Chatgpt-DSH

A DeepSeek Harness (DSH) plugin that signs in with a ChatGPT Plus or Pro account and exposes its ChatGPT models in DSH on the subscription quota. No API key needed.

The plugin package lives in chatgpt-plus-dsh/. This repository contains the package plus top-level documentation; the package directory itself ships only runtime files.

How it works

The plugin registers a chatgpt-plus provider route with DSH's llm service, so the account's ChatGPT models show up in the DSH model picker. Requests go to the ChatGPT backend used by the Codex CLI (https://chatgpt.com/backend-api), billed against the ChatGPT subscription rather than API usage.

Sign-in uses OpenAI OAuth (Authorization Code + PKCE S256) with the Codex CLI's public client. A short-lived listener on 127.0.0.1:1455 receives the redirect; if that port is busy, the settings page offers a paste-the-URL fallback. The resulting grant (access, refresh and ID tokens) is kept in DSH's credential store under chatgpt-plus/account and refreshed automatically before it expires.

Features

• Sign in / sign out with a ChatGPT Plus or Pro account from the DSH settings page.
• Account models listed from the ChatGPT backend, with periodic refresh and usage figures shown in the settings UI.
• Streaming chat completions via the Codex Responses endpoint, including tool calls and reasoning items where the model returns them.
• Background token refresh plus single-flight refresh shared across concurrent requests and DSH processes sharing one home.
• Settings page served from DSH's own web server (same-origin JSON endpoints); responses never contain token material.
• Runs alongside dsh-chatgpt-sub in one profile: provider route, credential key, HTTP prefix and data directory are all distinct.

Technology stack

• JavaScript (ES modules), Node.js >= 20.11.
• Zero runtime dependencies — lib/ imports only Node built-ins and sibling modules. The settings UI (lib/client.js) is a module-loader factory using react and @deepseek-ai/dsh-client-ui-primitives supplied by the host.
• Tests run on Node's built-in test runner, no test dependencies.
• Requires DeepSeek Harness 0.2.0-rc.2 or newer (llm.registerAdapter and credential records APIs).

Prerequisites

• Node.js 20.11 or newer (node --version).
• DeepSeek Harness 0.2.0-rc.2+.
• A ChatGPT Plus or Pro account for sign-in.

Installation

No npm install is required — the package declares no dependencies or peers.

1. Place the chatgpt-plus-dsh/ directory where DSH loads plugins from (for example a link: install, or dsh plugin add <path> — see your DSH docs for the exact command in your setup).
2. Add the bundle row to your profile so the plugin is mounted. The stock row from chatgpt-plus-dsh/cordis.patch.yml:

- insert:
    - id: chatgpt-plus
      name: 'chatgpt-plus-dsh'

3. Start DSH, open Plugins → ChatGPT Plus, and click Sign in with ChatGPT.

Optional row config keys (all may be omitted): callbackPort (OpenAI only accepts 1455 for this client), signInTimeoutMs, requestTimeoutMs, streamIdleTimeoutMs, clientVersion.

Configuration

There is no .env file. Secrets live only in DSH's credential store ($DSH_HOME/.credentials.yaml, record chatgpt-plus/account, file mode 0600); non-secret preferences and the cached model list live under $DSH_HOME/chatgpt-plus-dsh/ (directory 0700, owner-only ACL on Windows). All tunables are row config keys (see above) with defaults in chatgpt-plus-dsh/lib/constants.js (DEFAULTS).

Running locally

node --version            # needs >= 20.11
cd chatgpt-plus-dsh
node tests/run-all.mjs    # offline test suite, no network access

To exercise the plugin against a real DSH build, install the package into a DSH profile as described above and open the ChatGPT Plus settings page.

Building and testing

There is no build step. The supported check is the offline suite:

cd chatgpt-plus-dsh
node tests/run-all.mjs

It runs every tests/*.test.mjs in its own process and exits non-zero on any failure. Last verified: 93 passed, 0 failed (Node 24, Windows).

Project structure

chatgpt-plus-dsh/
  lib/
    index.js       # plugin entry: registers provider route, token lifecycle, settings endpoints
    controller.js  # sign-in flow, token refresh, preferences, usage/model fetching
    provider.js    # `chatgpt-plus` LLM adapter (Codex Responses endpoint)
    oauth.js       # PKCE helpers, token exchange/refresh, grant payload
    models.js      # model catalog fetch, quota/usage parsing
    rpc.js         # same-origin settings-page endpoints
    client.js      # settings page UI (host module-loader factory)
    store.js       # credential-store + $DSH_HOME persistence
    errors.js      # error taxonomy and user-facing messages
    util.js        # file, time and platform helpers
    constants.js   # identifiers, OAuth/backend endpoints, defaults
  tests/           # offline suite (`run-all.mjs` + `*.test.mjs`)
  locale/en.json   # plugin card title/description
  cordis.patch.yml # bundle row mounting the plugin
  package.json     # manifest (no dependencies, no peers)

verify/ (local only, not published) holds sandbox QA harnesses and screenshots.

Troubleshooting

• Plugin fails to load with a message about missing APIs: update DSH to 0.2.0-rc.2 or newer (assertHostSupport in lib/index.js names the missing API).
• Sign-in listener can't bind port 1455: another process (or a second DSH profile signing in) holds it. Use the paste-the-URL fallback the settings page shows, or free the port and retry.
• "Refresh token was rejected" / signed out unexpectedly: the grant expired or was revoked (including by signing in elsewhere, since rotation invalidates the old family). Sign in again from the settings page.
• Requests fail after the token expires though auto-refresh is off: either enable "Refresh tokens automatically" or use "Refresh token now" in Plugins → ChatGPT Plus.

License

MIT — see LICENSE.