[High] Interactive Mode Enhancements

[marklicata]

Summary

Enhance interactive mode with input prefixes (! for bash, # for memory), vim keybindings, multi-line input support, and improved keyboard shortcuts.

Current State

Amplifier CLI interactive mode has basic prompt-toolkit integration but lacks:

• Input prefixes for quick actions
• Vim mode for efficient editing
• Multi-line input with backslash continuation
• Advanced keyboard shortcuts

Proposed Implementation

1. Input Prefixes

Prefix	Action	Example
!	Execute bash directly	!git status
#	Append to memory	# Remember: use pytest-asyncio
/	Slash command (exists)	/help
?	Quick help/search	?how do I run tests

amplifier> !ls -la
drwxr-xr-x  10 user  staff   320 Jan 15 10:30 src
-rw-r--r--   1 user  staff  1024 Jan 15 10:25 README.md

amplifier> # The project uses FastAPI 0.100+
[Added to session memory]

amplifier> ?pytest fixtures
[Quick search: "pytest fixtures" - showing brief answer]

2. Vim Mode

Enable vim keybindings in interactive mode:

# In amplifier.yaml
interactive:
  editing_mode: "vi"  # Options: "emacs" (default), "vi"

Or via CLI:

amplifier --vim
amplifier -V  # Short flag

Vim mode features:

• Normal/insert mode switching
• Motion commands (w, b, e, 0, $, etc.)
• Delete/change/yank operations
• Search within line
• Visual mode for selection

3. Multi-Line Input

Use backslash \ at end of line to continue:

amplifier> Create a Python function that \
... takes a list of numbers and \
... returns the sum of even numbers

[Processing multi-line input...]

Or use triple backticks for code blocks:

amplifier> ```
... def calculate_sum(numbers):
...     return sum(n for n in numbers if n % 2 == 0)
... ```
Please review this function.

[Processing with code block...]

4. Keyboard Shortcuts

Shortcut	Current	Proposed
Ctrl+C	Cancel	Cancel current (exists)
Ctrl+D	Exit	Exit if empty (exists)
Ctrl+L	-	Clear screen
Ctrl+R	-	Search history
Ctrl+Z	-	Undo last edit
Esc Esc	-	Rewind to checkpoint
Ctrl+K	-	Clear to end of line
Ctrl+U	-	Clear to start of line
Ctrl+W	-	Delete word backward
Tab	-	Autocomplete (paths, commands)
Up/Down	History	History (exists)
Ctrl+P/N	-	History (vim style)

5. Status Line

Add a persistent status line at bottom of terminal:

┌─────────────────────────────────────────────────────────────┐
│ amplifier> write a function to parse JSON                   │
│                                                             │
│ [AI response here...]                                       │
│                                                             │
├─────────────────────────────────────────────────────────────┤
│ claude-sonnet │ 15.2k/200k tokens │ $0.043 │ session: abc12 │
└─────────────────────────────────────────────────────────────┘

Status line shows:

• Current model
• Token usage (used/limit)
• Session cost
• Session ID (truncated)
• Optional: git branch, working directory

6. Autocomplete

Tab completion for:

• File paths (with fuzzy matching)
• Slash commands (/help, /clear, etc.)
• Tool names in prompts
• History search

amplifier> /he[TAB]
/help  /history

amplifier> look at src/[TAB]
src/main.py  src/utils/  src/api/

amplifier> !git [TAB]
status  commit  push  pull  branch  checkout

7. New Module Updates

src/amplifier_app_cli/ui/
├── interactive.py    # UPDATE - add prefixes, vim mode
├── keybindings.py    # NEW - custom key bindings
├── multiline.py      # NEW - multi-line input handling
├── autocomplete.py   # NEW - tab completion
├── statusline.py     # NEW - bottom status bar
└── prefixes.py       # NEW - prefix handlers (!, #, ?)

8. Core Interfaces

from prompt_toolkit.key_binding import KeyBindings
from prompt_toolkit.completion import Completer

class PrefixHandler(Protocol):
    prefix: str
    
    def matches(self, text: str) -> bool:
        """Check if input starts with this prefix."""
        return text.startswith(self.prefix)
    
    async def handle(self, text: str, session: Session) -> HandleResult:
        """Handle the prefixed input."""
        ...

@dataclass
class HandleResult:
    consumed: bool              # Was input fully handled?
    output: str | None          # Output to display
    continue_prompt: bool       # Should we prompt again?

class BashPrefixHandler(PrefixHandler):
    prefix = "!"
    
    async def handle(self, text: str, session: Session) -> HandleResult:
        command = text[1:].strip()
        result = subprocess.run(command, shell=True, capture_output=True)
        return HandleResult(
            consumed=True,
            output=result.stdout.decode(),
            continue_prompt=True
        )

class MemoryPrefixHandler(PrefixHandler):
    prefix = "#"
    
    async def handle(self, text: str, session: Session) -> HandleResult:
        memory_text = text[1:].strip()
        session.memory.append(memory_text)
        return HandleResult(
            consumed=True,
            output="[Added to session memory]",
            continue_prompt=True
        )

class AmplifierCompleter(Completer):
    def __init__(
        self,
        slash_commands: list[str],
        working_dir: Path,
        history: list[str]
    ): ...
    
    def get_completions(self, document, complete_event):
        """Provide context-aware completions."""
        ...

9. Configuration

interactive:
  # Editing mode
  editing_mode: "emacs"         # emacs | vi
  
  # Prefixes
  prefixes:
    bash: "!"
    memory: "#"
    quick_help: "?"
    
  # Status line
  status_line:
    enabled: true
    show_model: true
    show_tokens: true
    show_cost: true
    show_session_id: true
    
  # Multi-line
  multiline:
    continuation_char: "\\"
    code_block_delimiters: ["```", "'''"]
    
  # Autocomplete
  autocomplete:
    enabled: true
    fuzzy_paths: true
    min_chars: 2
    
  # History
  history:
    max_entries: 1000
    search_enabled: true
    persist: true

10. CLI Flags

# Enable vim mode
amplifier --vim
amplifier -V

# Disable status line
amplifier --no-status-line

# Disable autocomplete
amplifier --no-autocomplete

# Simple mode (no prefixes, no status line)
amplifier --simple

Acceptance Criteria

• ! prefix executes bash commands directly
• # prefix appends to session memory
• ? prefix provides quick help/search
• Vim mode works with common motions/operations
• Multi-line input with \ continuation
• Multi-line input with triple backticks
• Ctrl+L clears screen
• Ctrl+R searches history
• Esc Esc triggers checkpoint restore
• Tab completion for paths and commands
• Status line shows model, tokens, cost
• All features configurable via YAML
• All features toggleable via CLI flags
• Unit tests for prefix handlers
• Integration tests for interactive mode

Related

• Depends on: Memory Files (for # prefix)
• Depends on: Checkpointing (for Esc Esc)
• Enhances: User experience

Estimated Effort

Medium - 1.5-2 weeks

Files to Create/Modify

• src/amplifier_app_cli/ui/interactive.py (major updates)
• src/amplifier_app_cli/ui/keybindings.py (new)
• src/amplifier_app_cli/ui/multiline.py (new)
• src/amplifier_app_cli/ui/autocomplete.py (new)
• src/amplifier_app_cli/ui/statusline.py (new)
• src/amplifier_app_cli/ui/prefixes.py (new)