Codex UI (VS Code Extension)

Use Codex-style CLIs inside VS Code: sessions, chat, tools, diffs.

This extension:

• Starts / connects to a backend per workspace folder
• Manages sessions (create, switch, rename, hide)
• Renders chat output and tool activity (commands, file changes, diffs, approvals)

Supported backends

You can choose a backend per session:

• codex: upstream Codex CLI (via codex app-server)
• opencode: OpenCode (via opencode serve)

Important notes:

• codex and opencode use different history formats/protocols. History is not shared across these backends, and sessions are kept separate.

Prerequisites

This extension does not bundle any CLI. Install the backends you want to use and make sure they are available in your PATH:

• codex >= 0.110.0 (for the codex backend)
• opencode (for the opencode backend)

Or set absolute paths via settings (see below).

Usage

1. Open the Activity Bar view: Codex UI
2. Click New to create a session (you can pick codex / opencode)
3. Type in the input box (Enter = send, Shift+Enter = newline)
4. Switch sessions from Sessions or the chat tab bar

Feature notes

• Rewind/Edit: supported for codex and opencode sessions.
• Accounts / login UI: available on codex sessions (opencode does not use the same account flow).
• Account create/switch (account/list, account/switch) is not supported in this extension.
• Fast tier: use /fast to switch the codex session service tier (fast, flex, or default).
• Plugins: use /plugins install <marketplace> <plugin> on codex sessions.
• OpenCode tool output: rendered as Step/Tool cards optimized to avoid tool-spam.

Settings

• codex.cli.commands.codex
  • Default: codex
  • If codex is not in your PATH, set an absolute path.
• codex.backend.args
  • Default: ["app-server"]
  • Arguments passed to the codex backend command.
• codex.opencode.command
  • Default: opencode
• codex.opencode.args
  • Default: ["serve"]
  • Arguments passed to the opencode backend command.

Development

1. Install dependencies

   pnpm install
   

2. (Re)generate protocol bindings (if missing / after protocol changes)

   cd ../codex-rs && cargo build -p codex-cli
   cd ../vscode-extension && pnpm run regen:protocol
   

3. Build

   pnpm run compile
   

4. Run in VS Code

   • Open this repo in VS Code
   • Run the debug configuration: Run Extension (Codex UI)

Publishing (VS Code Marketplace)

1. Update package.json (version)

2. Package

   pnpm run vsix:package
   

3. Publish

   pnpm run vsce:publish
   

Note: --no-dependencies を付けると、.vscodeignore で opt-in していても node_modules/ が VSIX に入らず、 起動時に Cannot find module でクラッシュします（少なくとも @iarna/toml / shell-quote が必要）。

Specification

See docs/spec.md.

Support

If you find this extension useful, you can support development via Buy Me a Coffee:

• https://buymeacoffee.com/harukary7518