How do I use multi-step generations?

[GregoireGaonach]

Hello friends,

The documentation mentions multi-step generations, which can be accessed as follows:

foreach ($response->steps as $step) {
    echo "Step text: {$step->text}";
    echo "Step tokens: {$step->usage->completionTokens}";
}

I’d like to explore this feature, but I’ve only ever received empty steps, even when using reasoning models such as gemini-2.5-flash-preview-05-20 or o4-mini-2025-04-16.

Am I missing something?

[GregoireGaonach]

It’s actually possible to retrieve all the tools that were called like this (as shown in the Tools & Function Calling documentation:

foreach ($response->steps as $step) {
    if ($step->toolCalls) {
        foreach ($step->toolCalls as $toolCall) {
            echo "Tool: " . $toolCall->name . "\n";
            echo "Arguments: " . json_encode($toolCall->arguments()) . "\n";
        }
    }
}

What I was actually hoping to retrieve were the reasoning steps—like what we can see on ChatGPT—but it seems that this is not possible through the API.

[ChrisB-TL]

Just to note that we do support the thinking block for Anthropic extended thinking - if you aren't tied to a specific provider/model: https://prismphp.com/providers/anthropic.html#extended-thinking

[GregoireGaonach]

Thanks, that's really interesting!