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Overview

Ghost is Better Hub’s AI assistant, accessible with ⌘I from anywhere in the app. Ghost helps you review pull requests, navigate code, triage issues, write commit messages, and answer questions about repositories.

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Key Features

PR Reviews

Summarize changes, spot issues, and suggest improvements

Code Navigation

Find files, explain functions, trace dependencies

Issue Triage

Categorize, label, and draft responses to issues

Commit Messages

Generate conventional commit messages from diffs

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Opening Ghost

Ghost is available everywhere in Better Hub:

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Keyboard Shortcut

Press ⌘I (Mac) or Ctrl+I (Windows/Linux) to toggle Ghost from any page.

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Command Center

  1. Press ⌘K to open the command center
  2. Select “Open Ghost” from the suggestions

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Floating Button

Click the Ghost icon in the bottom-right corner (appears on repository pages).
Ghost opens in a slide-out panel on the right side of the screen, keeping your current page visible for context.

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Ghost Panel Interface

The Ghost panel has several key components:
  • Ghost icon: Indicates active AI session
  • Close button (X): Collapse the panel
  • Resize handle: Drag to adjust panel width

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Tab Bar

Ghost supports multiple tabs for parallel conversations:
  • Current tab: Shows the active conversation
  • Tab label: Auto-generated from page context (e.g., “PR #123 · repo-name”)
  • New tab (+): Start a fresh conversation
  • Close tab (X): Remove a tab (hover to reveal)
Use multiple tabs to switch between reviewing a PR and asking general repo questions without losing context.

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Chat Area

  • Messages: Your questions and Ghost’s responses
  • Code blocks: Syntax-highlighted with copy button
  • File links: Click to navigate to mentioned files
  • Suggestions: Contextual prompts to get started

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Input Box

  • Text field: Type your question or command
  • Mention files: Type @ to mention PR files or # to search repo files
  • Context chips: Shows attached code snippets (when you select code)
  • Send button: Submit your message

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Page-Aware Context

Ghost automatically understands where you are:
Ghost has access to:
  • All changed files and diffs
  • PR description
  • Comments and reviews
  • Commit messages
  • Related issues
Example prompts:
  • “Summarize this PR”
  • “Are there any security concerns?”
  • “What files should I review first?”

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Common Use Cases

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1. PR Review Assistance

When reviewing a pull request: 
You: Summarize this PR

Ghost: This PR adds user authentication using JWT tokens. 
Key changes:
- New AuthService in src/auth/service.ts
- Login/logout endpoints in src/routes/auth.ts  
- Token validation middleware in src/middleware/auth.ts

Potential concerns:
- Token expiration is set to 24 hours (line 45) - consider shorter
- No rate limiting on login endpoint
- Password requirements aren't enforced
Follow-up prompts:
  • “Show me the authentication flow”
  • “Are there any security issues?”
  • “What tests were added?”
  • “Check for error handling”

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2. Code Explanation

Understanding complex code: 
You: @src/utils/parser.ts explain the parseQuery function

Ghost: The parseQuery function takes a string query and converts it 
into a structured AST (Abstract Syntax Tree). It:

1. Tokenizes the input string (line 12-24)
2. Builds an AST using recursive descent parsing (line 26-58)
3. Validates syntax and throws errors for invalid queries (line 60-72)

It's used by the search feature to interpret user search queries.

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3. Issue Triage

Processing new issues: 
You: What labels should I add to this issue?

Ghost: Based on the description, I suggest:
- `bug` - User reports an error
- `priority:high` - Affects authentication (critical path)
- `needs-reproduction` - No repro steps provided yet

I'd also ask the author for:
- Browser version
- Steps to reproduce
- Error logs from console

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4. Commit Message Generation

When committing code: 
You: Generate a commit message for my changes

Ghost: Based on your diff:

feat(auth): add JWT token refresh mechanism

- Implement token refresh endpoint
- Add RefreshToken model and repository  
- Update AuthService to handle token renewal
- Add tests for refresh flow

Breaking change: Token expiration reduced from 24h to 2h

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5. File Navigation

Finding code in large repos: 
You: Where is the user authentication logic?

Ghost: User authentication is handled in:

📁 src/auth/
  - service.ts - Core AuthService class
  - middleware.ts - Request authentication  
  - strategies/ - Login strategies (local, OAuth)

📁 src/routes/
  - auth.ts - /login and /logout endpoints

Main entry point: src/auth/service.ts:AuthService.login()

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Mentioning Files

Attach specific files or code to your queries:

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@ Mentions (PR Files)

On a PR, type @ to mention files changed in the PR: 
You: @src/auth.ts does this handle rate limiting?
Ghost will analyze that specific file in context.

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# Mentions (Any Repo File)

Type # to search and mention any file in the repository: 
You: #config compare the staging and prod configs
A file picker appears - select the files you want to include.

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Multiple Files

You: @src/auth.ts @src/middleware.ts how do these interact?
Ghost analyzes both files and explains their relationship.

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Attaching Code Snippets

Select code in a diff or file view, then click “Ask AI”:
  1. Code snippet appears as a context chip in Ghost’s input
  2. Ask questions about that specific code:
    • “What does this do?”
    • “Is this secure?”
    • “Suggest improvements”
  3. Ghost references line numbers in its response
  4. Remove context chip with the X button
You can attach multiple code snippets from different files to ask comparative questions.

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Conversation History

Ghost saves your conversations:
  • Per-tab history: Each Ghost tab maintains its own conversation
  • Persistent: Conversations survive page navigation
  • Searchable: Click “History” to see past conversations
  • Loadable: Click a past conversation to restore it in a new tab

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Starting Fresh

To clear the current conversation:
  1. Click the ”+” button to open a new tab
  2. The new tab starts with a clean slate
  3. Close the old tab if you no longer need it

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Ghost Models

Better Hub uses different AI models for different tasks:
  • Default model: kimi-k2.5 (fast, context-aware)
  • Merge model: gemini-2.5-pro-preview (for PR merges)

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Changing the Model

  1. Press ⌘K → “Configuration” → “Model Settings”
  2. Select from available models:
    • GPT-4
    • Claude 3.5 Sonnet
    • Gemini 2.5 Pro
    • Kimi K2.5
  3. Each model has different strengths (speed, context size, reasoning)
Kimi K2.5 (default) - Best balance of speed and quality for most tasks.Claude 3.5 Sonnet - Best for code review and technical writing.GPT-4 - Best for general questions and explanations.Gemini 2.5 Pro - Best for very large context (huge PRs).

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Best Practices

Be specific: Instead of “review this PR”, ask “check this PR for security issues” or “explain the database changes”.
Use mentions: Reference specific files with @file or #file to focus Ghost’s attention.
Follow up: Ghost’s responses are conversational. Ask clarifying questions or request elaboration.
Multiple tabs: Keep separate conversations for different topics. One for PR review, one for debugging, etc.
Check sources: Ghost cites file paths and line numbers. Verify its suggestions by reviewing the actual code.

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Limitations

Ghost works best with:
  • PRs under 50 files changed
  • Text-based files (code, markdown, configs)
  • Repositories with clear structure
Ghost may struggle with:
  • Binary files or images
  • Very large monorepos (>10k files)
  • Generated code (minified JS, compiled output)

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Privacy & Security

  • Ghost analyzes code in your current session only
  • Conversations are not used to train models
  • Private repos remain private (Ghost uses your GitHub auth)
  • Self-hosted Better Hub: All AI processing can run on-premises
Yes! In Configuration → Settings, toggle “Use your own API key” and enter:
  • OpenRouter API key
  • Anthropic API key (optional)
  • OpenAI API key (optional)
You’ll be billed directly by the provider at their rates.

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Keyboard Shortcuts

ShortcutAction
⌘IToggle Ghost panel
⌘EnterSend message
EscClose Ghost
⌘TNew tab
⌘WClose current tab