bifrost/CLAUDE.md

Bifrost Fediverse Client - Development Plan

Project Overview

Bifrost is a fully accessible fediverse client built with PySide6, designed specifically for screen reader users. The application uses "post/posts" terminology instead of "toot" and focuses on excellent keyboard navigation and audio feedback.

Core Features

• Full ActivityPub protocol support (Pleroma and GoToSocial primary targets)
• Threaded conversation navigation with collapsible tree view
• Comprehensive soundpack management system with secure repository support
• Smart autocomplete for mentions (@user@instance.com) and emojis (5,000+ Unicode)
• Auto-refresh with intelligent activity-based timing
• Screen reader optimized interface with Orca compatibility fixes
• XDG Base Directory specification compliance

Technology Stack

• PySide6: Main GUI framework (proven accessibility with existing doom launcher)
• requests: HTTP client for ActivityPub APIs
• simpleaudio: Cross-platform audio with subprocess fallback
• emoji: Comprehensive Unicode emoji library (5,000+ emojis with keyword search)
• plyer: Cross-platform desktop notifications
• XDG directories: Configuration and data storage

Architecture

Directory Structure

bifrost/
├── bifrost/
│   ├── __init__.py
│   ├── main.py                 # Application entry point
│   ├── accessibility/          # Accessibility widgets and helpers
│   │   ├── __init__.py
│   │   ├── accessible_tree.py  # AccessibleTreeWidget for conversations
│   │   └── accessible_combo.py # Enhanced ComboBox from doom launcher
│   ├── activitypub/            # Federation protocol handling
│   │   ├── __init__.py
│   │   ├── client.py           # Main ActivityPub client
│   │   ├── pleroma.py          # Pleroma-specific implementation
│   │   └── gotosocial.py       # GoToSocial-specific implementation
│   ├── models/                 # Data models
│   │   ├── __init__.py
│   │   ├── post.py             # Post data structure
│   │   ├── user.py             # User profiles
│   │   ├── timeline.py         # Timeline model for QTreeView
│   │   └── thread.py           # Conversation threading
│   ├── widgets/                # Custom UI components
│   │   ├── __init__.py
│   │   ├── timeline_view.py    # Main timeline widget with auto-refresh
│   │   ├── compose_dialog.py   # Post composition with smart autocomplete
│   │   ├── autocomplete_textedit.py # Mention and emoji autocomplete system
│   │   ├── settings_dialog.py  # Application settings
│   │   ├── soundpack_manager_dialog.py # Soundpack repository management
│   │   └── login_dialog.py     # Instance login
│   ├── audio/                  # Sound system
│   │   ├── __init__.py
│   │   ├── sound_manager.py    # Audio notification handler
│   │   └── soundpack_manager.py # Secure soundpack installation system
│   │   └── sound_pack.py       # Sound pack management
│   └── config/                 # Configuration management
│       ├── __init__.py
│       ├── settings.py         # Settings handler with XDG compliance
│       └── accounts.py         # Account management
├── sounds/                     # Sound packs directory
│   ├── default/
│   │   ├── pack.json
│   │   ├── private_message.wav
│   │   ├── mention.wav
│   │   ├── boost.wav
│   │   ├── reply.wav
│   │   ├── post_sent.wav
│   │   ├── timeline_update.wav
│   │   └── notification.wav
│   └── doom/                   # Example themed sound pack
│       ├── pack.json
│       └── *.wav files
├── tests/
│   ├── __init__.py
│   ├── test_accessibility.py
│   ├── test_activitypub.py
│   └── test_audio.py
├── requirements.txt
├── setup.py
└── README.md

XDG Directory Usage

• Config: ~/.config/bifrost/ - Settings, accounts, current sound pack
• Data: ~/.local/share/bifrost/ - Sound packs, cached data
• Cache: ~/.cache/bifrost/ - Temporary files, avatar cache

Accessibility Implementation

From Doom Launcher Success

• AccessibleComboBox: Enhanced keyboard navigation (Page Up/Down, Home/End)
• Proper Accessible Names: All widgets get descriptive setAccessibleName()
• Focus Management: Clear tab order and focus indicators
• No Custom Speech: Screen reader handles all announcements

Threaded Conversation Navigation

Navigation Pattern:

Timeline Item: "Alice posted: Hello world (3 replies, collapsed)"
[Right Arrow] → "Alice posted: Hello world (3 replies, expanded)"
[Down Arrow] → "    Bob replied: Hi there"
[Down Arrow] → "    Carol replied: How's it going?"
[Down Arrow] → "David posted: Another topic"

Key Behaviors:

• Right Arrow: Expand thread, announce "expanded"
• Left Arrow: Collapse thread, announce "collapsed"
• Down Arrow: Next item (skip collapsed children)
• Up Arrow: Previous item
• Page Down/Up: Jump 5 items
• Home/End: First/last item

AccessibleTreeWidget Requirements

• Inherit from QTreeWidget
• Override keyPressEvent for custom navigation
• Proper accessibility roles and states
• Focus management for nested items
• Status announcements via Qt accessibility

Sound System Design

Sound Events

• startup: Application started
• shutdown: Application closing
• private_message: Direct message received
• mention: User mentioned in post
• boost: Post boosted/reblogged
• reply: Reply to user's post
• post_sent: User successfully posted
• timeline_update: New posts in timeline
• notification: General notification
• expand: Thread expanded
• collapse: Thread collapsed
• success: General success feedback
• error: Error occurred

Sound Pack Structure

pack.json Format:

{
  "name": "Pack Display Name",
  "description": "Pack description",
  "author": "Creator name",
  "version": "1.0",
  "sounds": {
    "private_message": "filename.wav",
    "mention": "filename.wav",
    "boost": "filename.wav",
    "reply": "filename.wav",
    "post_sent": "filename.wav",
    "timeline_update": "filename.wav",
    "notification": "filename.wav"
  }
}

SoundManager Features

• simpleaudio for cross-platform WAV playback with volume control
• Subprocess fallback (sox/play on Linux, afplay on macOS, PowerShell on Windows)
• Fallback to default pack if sound missing
• Master volume and notification volume controls
• Enable/disable per event
• Pack discovery and validation
• Smart threading (direct calls for simpleaudio, threaded for subprocess)

ActivityPub Implementation

Core Client Features

• Timeline Streaming: Real-time updates via WebSocket/polling
• Post Composition: Text, media attachments, visibility settings
• Thread Resolution: Fetch complete conversation trees
• User Profiles: Following, followers, profile viewing
• Notifications: Mentions, boosts, follows, favorites

Server Compatibility

Primary Targets:

• Pleroma: Full feature support
• GoToSocial: Full feature support

Extended Support:

• Mastodon: Best effort compatibility
• Other ActivityPub servers: Basic functionality

API Endpoints Usage

• /api/v1/timelines/home - Home timeline
• /api/v1/statuses - Post creation
• /api/v1/statuses/:id/context - Thread fetching
• /api/v1/streaming - Real-time updates
• /api/v1/notifications - Notification management

User Interface Design

Main Window Layout

[Menu Bar]
[Instance/Account Selector]
[Timeline Tree View - Main Focus]
[Compose Box]
[Status Bar]

Key UI Components

• Timeline View: AccessibleTreeWidget showing posts and threads with pagination
• Timeline Tabs: Home, Mentions, Local, Federated timeline switching
• Compose Dialog: Modal for creating posts with accessibility
• Settings Dialog: Sound pack, desktop notifications, accessibility options
• Login Dialog: Instance selection and authentication
• URL Selection Dialog: Choose from multiple URLs in posts
• Context Menu: Copy, URL opening, reply, boost, favorite actions

Keyboard Shortcuts

• Ctrl+N: New post
• Ctrl+R: Reply to selected post
• Ctrl+B: Boost selected post
• Ctrl+F: Favorite selected post
• Ctrl+C: Copy selected post to clipboard
• Ctrl+U: Open URLs from selected post in browser
• F5: Refresh timeline
• Ctrl+,: Settings
• Escape: Close dialogs

Development Phases

Phase 1: Foundation

1. Project structure setup
2. XDG configuration system
3. Basic PySide6 window with accessibility
4. AccessibleTreeWidget implementation
5. Sound system foundation

Phase 2: ActivityPub Core

1. Basic HTTP client
2. Authentication (OAuth2)
3. Timeline fetching and display
4. Post composition and sending
5. Basic thread display

Phase 3: Advanced Features

1. Thread expansion/collapse
2. Real-time updates
3. Notifications system
4. Sound pack system
5. Settings interface

Phase 4: Polish

1. Comprehensive accessibility testing
2. Screen reader testing (Orca, NVDA, JAWS)
3. Performance optimization
4. Error handling
5. Documentation

Testing Strategy

Accessibility Testing

• Automated testing with screen reader APIs
• Manual testing with Orca, NVDA (via Wine)
• Keyboard-only navigation testing
• Focus management verification

Functional Testing

• ActivityPub protocol compliance
• Thread navigation accuracy
• Sound system reliability
• Configuration persistence

Test Instances

• Pleroma test server
• GoToSocial test server
• Mock ActivityPub server for edge cases

Configuration Management

Settings Structure

[general]
instance_url = https://example.social
username = user
timeline_refresh_interval = 60

[audio]
sound_pack = Doom
master_volume = 100
notification_volume = 100

[sounds]
private_message_enabled = true
private_message_volume = 0.8
mention_enabled = true
mention_volume = 1.0
# ... other sound settings

[notifications]
enabled = true
direct_messages = true
mentions = true
boosts = false
favorites = false
follows = true
timeline_updates = false

[timeline]
posts_per_page = 40

[accessibility]
announce_thread_state = true
auto_expand_mentions = false
keyboard_navigation_wrap = true
page_step_size = 5
verbose_announcements = true

Account Storage

• Secure credential storage
• Multiple account support
• Instance-specific settings

Known Challenges and Solutions

ActivityPub Complexity

• Challenge: Different server implementations vary
• Solution: Modular client design with server-specific adapters

Screen Reader Performance

• Challenge: Large timelines may impact performance
• Solution: Virtual scrolling, lazy loading, efficient tree models

Thread Visualization

• Challenge: Complex thread structures hard to navigate
• Solution: Clear indentation, status announcements, skip collapsed

Sound Customization

• Challenge: Users want different audio feedback
• Solution: Comprehensive sound pack system with easy installation

Future Enhancements

Advanced Features

• Custom timeline filters
• Multiple column support
• Direct message interface
• List management
• Advanced search

Accessibility Extensions

• Braille display optimization
• Voice control integration
• High contrast themes
• Font size scaling

Federation Features

• Cross-instance thread following
• Server switching
• Federation status monitoring
• Custom emoji support

Dependencies

Core Requirements

PySide6>=6.0.0
requests>=2.25.0
simpleaudio>=1.0.4
plyer>=2.1.0
emoji>=2.0.0

Optional Dependencies

pytest (testing)
coverage (test coverage)
black (code formatting)
mypy (type checking)

Installation and Distribution

Development Setup

git clone <repository>
cd bifrost
pip install -r requirements.txt
# Run with proper display
DISPLAY=:0 ./bifrost.py
# Or
python bifrost.py

Packaging

• Python wheel distribution
• AppImage for Linux
• Consideration for distro packages

Accessibility Compliance

Standards Adherence

• WCAG 2.1 AA compliance
• Qt Accessibility framework usage
• AT-SPI2 protocol support (Linux)
• Platform accessibility APIs

Screen Reader Testing Matrix

• Orca (Linux): Primary target
• NVDA (Windows via Wine): Secondary
• JAWS (Windows via Wine): Basic compatibility
• VoiceOver (macOS): Future consideration

Critical Accessibility Rules

Text Truncation Is Forbidden

NEVER TRUNCATE TEXT: Bifrost is an accessibility-first client. Text truncation (using "..." or limiting character counts) is strictly forbidden as it prevents screen reader users from accessing complete information. Always display full content, descriptions, usernames, profiles, and any other text in its entirety.

Examples of forbidden practices:

• content[:100] + "..."
• Character limits on display text
• Shortened usernames or descriptions
• Abbreviated profile information

This document serves as the comprehensive development guide for Bifrost, ensuring all accessibility, functionality, and architectural decisions are preserved and can be referenced throughout development.