Provides guidance for performing causal interventions on PyTorch models using pyvene's declarative intervention framework. Use when conducting causal tracing, activation patching, interchange intervention training, or testing causal hypotheses about model behavior.
Provides guidance for performing causal interventions on PyTorch models using pyvene's declarative intervention framework. Use when conducting causal tracing, activation patching, interchange intervention training, or testing causal hypotheses about model behavior.
pyvene is Stanford NLP's library for performing causal interventions on PyTorch models. It provides a declarative, dict-based framework for activation patching, causal tracing, and interchange intervention training - making intervention experiments reproducible and shareable.
import pyvene as pv
from transformers import AutoModelForCausalLM, AutoTokenizer
model = AutoModelForCausalLM.from_pretrained("meta-llama/Llama-2-7b-hf")
tokenizer = AutoTokenizer.from_pretrained("meta-llama/Llama-2-7b-hf")
# Load pre-trained steering intervention
intervenable = pv.IntervenableModel.load(
"zhengxuanzenwu/intervenable_honest_llama2_chat_7B",
model=model,
)
# Generate with steering
prompt = "Is the earth flat?"
inputs = tokenizer(prompt, return_tensors="pt")
# Intervention applied during generation
outputs = intervenable.generate(
inputs,
max_new_tokens=100,
do_sample=False,
)
print(tokenizer.decode(outputs[0]))
Saving and Sharing Interventions
# Save locally
intervenable.save("./my_intervention")
# Load from local
intervenable = pv.IntervenableModel.load(
"./my_intervention",
model=model,
)
# Share on HuggingFace
intervenable.save_intervention("username/my-intervention")
# Load from HuggingFace
intervenable = pv.IntervenableModel.load(
"username/my-intervention",
model=model,
)
Common Issues & Solutions
Issue: Wrong intervention location
# WRONG: Incorrect component name
config = pv.RepresentationConfig(
component="mlp", # Not valid!
)
# RIGHT: Use exact component name
config = pv.RepresentationConfig(
component="mlp_output", # Valid
)
Issue: Dimension mismatch
# Ensure source and base have compatible shapes# For position-specific interventions:
config = pv.RepresentationConfig(
unit="pos",
max_number_of_units=1, # Intervene on single position
)
# Specify locations explicitly
intervenable(
base=base_tokens,
sources=[source_tokens],
unit_locations={"sources->base": ([[[5]]], [[[5]]])}, # Position 5
)
Issue: Memory with large models
# Use gradient checkpointing
model.gradient_checkpointing_enable()
# Or intervene on fewer components
config = pv.IntervenableConfig(
representations=[
pv.RepresentationConfig(
layer=8, # Single layer instead of all
component="block_output",
)
]
)