Introduction

The core architecture of DeepSeek Harness (DSH) is modular. When using models or interfaces from ChatGPT Web, an API key or Secure MCP Tunnel is typically required. dsh-chatgpt-web provides an alternative that does not require these external dependencies: it leverages a local Chrome extension to take over an already logged-in ChatGPT session in the user’s browser and use it as a data source for DSH.

What It Is

This is an experimental standalone DeepSeek Harness provider, maintained by NishiMihaeru. It connects to an authenticated ChatGPT Web session through a local Chrome extension. The native DSH chat interface communicates with the extension via a local WebSocket bridge, controlling a dedicated ChatGPT Worker Tab.

Core Features

The plugin implements the following features:
* Text Provider: Provides the chatgpt-web/auto data source; currently only supports text input/output.
* Session Management: Each DSH session corresponds to a ChatGPT conversation created by the plugin and managed by the extension.
* Dedicated Tab: The extension opens a dedicated Chrome Worker Tab to handle generation requests.
* FIFO Serialization: The output of browser-generated content follows the first-in, first-out (FIFO) principle.
* Interruption Synchronization: Cancellation operations in DSH trigger ChatGPT to stop generating.
* Persistent Mapping: The mapping between DSH session IDs and ChatGPT URLs, along with synchronization summaries, is persisted.
* Recovery Mechanism: If the managed ChatGPT conversation is found to be missing before sending, a safe recovery can be performed.
* Context Awareness: Runtime context-aware response positioning prevents DSH plugin snapshots from being mistaken for user requests.
* Authentication: Validates stable Chrome extension identity and Origin on the loopback bridge.

Installation and Enablement

Installing the plugin requires DeepSeek Harness 0.1.1-rc.2 and Node.js ^22.19.0 || >=24.0.0 version requirements.

Use the official installation command:

dsh plugin --profile web add dsh-chatgpt-web

Enable the Chrome extension:
1. Open chrome://extensions.
2. Enable Developer mode.
3. Click Load unpacked extension.
4. Select the plugin’s extension directory.

Select in DSH:

chatgpt-web/auto

Then use the normal DSH chat interface.

Use Cases and Cautions

  • Environment Requirements: An external Chrome/Chromium browser is required with the unpacked extension installed.
  • Text Limitations: The current version only supports text input/output and does not support tool calls (although tool modes may be received, they cannot be executed on the ChatGPT side).
  • Parameter Limitations: reasoningEffort, temperature, maxTokens, stop, and DSH-assisted purpose calls are all rejected because ChatGPT Web does not support these parameters.
  • Output Semantics: Browser delta events are only observed as internal transport and are not sent to DSH as user-visible incremental text. Text is only emitted as a complete text block upon generation-complete, which means the v0.1 version sacrifices token-by-token streaming to ensure correctness.
  • Maintainability: Changes to the DOM of ChatGPT Web may require updating extension/chatgpt-page-adapter.js.

Summary

dsh-chatgpt-web allows developers to run DSH using their existing ChatGPT Web account without an OpenAI API Key. It achieves session reuse and interruption synchronization through a local extension bridge. However, in the v0.1 version, it is a feature-limited text-only provider and is quite sensitive to the browser environment and the DOM structure on the ChatGPT side.