Codex Conversations for DeepSeek Harness

Release candidate 0.2.3-rc.2 is verified on official DSH 0.1.5-rc.2 and 0.1.6-alpha.1. It accepts both durable and live Assistant streams, both persistence read response shapes, and the settlement metadata required by the newer DSH contract; its peer metadata declares both exact releases. Install it from npm · Compatibility evidence.

Release channels: latest → 0.2.2; next → 0.2.3-rc.2.

npx @deepseek-ai/[email protected] plugin --profile web add relay-dsh-plugin-codex@next
npx @deepseek-ai/[email protected] web

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npm package: relay-dsh-plugin-codex
· All Relay DSH plugins

Run Codex inside official DeepSeek Harness without switching interfaces or
maintaining a DSH fork.

relay-dsh-plugin-codex adds Codex as a native conversation backend to the
official DeepSeek Harness
(DSH) Web UI. You keep DSH's workspace, conversation history, composer,
approvals, and tools while each DSH Session continues one Codex App Server
Thread. The plugin installs independently; no Relay checkout is required.

Try It on Official DSH

Authenticate with an official Codex client before the first Session. Codex CLI
users can run:

codex login

The install requires Node.js 22.13 or newer and pnpm on PATH. Stop DSH Web,
install the stable plugin, and restart DSH:

npx @deepseek-ai/[email protected] plugin --profile web add relay-dsh-plugin-codex@latest
npx @deepseek-ai/[email protected] web

Open New Session, select a workspace, choose Codex from the mode menu,
and send a message.

The screenshot was captured from official DSH 0.1.1-rc.2 with the Codex and
Claude plugins installed. If you install only this plugin, only Codex is
added.

Watch Plugin Manager find and install this package in 40 seconds
· review all Relay DSH plugins

If this removes an interface switch from your DSH workflow,
star this plugin and
share your DSH version or install feedback.
That signal helps other DSH users find a tested Codex backend.

Do I Need This Plugin?

Install it when you want to:

• use Codex inside DSH instead of switching to a separate Codex interface;
• keep DSH's native conversation history, composer, approvals, and questions;
• let one DSH Session continue the same Codex App Server Thread across turns;
• use Codex models, reasoning effort, images, interruption, and DSH-contributed
  tools in the same conversation.

You do not need it to use DSH's standard agents. It also does not add Relay
Events, file browsing, or a terminal panel. Those are separate optional plugins.

Complete Setup and Compatibility

The steps below were validated with:

• DeepSeek Harness 0.1.1-rc.2, commit
  b150a551
• Node.js 22.13 or newer
• pnpm available on PATH

DSH is currently a developer preview and may introduce compatibility-breaking
changes. This repository tracks official releases and records its tested version
here.

1. Prepare Codex authentication

The plugin installs a pinned official @openai/codex runtime and launches it in
App Server mode. The runtime contains native binaries for macOS, Windows, and
Linux on x64 and arm64, so DSH does not need to find a codex command on its
PATH.

Codex authentication is still required. Install or open an official Codex
client and authenticate it before starting your first DSH Codex session. When
using the CLI, verify the shared local credentials with:

codex --version
codex login

See the official Codex CLI guide and
authentication documentation for
installation and sign-in options. Credentials stay under Codex's normal local
authentication mechanism; this plugin does not collect them. Installing this
plugin supplies its App Server runtime, but does not add a global codex shell
command.

2. Choose a package source and install

Stop a running DSH Web process before changing Profile bundles. Choose one of
the following sources.

Stable npm release

The published npm package name is
relay-dsh-plugin-codex.
Use @latest to install the current stable release:

npx @deepseek-ai/[email protected] plugin --profile web add relay-dsh-plugin-codex@latest

At the time of writing, latest resolves to stable version 0.2.2. The linked
npm page is the source of truth for the current version.

npm prerelease (recommended during DSH preview)

Use @next to try the newest release candidate that has passed the repository's
CI publishing and official DSH compatibility checks. The current candidate also
contains the bundled cross-platform App Server runtime, so DSH does not depend
on a global codex executable:

npx @deepseek-ai/[email protected] plugin --profile web add relay-dsh-plugin-codex@next

The next tag points to 0.2.3-rc.2; latest points to 0.2.2.
Check the npm registry for the currently published dist-tag before installing.

This prerelease preserves native service-tier and resumed-thread settings, stops
late commands belonging to canceled turns, rejects stale interaction replies, and
retains dynamic-tool errors. New conversations receive bounded execution guidance;
set codexExecutionGuidance: false to disable it, or codexExecutionMode: native
to compare without DSH dynamic tools and guidance. The default mode is enhanced.
The host identifies itself as DSH and does not advertise unimplemented Desktop
attestation or MCP App HTML rendering. Dependency discovery reports existing paths.

The bundled runtime remains @openai/[email protected]; Desktop's experimental binary
is not redistributed or required. This is not complete Desktop parity. Known
limitations include occasional empty native command-event output even when the
model received the error, and a macOS locale issue affecting tools such as
shasum. These have not been declared fixed. To roll back, stop DSH, reinstall
[email protected], restore any changed profile configuration, and restart.

GitHub development build

Install the current main branch when testing an unreleased change:

npx @deepseek-ai/[email protected] plugin --profile web add github:yangbobo2021/relay-dsh-plugin-codex#main

main can change at any time. For a reproducible GitHub install, pin a Tag or
full Commit SHA instead. For example:

npx @deepseek-ai/[email protected] plugin --profile web add github:yangbobo2021/relay-dsh-plugin-codex#v0.2.3-rc.2

The official DSH CLI initializes the web Profile if it does not exist, asks
pnpm to install the selected package, and adds the plugin's bundle layer. No
Relay checkout is required. If you already installed the dsh command, replace
the npx @deepseek-ai/[email protected] prefix with dsh in any preview command above.

3. Start or restart DSH Web

npx @deepseek-ai/[email protected] web

If you use an installed command, run dsh web instead. Bundle membership is read
at startup, so restarting after installation, update, or removal is required.

4. Start a Codex conversation

1. Open the DSH URL printed in the terminal. The default is
   http://127.0.0.1:3080.
2. On first launch, read the DSH testing notice and select Continue.
3. Select Add workspace in the left sidebar and choose the project directory
   Codex may work in.
4. Select New Session.
5. Open the mode menu labeled Standard mode and choose Codex.
6. Enter a message and send it. Choose the backend before the first message;
   existing sessions keep the backend with which they were created.

There is no separate activation command. A successful install plus a DSH restart
activates the bundle and registers the managed Codex mode automatically.

5. Import existing Codex sessions for a Workspace

1. Select the compact Codex import icon below the Workspace list and above Settings.
2. In the dialog, confirm or change the visible Target Workspace, then select
   Scan sessions. The current Session owner or recent Workspace is only the
   initial selection; scanning never starts before this confirmation.
3. Review each eligible Codex Thread's full ID, title, source path, last activity,
   and ready or recoverable status. Select one, several, or all Threads.
4. Select Import selected.
5. Confirm that imported rows already show their Codex titles and source activity
   order, then open any Session and continue chatting.

Only eligible Threads from the explicitly selected Workspace are shown. Already-bound
Threads and Threads from another Workspace cannot be selected. Titles and recency
are available before a Session is opened; batch execution time does not replace
the Codex inventory thread/list.updatedAt order.
Codex App Server remains authoritative for model context, tool state, and
compaction. DSH stores native user/assistant presentation history and the durable
one-to-one binding; it does not copy private Codex runtime records. Each time an
imported Session is opened, the plugin reads that Codex Thread once and appends
any missing terminal user/assistant Turns to DSH's presentation history, including
interrupted or failed Turns with visible messages. Only an inProgress Turn waits for
the next open. It does
not poll in the background, synchronize while the Session stays open, or add a
manual refresh action.

What Works

• One persistent Codex App Server Thread per DSH Session
• Model and reasoning-effort selection
• Streaming answers and reasoning in the native DSH conversation
• Live output from long-running Codex shell commands in newly created Sessions, retained in DSH history
• DSH approval and user-question flows
• Images, interruption, and continuation
• Generic DSH tools exposed under the Codex App Server dsh namespace
• Optional terminal transport when the separate Relay terminal plugin is present

Tools execute through the owning Agent's DSH tool runtime and remain subject to
DSH permissions and Codex approval behavior.

Reliability and App Server Lifecycle

The DSH Host plugin owns the Codex App Server process. It starts one child while
the plugin activates, before Codex model discovery, and stops it when DSH or the
plugin shuts down. The default child comes from the pinned @openai/codex
dependency, so a global codex command is not required.

Open Settings → Advanced to see whether Codex is Connected, Not
started, Starting, Connection failed, or Codex unavailable. A
forked Session that inherited Codex history without a safe one-to-one binding
shows Rebind required in its Session header. Installation and connection
errors include a stable error code and a next action; raw errors such as spawn codex ENOENT are not shown as the user instruction.

On a blank New Session, switching among Standard, Codex, and Claude selects the
matching backend's model group and default reasoning effort. Delayed Codex model
discovery is retried, and an older asynchronous result cannot overwrite a newer
backend choice.

Forks use the Codex App Server thread/fork method. The child DSH Session sends
the inherited parent Thread id and completed lastTurnId; the returned child
Thread gets a new durable one-to-one binding. The operation fails closed if
provenance is incomplete, the source Thread has no owning DSH Session, or App
Server rejects the fork: Relay never falls back to thread/start. Existing
persisted bindings are also retained when resume fails. A pending approval is
answered only if its DSH Session, Codex Thread, Turn, Item, request, and binding
generation still match after reconnect; otherwise it is rejected with
diagnostic provenance.

See the reliability specification and
executable acceptance matrix. Approval and
structured-question composition is defined by the
DSH interaction bridge specification.

Plugin Boundary and Relay

This repository was designed and compatibility-tested in
Relay, an open-source project for
long-running agent work, external-event delivery, reusable DSH workbench views,
and multiple conversation backends.

The plugin is independently installable. Its only Relay package dependency is
the provider-neutral session import hub, which the package manager installs
automatically. It has no runtime dependency on the Relay application, Relay
Events, or another feature plugin. It does not replace the official DSH layout
or install Files and Terminal views. This separation lets a user install only
Codex while the broader Relay project can compose Codex, Claude, events, waits,
monitors, and workbench extensions when those capabilities are needed.

Explore or star Relay to follow that broader work:
https://github.com/yangbobo2021/Relay.

Update, Inspect, or Remove

Stop DSH Web before changing the bundle, then restart it afterward.

# Show why the plugin is installed
dsh plugin --profile web why relay-dsh-plugin-codex

# Update the npm dependency
dsh plugin --profile web update relay-dsh-plugin-codex

# Remove it
dsh plugin --profile web remove relay-dsh-plugin-codex

Use the npx @deepseek-ai/[email protected] prefix instead of dsh when you do not
have a persistent DSH command.

Troubleshooting

Codex is missing from the mode menu

Restart DSH Web. Then run dsh plugin --profile web why relay-dsh-plugin-codex. If pnpm cannot find the package, repeat the npm
installation command and read its final error.

The first message reports an authentication or executable error

Run codex login with an official Codex client under the same operating-system
user that starts DSH, then restart DSH. The plugin normally uses its bundled
official @openai/codex runtime and does not depend on PATH.

If the error says the bundled runtime is missing, update or reinstall the plugin
so the package manager restores the platform-specific optional dependency. A
managed deployment can explicitly select another native Codex executable:

# macOS or Linux
RELAY_CODEX_COMMAND=/absolute/path/to/codex dsh web

# Windows PowerShell
$env:RELAY_CODEX_COMMAND = 'C:\absolute\path\to\codex.exe'
dsh web

The DSH bundle configuration property codexCommand has higher priority than
RELAY_CODEX_COMMAND. Prefer an absolute native executable path; leaving both
unset selects the bundled, plugin-tested Codex version.

If Settings shows CODEX_EXECUTABLE_NOT_FOUND, remove an invalid
codexCommand/RELAY_CODEX_COMMAND override or replace it with an absolute
path. CODEX_RUNTIME_MISSING means the platform optional dependency must be
restored by reinstalling the plugin. Connection failed instead means the
executable was found but App Server initialization or its process failed.

A forked Session says Rebind required

Normal forks call App Server thread/fork and bind the returned child Thread.
This status means the source Thread/Turn could not authorize or complete that
operation—for example, the Turn was still running, provenance was incomplete,
or the source binding no longer existed. Return to the original DSH Session,
fix the reported condition, and retry Fork. The plugin intentionally does not
fall back to a fresh replacement Thread.

The composer is disabled

DSH requires a workspace before starting a coding conversation. Select Add
workspace, choose a directory, and return to New Session.

An imported Session says the Codex thread is open in another client

Codex permits only one App Server writer for a Thread. Switching to another Thread
in Codex Desktop may leave the writer held by that App Server process. Fully quit or
restart the owning Codex app, CLI, or App Server process, then retry the message in
DSH. The plugin keeps the original one-to-one binding and never creates a replacement
Thread. There is no safe force-takeover operation in the App Server protocol. Opening
the Session can still synchronize terminal presentation history through
thread/read; only continuation is blocked by writer ownership.

Installation says pnpm is missing

Install pnpm using its official installation guide
and confirm pnpm --version works in the same terminal.

DSH changed and the plugin no longer starts

DSH is a developer preview. Include the output of dsh --version, the plugin
source revision, and the startup error in a
GitHub issue.

Development

git clone https://github.com/yangbobo2021/relay-dsh-plugin-codex.git
cd relay-dsh-plugin-codex
npm install
DSH_ROOT=/path/to/deepseek-harness npm run verify
npm pack

npm run verify runs type checking, tests, and the production build. Boundary
tests reject accidental runtime dependencies on Relay or another feature plugin.

Feedback

Report bugs and feature requests in this repository's
issue tracker.

Published stable installation

Stable 0.2.2 targets DSH 0.1.1-rc.2 and the 0.1.2 preview line through 0.1.2-rc.1; install it from npm latest or Git tag v0.2.2.

npx @deepseek-ai/[email protected] plugin --profile web add relay-dsh-plugin-codex@next
# Git tag alternative, after publication:
npx @deepseek-ai/[email protected] plugin --profile web add github:yangbobo2021/relay-dsh-plugin-codex#v0.2.2