ACP - VSCode AI Agent Client

A feature-rich VSCode extension that connects AI coding CLIs via the Agent Client Protocol (ACP) to enable AI agent programming. The extension supports ACP-protocol CLI tools such as OpenCode, Claude Code, Codex, and more. Switch models, agents, view sub-agent context, and manage sessions — all from your VSCode sidebar. 100% of the code is implemented through AI agent programming using the OpenCode CLI tool.

Features

Agent Discovery — Browse and install ACP-compatible agents from the official registry
Agent Selector — Connect to any ACP-compatible CLI (OpenCode, Claude, etc.)
Model & Thought Level Switching — Change model and thinking depth on the fly
Session Management — Create, switch, resume, and close chat sessions
Streaming Messages — Real-time message streaming with Markdown + code highlighting
Tool Call Cards — Expandable cards showing tool calls with arguments and results
Sub-Agent Views — Inspect sub-agent conversations inline
Slash Commands — /model, /think, /agent, /clear, /help

Getting Started

Prerequisites

VSCode 1.85+
An ACP-compatible CLI installed (e.g., OpenCode)

Installation

Load the .vsix file manually (not yet published to the VSCode Marketplace)
Open Settings → search for ACP
Configure your agents in vscodeAcp.agents

Configuration

Add agents to your VSCode settings:

{
  "vscodeAcp.agents": [
    {
      "id": "opencode",
      "name": "OpenCode",
      "command": "opencode",
      "args": ["acp"],
      "env": {}
    }
  ],
  "vscodeAcp.defaultAgent": "opencode"
}

Agent Configuration Fields

Field	Required	Description
`id`	Yes	Unique identifier for the agent
`name`	Yes	Display name shown in the UI
`command`	Yes	CLI command to start the agent
`args`	No	Command-line arguments
`env`	No	Environment variables passed to the process

Supported Agents

OpenCode

OpenCode natively supports ACP via the acp subcommand.

Prerequisites: Install OpenCode (npm install -g opencode-ai or download from releases)

{
  "vscodeAcp.agents": [
    {
      "id": "opencode",
      "name": "OpenCode",
      "command": "opencode",
      "args": ["acp"],
      "env": {}
    }
  ]
}

Claude Code

Claude Code requires the @zed-industries/claude-code-acp adapter to work with ACP clients.

Prerequisites:

Install Claude Code: npm install -g @anthropic-ai/claude-code
Authenticate: claude setup-token
Install the ACP adapter: npm install -g @zed-industries/claude-code-acp

{
  "vscodeAcp.agents": [
    {
      "id": "claude",
      "name": "Claude Code",
      "command": "claude-code-acp",
      "args": [],
      "env": {
        "ANTHROPIC_API_KEY": "sk-ant-..."
      }
    }
  ]
}

Note: If you have already authenticated via claude setup-token, you can omit the ANTHROPIC_API_KEY environment variable. The adapter will use the existing Claude Code session.

Codex CLI

Codex CLI requires the codex-acp adapter for ACP compatibility.

Prerequisites:

Install Codex CLI from OpenAI
Install the ACP adapter: follow instructions at cola-io/codex-acp

{
  "vscodeAcp.agents": [
    {
      "id": "codex",
      "name": "Codex",
      "command": "codex-acp",
      "args": [],
      "env": {
        "OPENAI_API_KEY": "sk-..."
      }
    }
  ]
}

Gemini CLI

Gemini CLI natively supports ACP via the --acp flag.

Prerequisites: Install Gemini CLI (npm install -g @anthropic-ai/gemini-cli or follow Google's instructions)

{
  "vscodeAcp.agents": [
    {
      "id": "gemini",
      "name": "Gemini",
      "command": "gemini",
      "args": ["--acp"],
      "env": {}
    }
  ]
}

Multiple Agents

You can configure multiple agents and switch between them from the sidebar:

{
  "vscodeAcp.agents": [
    {
      "id": "opencode",
      "name": "OpenCode",
      "command": "opencode",
      "args": ["acp"],
      "env": {}
    },
    {
      "id": "claude",
      "name": "Claude Code",
      "command": "claude-code-acp",
      "args": [],
      "env": {}
    },
    {
      "id": "codex",
      "name": "Codex",
      "command": "codex-acp",
      "args": [],
      "env": {
        "OPENAI_API_KEY": "sk-..."
      }
    }
  ],
  "vscodeAcp.defaultAgent": "opencode"
}

Usage

Open the ACP Agent sidebar from the activity bar
Select an agent from the dropdown (connects automatically on first use)
A new session is created automatically
Type messages and press Enter to send (Shift+Enter for newline)
Use / prefix to access slash commands
Click the Model or Think buttons to change config options

Commands

Command	Description
`ACP: Discover Agents`	Browse and install agents from the ACP registry
`ACP: Select Agent`	Switch between configured agents
`ACP: New Session`	Create a new chat session
`ACP: Switch Session`	Switch to an existing session
`ACP: Select Model`	Change the current model
`ACP: Set Thought Level`	Adjust thinking depth
`ACP: Open Settings`	Open ACP settings

Development

# Install dependencies
npm install

# Build extension
npm run build

# Build webview
npm run build:webview

# Build everything
npm run build:all

# Run tests
npm test

# Watch mode (extension)
npm run watch

# Watch mode (webview)
npm run watch:webview

# Lint
npm run lint

# Package as .vsix
npm run package

Architecture

src/
├── extension/       # VSCode extension host
│   ├── index.ts     # Activation, lifecycle, wiring
│   ├── StateManager.ts
│   ├── ConfigurationManager.ts
│   ├── WebviewBridge.ts
│   ├── commands/    # VSCode commands
│   └── views/       # SidebarProvider, StatusBar
├── protocol/        # ACP protocol layer
│   ├── AgentConnection.ts
│   └── AgentRegistry.ts
├── shared/          # Shared types & utilities
│   ├── types/
│   └── EventEmitter.ts
└── webview/         # React webview UI
    ├── api/         # VSCode API bridge
    ├── store/       # Zustand state
    ├── components/  # React components
    └── App.tsx

License

MIT

VSACP

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