Dynamics 365 Business Central: new model choice in Agent definition.
Business Central 28.1 introduces GPT-5.3-chat as the default AI model for Agents and Managed AI service, with a new UI switcher and AL methods allowing administrators to select between available models or use Auto mode. The post discusses model selection guidance and suggests Microsoft consider supporting GPT-5.5-chat for improved accuracy and hallucination reduction.
post Stefano Demiliani
"GTP-5.3-chat is now the default AI model used by Microsoft on Agents and Managed AI service."
Key points
- GPT-5.3-chat is now the default model for Agents and Managed AI service in version 28.1, with a new model switcher on the Agents page
- Available AI models can be selected via UI or programmatically through new Agent codeunit methods: SetModelId, SetModelIdToAuto, GetModelId, and GetModelName
- GPT-5.3-chat suits conversational and brainstorming tasks, while GPT-4.1-latest is better for complex data parsing and heavy workloads with large reference documentation
- GPT-5.5-chat is recommended as a future option due to 52.5% fewer hallucinations and faster response times compared to GPT-5.3-chat
Quotes
- “GTP-5.3-chat is now the default AI model used by Microsoft on Agents and Managed AI service.” (Establishes the key change in version 28.1 that affects how agents operate by default)
- “The new switcher permits you to choose the model that the agent will uses to complete tasks.” (Describes the main feature allowing administrators to configure model selection for agents)
- “You should use GPT-5.3-chat for every task that requires conversation, brainstorming and tasks where you want a natural human-like interaction.” (Provides practical guidance on when to use each model based on task requirements)
AL objects mentioned
As named in the post. A name that matches one object page by exact type and name links to it; the others stay as named.
Context
- Features: AI model switcher for Agents, SetModelId method, SetModelIdToAuto method, GetModelId method, GetModelName method, Auto model mode, GPT-5.3-chat default model, GPT-4.1-latest support
- Versions: 28.1
Source: Stefano Demiliani, community blog. Summary, key points and quotes are derived (CONTENT-NOTICE.md); read the original for the full text.