Multica

A GUI client for ACP-compatible coding agents.

Multica uses the Agent Client Protocol (ACP) to communicate with various coding agents like OpenCode, Codex, and Gemini CLI.

Supported Agents

Agent	Command	Install
OpenCode	opencode acp	go install github.com/opencode-ai/opencode@latest
Codex CLI (ACP)	codex-acp	npm install -g codex-acp
Gemini CLI	gemini acp	npm install -g @google/gemini-cli

Quick Start

# Install dependencies
pnpm install

# Check which agents are installed
pnpm cli doctor

# Start interactive mode
pnpm cli

CLI

Multica includes a comprehensive CLI for testing and interacting with agents:

pnpm cli                          # Interactive mode
pnpm cli prompt "message"         # One-shot prompt
pnpm cli sessions                 # List sessions
pnpm cli resume <id>              # Resume session
pnpm cli agents                   # List available agents
pnpm cli doctor                   # Check agent installations

Interactive Mode

Start an interactive REPL session:

pnpm cli

Available commands:

Command	Description
/help	Show help
/new [cwd]	Create new session (default: current directory)
/sessions	List all sessions
/resume <id>	Resume session by ID prefix
/delete <id>	Delete a session
/history	Show current session message history
/agent <name>	Switch to a different agent
/agents	List available agents
/doctor	Check agent installations
/status	Show current status
/cancel	Cancel current request
/quit	Exit CLI

One-Shot Prompt

Send a single prompt and exit:

pnpm cli prompt "What is 2+2?"
pnpm cli prompt "List files" --cwd=/tmp

Doctor

Check if agents are installed on your system:

pnpm cli doctor

Shows installation status, binary path, version, and install hints for missing agents.

Options

Option	Description
--cwd=PATH	Working directory for the agent
--log	Save session log to logs/ directory
--log=PATH	Save session log to specified file

Cancellation

• Press Ctrl+C once to send a cancel request to the agent
• Press Ctrl+C twice to force quit

Development

# Start Electron app in dev mode
pnpm dev

# Type check
pnpm typecheck

Build

pnpm build:mac      # macOS
pnpm build:win      # Windows
pnpm build:linux    # Linux

Architecture

Multica (Electron)
├── Renderer Process (React)
│   └── UI Components (Chat, Settings, etc.)
│
├── Main Process
│   ├── Conductor (orchestrates agent communication)
│   │   ├── SessionStore (session persistence)
│   │   └── ClientSideConnection (ACP SDK)
│   │         └── AgentProcess (subprocess management)
│   │               └── opencode/codex-acp/gemini (stdio)
│   │
│   └── IPC Handlers (session, agent, config)
│
└── Preload (contextBridge)
    └── electronAPI (exposed to renderer)

Session Management

Multica maintains its own session layer on top of ACP:

~/.multica/sessions/
├── index.json              # Session list (fast load)
└── data/
    └── {session-id}.json   # Full session data + updates

Key design decisions:

• Client-side storage: Multica stores raw session/update data for UI display
• Agent-agnostic: Each agent manages its own internal state separately
• Resume behavior: Creates new ACP session, displays stored history in UI

IPC API

// Session management
electronAPI.createSession(cwd)
electronAPI.listSessions(options?)
electronAPI.getSession(id)
electronAPI.resumeSession(id)
electronAPI.deleteSession(id)

// Agent control
electronAPI.startAgent(agentId)
electronAPI.stopAgent()
electronAPI.sendPrompt(sessionId, content)
electronAPI.cancelRequest(sessionId)

License

MIT