app.py

import gradio as gr
import spaces
from huggingface_hub import HfApi, hf_hub_download
import torch
from transformers import AutoTokenizer, AutoModelForCausalLM, pipeline
import pyvene as pv
from utils import get_tokens, select_concepts, get_concepts_dictionary, get_response, plot_tokens_with_highlights
import os

hf_token = os.getenv("HF_TOKEN")


@spaces.GPU
def launch_app():

    @spaces.GPU
    def process_user_input(prompt, concept):
        yield "Processing..."

        # Check if prompt or concept are empty
        if not prompt or not concept:
            return f"<h3>Please provide both a prompt and a concept</h3>"

        # Convert prompt to tokens
        tokens, token_ids = get_tokens(tokenizer, prompt)

        # Get concept IDs and names
        concept_ids, concept_df = select_concepts(all_concepts, concept)
        if len(concept_ids) == 0:
            concepts_html = f"<h3>No relevant concepts found for '{concept}' in LLM thoughts dictionary. Try another concept.</h3>"
        else:
            concepts_html = f"<h3>using the following in the LLM thoughts dictionary relevant to '{concept}' ({len(concept_ids)} out of {len(all_concepts)} concepts):</h3>"
            styled_table = concept_df.style.hide(axis="index").set_properties(**{'background-color': '#f0f0f0', 'color': 'black', 'border-color': 'white'}).to_html()
            concepts_html += f'<div style="height: 200px; overflow-y: scroll;">{styled_table}</div>'

        # Get activations
        if len(concept_ids) > 0:
            acts = pv_model.forward({"input_ids": token_ids}, return_dict=True).collected_activations[0]
            vals = acts[0, :, concept_ids].sum(-1).cpu()

            # Get highlighted tokens
            highlighted_tokens_html = plot_tokens_with_highlights(tokens, vals, concept)
        else:
            highlighted_tokens_html = ""

        # Get LLM response
        response = get_response(pipe, prompt)
        response_html = f"""<h3>LLM response to your prompt:</h3>
            {response}
        """

        # Write documentation
        documentation_html = f"""<h3>How does this work?</h3>
            <ul>
            <li>The LLM model is an instruction-tuned model, <a href="https://huggingface.co/google/gemma-2-2b-it">Google gemma-2-2b-it</a>.
            <li>The LLM interpreter, <a href="https://huggingface.co/pyvene/gemma-reft-r1-2b-it-res">gemma-reft-r1-2b-it-res</a> (not from Google) is trained on the LLM model's layer 20's residual stream. The choices of layer 20 and the residual stream are arbitrary.
            <li>The LLM interpreter decomposes the layer 20 residual stream activations into a <a href="https://huggingface.co/pyvene/gemma-reft-r1-2b-it-res/raw/main/l20/metadata.jsonl">dictionary</a> of {len(all_concepts)} human-understandable concepts. This dictionary is not comprehensive; it is possible for a concept you input to not be present in this dictionary.
            <li>Each token is highlighted in terms of how much information about a given concept is carried in each token.
            <li>Do you find the results surprising? Any feedback? Any ideas on how I can make this app more useful? Please let me know! Contact: Sarah Tan.
            </ul>
        """

        # Combine HTMLs
        output_html = highlighted_tokens_html + concepts_html + "<p>&nbsp;</p>" + response_html + "<p>&nbsp;</p>" + documentation_html

        yield output_html 

    # Set model, interpreter, dictionary choices
    model_name = "google/gemma-3-270m-it" #"google/gemma-2-2b-it"
    interpreter_name = "pyvene/gemma-reft-r1-2b-it-res"
    interpreter_path = "l20/weight.pt"
    interpreter_component = "model.layers[20].output"
    dictionary_url = "https://huggingface.co/pyvene/gemma-reft-r1-2b-it-res/raw/main/l20/metadata.jsonl"

    # Interpreter class
    class Encoder(pv.CollectIntervention):
        def __init__(self, **kwargs):
            super().__init__(**kwargs, keep_last_dim=True)
            self.proj = torch.nn.Linear(
                    self.embed_dim, kwargs["latent_dim"], bias=False)
        def forward(self, base, source=None, subspaces=None):
            return torch.relu(self.proj(base))

    # Load tokenizer and model
    tokenizer = AutoTokenizer.from_pretrained(model_name, token=hf_token)
    model = AutoModelForCausalLM.from_pretrained(model_name, device_map='auto', token=hf_token).to("cuda" if torch.cuda.is_available() else "cpu")

    # Load fast model inference pipeline
    pipe = pipeline(
        task="text-generation",
        model=model_name,
        use_fast=True, 
        token=hf_token
    )

    path_to_params = hf_hub_download(
        repo_id=interpreter_name,
        filename=interpreter_path,
        force_download=False,
    )
    params = torch.load(path_to_params, map_location="cuda" if torch.cuda.is_available() else "cpu")
    encoder = Encoder(embed_dim=params.shape[0], latent_dim=params.shape[1]).to("cuda" if torch.cuda.is_available() else "cpu")
    encoder.proj.weight.data = params.float()
    pv_model = pv.IntervenableModel({
        "component": interpreter_component,
        "intervention": encoder}, model=model).to("cuda" if torch.cuda.is_available() else "cpu")

    # Load dictionary
    all_concepts = get_concepts_dictionary(dictionary_url)

    description_text = """
    ## Does an LLM Think Like You?
    Input a prompt and a concept that you think is most relevant for your prompt. See how much (if at all) the LLM uses that concept when processing your prompt.
    Examples:
    - **Prompt**: What is 2+2? **Concept**: math
    - **Prompt**: I really like anchovies on pizza but I know a lot of people don't. **Concept**: food
    """

    with gr.Blocks() as demo:
        gr.Markdown(description_text)
        with gr.Row():
            prompt_input = gr.Textbox(label="Enter a prompt", value="I really like anchovies on pizza but I know a lot of people don't.")
            concept_input = gr.Textbox(label="Enter a concept that you think is most relevant for your prompt", value="food")
        process_button = gr.Button("See if an LLM thinks like you!")
        output_html = gr.HTML()

        process_button.click(
            process_user_input,
            inputs=[prompt_input, concept_input],
            outputs=output_html
        )
    
    demo.launch(debug=True)

if __name__ == "__main__":
    launch_app()