DeepSeek Harness — OpenAI Codex Plugin
Use your ChatGPT Plus/Pro subscription as an LLM provider in the DeepSeek Harness.
This plugin adds device-code OAuth login through both the Web settings UI and /codex CLI command — no browser callback server or localhost listener. After login, Codex models appear alongside your other providers in the DSH model selector, the access token refreshes automatically without a restart, and a Codex limits popup above Settings shows the 5-hour and weekly balance.
How it works
1. In the Web app, open Settings → OpenAI Codex → Sign in. The page opens OpenAI, shows the one-time code, and updates automatically after approval. Headless/TUI users can run /codex login for the same device-code flow. 2. The plugin stores the token triple {access, refresh, expires} in $DSH_HOME/openai-codex.json and publishes only the live access token to the DSH credential seam under OPENAI_CODEX_TOKEN. 3. Your settings.yaml maps that credential to the openai-codex route, and dsh-llm-pi-ai uses the built-in openai-codex-responses API to serve all Codex models. 4. The plugin refreshes the token automatically ~5 minutes before expiry. 5. In Web, Codex limits calls OpenAI from the server and returns only normalized usage percentages, reset times, and optional credit balances; OAuth tokens never cross into the browser.
> The limits view uses OpenAI's undocumented Codex usage endpoint, so its > response shape may change without notice.
Install
# Add the plugin to your profile (web, tui, headless, …)
dsh plugin --profile web add @syncended/dsh-codex
# Restart dsh> Note: the profile is a pnpm workspace root, so on some dsh versions the > add command needs -w: dsh plugin --profile web add -w @syncended/dsh-codex.
The plugin registers the openai-codex route defaults automatically, so no dsh settings set is needed. In Web, use Settings → OpenAI Codex. The
/codex login | status | logout commands remain available in every profile.
Like DSH's other credential settings, Web login is restricted to a loopback Web session. For a remote deployment, run /codex login on the host-facing profile instead.
Commands
| Command | Description |
|---|---|
/codex login | Start device-code OAuth login |
/codex status | Show token status and expiry |
/codex logout | Clear the stored token |
Configuration
The plugin accepts these optional config values (rarely needed):
| Key | Default | Description |
|---|---|---|
clientId | app_EMoamEEZ…hrann | OpenAI OAuth client id |
credentialRef | OPENAI_CODEX_TOKEN | Credential seam ref |
deviceCodeTimeoutSeconds | 900 (15 min) | How long the user has to approve |
refreshWindowMs | 300_000 (5 min) | Refresh this far before expiry |
tokenFile | $DSH_HOME/openai-codex.json | Override token persistence path |
Requirements
- ChatGPT Plus or Pro subscription
- DeepSeek Harness ≥ 0.1.0-rc.6
- Node.js ≥ 18
License
MIT — see [LICENSE](./LICENSE).