How can I get the logit value corresponding to a specific string after model forward?

[CownowAn]

I loaded the reward model, and in Hugging Face, I obtained the scalar value reward using the following code:

reward = self.model(input_ids).logits[0].mean(dim=-1).sigmoid().cpu().tolist()[loc]

Here, loc is the position of a specific tag string.

How can I perform this in sglang?

[merrymercy]

Use return_logprob=True and logprob_start_len=0
see https://sgl-project.github.io/references/sampling_params.html