/>

Platform-Specific Behavior

Some components behave differently across platforms:

• Dialog.Handle - Only renders on native (drag handle for bottom sheet)
• Dialog.Close - Only renders on web (X button)
• Menu.Divider - Only renders on web
• Menu.ContainerItem - Only works on native

Always test on multiple platforms when using these components.

React Compiler is Enabled

This codebase uses React Compiler, so don't proactively add useMemo or useCallback. The compiler handles memoization automatically.

// UNNECESSARY - React Compiler handles this
const handlePress = useCallback(() => {
  doSomething()
}, [doSomething])

// JUST WRITE THIS
const handlePress = () => {
  doSomething()
}

Only use useMemo/useCallback when you have a specific reason, such as:

• The value is immediately used in an effect's dependency array
• You're passing a callback to a non-React library that needs referential stability

Best Practices

1. Accessibility: Always provide label prop for interactive elements, use accessibilityHint where helpful

2. Translations: Wrap ALL user-facing strings with msg() or <Trans>

3. Styling: Combine static atoms with theme atoms, use platform utilities for platform-specific styles

4. State: Use TanStack Query for server state, React Context for UI preferences

5. Components: Check if a component exists in #/components/ before creating new ones

6. Types: Define explicit types for props, use NativeStackScreenProps for screens

7. Testing: Components should have testID props for E2E testing

Key Files Reference

Purpose	Location
Theme definitions	src/alf/themes.ts
Design tokens	src/alf/tokens.ts
Static atoms	src/alf/atoms.ts (extends @bsky.app/alf)
Navigation config	src/Navigation.tsx
Route definitions	src/routes.ts
Route types	src/lib/routes/types.ts
Query hooks	src/state/queries/*.ts
Session state	src/state/session/index.tsx
i18n setup	src/locale/i18n.ts