OpenCode GUI Chat

A general-purpose AI assistant inside Visual Studio Code.

OpenCode GUI Chat brings an agentic AI assistant into VS Code's native chat UI. Use it for coding, documentation, data analysis, research, and automation with any OpenAI-compatible endpoint (LiteLLM, DeepSeek, vLLM, Ollama, or an internal gateway). No terminal required.

Highlights

Requirements

• VS Code 1.80 or later.
• An OpenAI-compatible endpoint and API key.
• Optional: OpenCode CLI for browsing CLI session history.
• Local MCP servers need their runtime (Node.js/npx, Python/uvx, ...).

Installation

Marketplace

1. Open Extensions (Ctrl+Shift+X).
2. Search for OpenCode GUI Chat.
3. Click Install and reload if prompted.

code --install-extension thuyennv.opencode-gui-chat

VSIX

code --install-extension opencode-gui-chat-1.0.4.vsix

Or use Extensions → ... → Install from VSIX.... The OpenCode icon appears in the Activity Bar or Secondary Side Bar.

First-time setup

1. Open a workspace folder.
2. Press Ctrl+Alt+O (macOS: Cmd+Alt+O).
3. Configure an endpoint using one of the options below, then select a model and send a test message.

Option 1: opencode.jsonc (recommended)

If you use the OpenCode CLI, the extension reads the same merged config:

{
  "provider": {
    "my-provider": {
      "options": {
        "baseURL": "https://litellm.example.com",
        "apiKey": "sk-...",
      },
      "models": {
        "my-model": {
          "limit": { "context": 128000, "output": 8192 },
        },
      },
    },
  },
  "model": "my-provider/my-model",
}

Global config at ~/.config/opencode/opencode.json(c) is also loaded.

Option 2: VS Code Settings

Search for opencode in Settings:

Option 3: Secure API key

Run OpenCode: Set API Key from the Command Palette. The key is stored in VS Code Secret Storage, not in a config file.

Usage

Toolbar

The chat can also open in an editor group via OpenCode: Open Chat in Editor Group.

Composer syntax

Summarize docs/requirements.md in 10 bullets.
@data/sales.csv find the 3 biggest monthly anomalies.
@src/extension.ts find bugs when no workspace is open.

Commands

Custom commands load from .opencode/command/ and .claude/commands/.

Modes

Agents with mode: primary appear as additional modes.

Permissions

The extension applies the permission block from the merged opencode.json(c) to create, edit, bash, read, list, and grep.

For pattern rules, the last match wins. Put "*" first, then specific rules:

{
  "permission": {
    "create": "allow",
    "edit": { "*": "ask", "docs/**": "allow", "**/*.env": "deny" },
    "bash": { "*": "ask", "git *": "allow", "rm *": "deny" },
  },
}

create applies when write_file creates a new file; overwriting or editing an existing file uses edit. If create is unset, it falls back to edit.

Permissions can be overridden per agent in opencode.json or agent frontmatter:

{
  "agent": {
    "build": { "permission": { "bash": { "*": "ask", "git *": "allow" } } },
  },
}

Without a permission config, the safe defaults are create/edit/bash = ask and read operations = allow. Plan and Review are always read-only. MCP tool access is controlled by the MCP server.

Sessions and history

• Each workspace has its own session list in Chats.
• History shows sessions stored by the OpenCode CLI (CLI required).
• /export saves a conversation as Markdown; /compact reduces context.

Skills, agents, and workspace instructions

A skill is a folder containing SKILL.md. Agents and commands are Markdown files that support frontmatter such as name, description, agent, model, and permission. AGENTS.md or CLAUDE.md at the workspace root is added to the system prompt.

MCP

{
  "mcp": {
    "remote-tools": {
      "type": "remote",
      "url": "https://example.com/mcp",
      "headers": { "Authorization": "Bearer <token>" },
      "enabled": true,
    },
    "local-tools": {
      "type": "local",
      "command": ["npx", "tsx", "D:/tools/my-mcp/src/index.ts"],
      "environment": { "API_TOKEN": "<token>" },
      "enabled": true,
    },
  },
}

• local uses stdio; remote uses Streamable HTTP.
• Set enabled: false to disable a server.
• Tools appear as mcp_<server>_<tool>.
• A failing server does not block chat; use the MCP modal to reconnect.

Configuration

Configuration files are merged in order; later files win:

1. $OPENCODE_CONFIG
2. $OPENCODE_CONFIG_DIR/opencode.json(c)
3. $XDG_CONFIG_HOME/opencode/opencode.json(c) (default ~/.config/opencode/)
4. <workspace>/opencode.json(c)

API key lookup:

1. provider.<id>.options.apiKey
2. $XDG_DATA_HOME/opencode/auth.json (from opencode auth login)
3. VS Code Secret Storage (Key button)

limit.context sets the context meter denominator; limit.output sets max_tokens per response (overridden by opencode.maxTokens). Use OpenCode: Show Resolved Config to inspect the merged config.

Context

Click the context meter or run /context to see the system prompt, tool schemas, messages, tool output, estimated tokens, and remaining context. Use /compact or /new when context is nearly full.

Security and privacy

• Messages, attached files, and tool results go only to the endpoint you configure.
• The extension has no sharing feature and does not send data to opencode.ai. Sessions are stored locally in VS Code storage.
• share in opencode.jsonc only affects the OpenCode CLI; the extension does not use it.
• API keys saved via OpenCode: Set API Key are protected by VS Code Secret Storage.
• Avoid committing keys to opencode.jsonc or settings.json.
• No telemetry or third-party analytics.

Troubleshooting

Support

Report bugs or request features through the Q&A section on the Marketplace page. Include the extension/VS Code versions, provider and model (without the API key), the error message, and reproduction steps.

OpenCode GUI Chat — one assistant, every task.