DeepSeek has added Creator Mode to DeepSeek Harness, its open-source AI agent app: you describe a plugin in the chat, and the agent writes the code, installs it and checks that it runs. Bloomberg reported the launch on 2 November. Harness is in public preview worldwide, so anyone in the Netherlands can install it today on a Mac or a Windows PC.
In DeepSeek’s demo, one sentence became a working plugin in 5 minutes 24 seconds
The Harness page shows the request “Write a Pomodoro timer plugin for me.” The agent then loads its own guide for building plugins and looks at what the app lets a plugin use. Next it writes a settings file and a JavaScript file of 638 lines. It installs the result with its plugin manager, fixes a few lines and runs a command to confirm the plugin is live. The outcome is a floating focus timer, and DeepSeek’s log puts the whole run at 5 minutes 24 seconds.
You start it by choosing Creator Mode in the chat. DeepSeek also published seven example prompts in English and Chinese, BigGo and Implicator report. They range from a 3D viewer of famous landmarks to a paper reader and a plugin that counts statistics over your own conversations. DeepSeek adds that some demo plugins took several rounds of conversation, so one prompt may not give the result in its videos. The timing is DeepSeek’s own recording, not an independent test.
Harness as DeepSeek describes it today:
- Desktop apps for macOS on Apple silicon and 64-bit Windows, plus a web version you start from the command line.
- Open source under the MIT licence; DeepSeek’s page shows no price.
- It runs on DeepSeek’s models through a DeepSeek API key, or on other providers and OpenAI-compatible endpoints.
- The GitHub page calls it a developer preview and warns of changes that break compatibility.
DeepSeek has not documented what a self-built plugin is allowed to touch
A Harness plugin is a small code module that can add tools, skills and parts of the interface. The agent around it can read and edit files in your workspace and run commands. The web version asks before actions that need approval under the active permission policy.
DeepSeek’s pages do not say whether plugins run with the same rights as the app, whether they are sandboxed, or whether anything reviews their code. For plugins from third-party markets, the documentation says Harness checks the file format, but not the author or source a market claims. It advises adding only sources you trust. There are no admin controls for organisations in the documentation.
Where does DeepSeek Harness store your data?
With DeepSeek’s own models, in China. The DeepSeek Harness privacy policy says DeepSeek collects session logs: your inputs, uploaded files, tool calls, plugin settings and conversations. It stores personal data in the People’s Republic of China and may use it to train its models. You can opt out of training by emailing DeepSeek, but the policy names no setting for it.
If you connect another model provider with your own API key, you need no DeepSeek account. The policy says Harness then does not store your inputs and outputs on its servers. It does not explain how that fits with the section on session logs, and it does not mention the GDPR or an EU data region. In early 2025 the Autoriteit Persoonsgegevens, the Dutch data protection authority, warned users about DeepSeek’s chatbot and said it would look into data transfers to China.
Keep Creator Mode on a test machine until DeepSeek documents plugin rights
Creator Mode turns every user into a software author. A colleague can build a timer, a report tool or a file converter in five minutes. That colleague has also written code that runs inside an agent that can read files and run commands. Often nobody else will know it exists. For the organisations DataNorth works with, the risk is not code that fails, because the agent checks that it runs. The risk is code that nobody reviewed, with access to company data.
So decide now which agent apps staff may install, which data they may use them on, and who looks at a self-built plugin before it touches company files. To try Creator Mode, use a separate machine or virtual machine with sample data. Connect a model provider whose data location you know, and read the code the agent writes. Keep it off work laptops until DeepSeek documents what plugins may access, adds admin controls and leaves the preview.
For more information, visit the official introduction of Creator Mode on the DeepSeek Harness page.
