Choose the most appropriate model automatically

Currently, developers need to select a model on their own, and the variables involved in this choice include:

1. The capabilities of the model itself
2. The model’s context length
3. The pricing of the model (unlimited free usage, limited usage with different prices)

My suggestion:

First, Copilot should perform semantic analysis on the user’s current input prompt to determine the appropriate context. For example, if the user has started a new topic, previous context can be discarded. If the user is referring to modifying previous content or correcting errors, then the prior context should be retained.

After that, Copilot can begin to assess the difficulty of the question. For instance, is it a simple UI change or a complete UI design? Is it about fixing an error highlighted by the editor, or about correcting a logical error in a previous answer, etc.?

Finally, Copilot can choose the most cost-effective model based on the context length and the difficulty of the problem.

The reason I want this feature is that I often switch to the highest tier, like Sonnet 4 or GPT-5, and forget to switch back to GPT-4.1. This leads to unnecessary consumption of advanced requests.