As we announced some days ago at #BCDAYIT, Dynamics 365 Business Central update 28.1 will allow you to deploy your own Business Central agents to production environments. But there’s a bit more that we did’nt say…
Gradually starting from this update, Copilot in Business Central will use GPT-5.3-chat as the default model (rollout of this new model is planned between May and June in all regions).
In the Agents page in Business Central, a new UI setting will then permit you to see which model your custom agents are currently using and then select your preferred model.
You will be able also to control model selection programmatically from AL (new method to do that will be soon available).
To use the new model, nothing is required from your side (agents you created will start using the new model as soon as it will be available in your tenant). Personally, I suggest to test the agent when you will see the model selector appearing, just to be sure that the agent behaviour will not change.
Stefano Demiliani 