Please note: The algorithm descriptions in English have been automatically translated. Errors may have been introduced in this process. For the original descriptions, go to the Dutch version of the Algorithm Register.

DefGPT

DefGPT is the Ministry of Defence’s in-house alternative to well-known AI services such as ChatGPT. This service offers defence staff the opportunity to use Large Language Model (LLM) technology for a wide range of purposes, such as summarising or classifying texts, or as a tool for drafting new text or programming code.
Last change on 10th of August 2026, at 9:56 (CET) | Publication Standard 1.0
Publication category
Other algorithms
Impact assessment
DPIA
Status
In use

General information

Theme

Organisation and business operations

Begin date

2024-11

Contact information

https://www.defensie.nl/service/contact

Responsible use

Goal and impact

This algorithm has no direct impact on members of the public or businesses. The aim of the application is to help Ministry of Defence staff process and use information more quickly and securely. The tool supports day-to-day tasks, such as summarising texts, searching for information and drafting documents. In addition, the internal environment ensures that sensitive Ministry of Defence information remains protected and does not end up with public AI services.

Considerations

AI, and Large Language Models (LLMs) in particular, can make work much faster and more efficient. They assist with processing information, making decisions and utilising existing knowledge. This technology can therefore help the Ministry of Defence to prepare for its key tasks more quickly and effectively.


The introduction of DefGPT is a first step towards using this technology within the Ministry of Defence. It enables staff to work securely with an internal AI tool. This is important because sensitive Ministry of Defence information must not be shared with public services such as ChatGPT. This prevents others from gaining access to confidential information.

Human intervention

There is no automated decision-making involved. A human assesses the information generated by DefGPT.

Risk management

Chats are stored temporarily and then deleted. This data is not used to train the model.


Logging and authorisation take place within the application in accordance with standards set out in, amongst others, the Baseline for Information Security in the Public Sector (BIO). This enables the use of the application to be monitored.

Elaboration on impact assessments

DefGPT uses open-source models in accordance with government guidelines. The model has not been further trained using additional data from the Ministry of Defence.

Defence-specific, context-specific information is added via a link to internal data sources.

Impact assessment

Data Protection Impact Assessment (DPIA)

Operations

Data

DefGPT uses OpenAI’s GPT-OSS 120B as its base LLM algorithm. OpenAI does not specify the specific sources on which the model was trained.

Technical design

DefGPT runs on the Ministry of Defence’s own internal infrastructure.

As a result, a connection to the internet is not possible and sensitive information remains internal. 

The application utilises open-source LLM models. The available model is not trained further; the output is simply enriched with specific Ministry of Defence context through internal links to other systems.

The user interacts via a chat window, where they can ask a question or upload a file. The system sends the question to the language model. The model processes the text and generates a response, which is then displayed to the user in the chat window.

Link to code base

https://huggingface.co/openai/gpt-oss-120b