Use Your ChatGPT or Codex Subscription in DeepSeek Harness

A very common DSH question: “I already pay for ChatGPT — can I use that subscription inside DeepSeek Harness instead of buying API credits?” Yes, with a bridge plugin. Here’s how.

The short answer

Plugins that reuse your ChatGPT / Codex subscription inside DSH exist:

dsh-codex-connect — ChatGPT OAuth + Codex models for DSH
dsh-llm-codex-oauth — use your ChatGPT/Codex subscription via the Codex OAuth flow
dsh-codex-subscription — reuse your local Codex CLI login, no API key
dsh-codex — use your ChatGPT subscription through OpenAI’s Codex sign-in
dsh-llm-codebuddy — the WorkBuddy API route (if your company only provides WorkBuddy credits)

How it works

The bridge plugins use OpenAI’s official Codex OAuth sign-in flow — the same one OpenAI provides for third-party tools. After you sign in once:

The plugin exposes the subscription as a model provider in DSH (e.g. codex-oauth).
Select it in the model picker.
Your prompts run against the subscription’s quota instead of a separate API key.

Install example:

dsh plugin add github:franksong2702/dsh-codex-connect

Which one fits you

Situation	Plugin
Want the simplest OAuth setup	dsh-codex-connect
Already use Codex CLI locally	dsh-codex-subscription — reuses the local login
Company only provides WorkBuddy credits	dsh-llm-codebuddy
Prefer the raw Codex OAuth flow	dsh-llm-codex-oauth

Things to check

Your plan’s limits: subscription-based usage counts against your ChatGPT/Codex quota. Heavy agent loops can burn through it quickly.
Terms: these plugins use the official OAuth flow, but check OpenAI’s terms for your plan before routing production work through it.
Fallbacks: keep a standard API-key provider configured as a backup, and use model routing so simple questions go to a cheap model.

Model & Providers category — more provider bridges and model adapters.
dsh-model-router — automatic fallback and cost optimization across providers.

Bottom line

If you already pay for ChatGPT or Codex, a bridge plugin removes the need for a separate API key — dsh-codex-connect is the fastest start. Just keep an eye on subscription limits during long agent runs.

DeepSeek Harness Plugin FAQ

Can I use my ChatGPT subscription in DeepSeek Harness?

Yes. Plugins like dsh-codex-connect and dsh-llm-codex-oauth reuse your ChatGPT/Codex login (via OpenAI's OAuth flow) and expose the subscription as a model provider inside DSH — no separate API key needed.

How do I connect Codex to DeepSeek Harness?

Install a bridge plugin (e.g. dsh plugin add github:franksong2702/dsh-codex-connect), then follow the OAuth sign-in in the plugin's settings. After login, the Codex models appear in DSH's model selector.

Is using my ChatGPT subscription in DSH against the terms?

These plugins use the official Codex OAuth sign-in flow that OpenAI provides for third-party tools. Review OpenAI's terms for your plan; usage is billed against your subscription's limits.