Codex Mode for DeepSeek Harness

A Codex-style execution mode for DSH. It adds a switch at the top of the permission menu, keeps a durable plan, emits visible progress while tools run, and continues a turn that stops with unfinished work.

The important difference from a prompt-only mode: if the model emits a tool call without text, the host driver commits a short progress message before the tool runs, as part of the durable assistant message. A long turn is not a silent tool loop.

What it does

• Codex switch at the top of the permission menu, above a divider. The switch does not change the sandbox or approval level.
• Visible progress before every tool batch. The model's own commentary is kept; a missing one is inserted by the driver in the user's language.
• Turn continuation when the todo list still has unfinished work and the assistant is not asking a question.
• Durable state stored as a permission-preset identity (codex-read-only, codex-workspace-write, codex-danger-full-access), so it survives reload and resume and appears in the session log.
• Same safety gates for Full access and Auto review as the stock permission control.

Requirements

• DSH Desktop or Web with the Plugin Manager. Tested with DSH 0.2.1-rc.3.
• The package declares engines.dsh: ^0.2.1-rc.1; install it on a 0.2.1-rc.x runtime.
• Git and network access to GitHub for the first install.

Install

Option 1: give DSH the GitHub link

Start a new DSH session and send:

Install this DSH plugin bundle from GitHub: https://github.com/airainal/dsh-codex-mode

The agent can call the plugin_manager tool with that URL. The manager checks the GitHub repository, installs the bundle, and enables it. You can also open Plugins → Install bundle and paste:

https://github.com/airainal/dsh-codex-mode

If your DSH version wants an explicit git spec, use:

github:airainal/dsh-codex-mode

Option 2: install the release tarball

Download the asset from Releases and paste either the release asset URL or the downloaded .tgz path into Plugins → Install bundle:

https://github.com/airainal/dsh-codex-mode/releases/download/v1.0.0/dsh-codex-mode-1.0.0.tgz

After installing

1. Open any session.
2. Click the permission control at the bottom of the composer.
3. Turn on Codex Mode at the top of the menu.
4. Pick Read Only, Workspace Write, or Full access exactly as before. The mode and the permission level are independent.

HMR applies the change immediately in the desktop app. If your profile has HMR disabled, restart DSH after installation.

To remove it, open Plugins → Codex Mode → Remove, or ask the agent to remove the bundle.

Use

The menu has two dimensions:

• the Codex switch controls the execution protocol;
• the permission choices control the sandbox and approval policy.

Turning Codex on while Workspace Write is selected moves the session to the matching codex-workspace-write identity, but the sandbox stays workspace-write. Changing permission while the mode is on keeps the mode and moves to the matching codex-* variant.

The trigger shows a Codex mark on the right when the mode is on. It slides out with a 240 ms width/opacity transition, and the menu stays open while switching.

How it works

The package is a DSH bundle with a Host half and a Web client half.

• cordis.patch.yml adds the three codex-* permission presets and mounts the Host plugin.
• The Host plugin adds the codex:mode system-prompt section and wraps each live agent's step. In Codex mode, an assistant/message that contains only tool calls gets a leading progress text block before it is committed; the matching text-chunks record is added to the stream and tool-call block indexes are shifted so content and stream stay aligned.
• agent/turn-stopping provides one continuation steer when the plan is unfinished and the reply is not a question.
• The Client plugin replaces the current-session permission control with the same control plus the Codex row, keeping the original permission glyphs and the Full-access/Auto-review risk dialogs.

This is a Codex step driver, not a second tool runtime. DSH still owns turn construction, tool dispatch, approvals, retries, compaction, and the event log. A full fork of those systems would duplicate a large amount of tested infrastructure; the driver changes the part users actually see: progress output and turn continuation.

Why the progress line is provable

The line is not a UI status chip. In a test turn that explicitly told the model not to emit text, the model's stream contained only reasoning and tool-call chunks, with no text-chunks. The committed assistant message was:

[reasoning, "我先读取 `dsh-codex-mode/client.js`。", tool-call]

The matching stream indexes were reasoning 0, text 1, tool-call 2. The text could only come from the Host driver. The test was run locally against DSH 0.2.1-rc.3; the session log itself is not published.

Scope and limitations

• The package targets DSH 0.2.1-rc.x. It uses the live agent's step and the session append boundary; a future DSH release can change those internals.
• It is not a complete Codex engine. Freeform apply_patch, Codex-style one-tool scheduling, shell/output limits, and Codex compaction thresholds are not implemented.
• The bundle overrides the permission row to add the codex-* presets. If you maintain custom permission presets in a profile, carry them into cordis.patch.yml before installing.
• The built-in /permission command also lists the codex-* identities. Use the composer menu for the intended two-dimensional behavior.
• The Settings default-permission selector lists the codex-* presets because they are ordinary permission presets; the composer menu is the intended place to switch a running session.

Screenshots

Menu, light	Trigger

Dark risk gate	Narrow layout

Development

There is no build step.

git clone https://github.com/airainal/dsh-codex-mode.git
cd dsh-codex-mode

Install the directory as a bundle through Plugins → Install bundle, or ask a DSH agent to install that path with plugin_manager. The Host plugin exports apply(), the client is a plain window.__ModuleLoader__ module, and the bundle patch is cordis.patch.yml.

To build the release tarball:

pnpm pack

中文快速安装

把下面这句直接发给新的 DSH 会话：

安装这个 DSH 插件 bundle：https://github.com/airainal/dsh-codex-mode

装好后打开任意会话，点输入框下方的权限按钮，在菜单顶部打开 Codex 模式。 权限级别不会改变；Codex 模式关闭时，行为与原生 DSH 一致。

License

MIT. See LICENSE.