How to change model between multiple steps?

[sailxjx]

Description

The scenario is that I hope to use the reasoning model at the beginning of the conversation, and use the normal model in the subsequent steps to achieve a balance between performance and efficiency. This approach does not seem to be supported currently.

const response = await streamText({
        model: customModel(this.modelIdentifier),
        maxSteps: 21,
        onStepFinish: () => {
// Change model
}
})

AI SDK Version

No response

[wengxiaoxiong]

I suggest making reasoning a separate tool.
Right from the start, use the reasoning tool (with the experimental_activetool feature) to reason about the user's query, and then proceed as normal.

我建议将reasoning单独作为一个工具，上来就将用户的query使用reasoning工具（使用activetool功能）来推理，然后后续就该咋样咋样

但是ui的话就难整了，现在没有streamtool！

[lgrammel]

In AI SDK 5 you can use prepareStep to switch the model.