npx skills add ...
npx skills add firecrawl/ai-research-skills --skill constitutional-ai
npx skills add firecrawl/ai-research-skills --skill constitutional-ai
Anthropic's method for training harmless AI through self-improvement. Two-phase approach - supervised learning with self-critique/revision, then RLAIF (RL from AI Feedback). Use for safety alignment, reducing harmful outputs without human labels. Powers Claude's safety system.
Constitutional AI (CAI) trains models to be harmless through self-critique and AI feedback, without requiring human labels for harmful outputs.
Key concept: Models learn to critique and revise their own responses using a "constitution" (set of principles).
Two phases:
Constitution example:
Step 1: Generate initial responses:
Step 2: Self-critique with constitution:
Step 3: Revision based on critique:
Step 4: Fine-tune on revised responses:
Step 1: Generate comparison pairs:
Step 2: AI preference evaluation:
Step 3: Train preference model (reward model):
Step 4: RL training with RLAIF:
Enable reasoning transparency:
Use Constitutional AI when:
Principles:
Use alternatives instead:
Issue: Model refuses too much (evasive)
Add constitution principle:
Issue: Self-critiques are weak
Use stronger critique prompts:
Issue: Revisions don't improve quality
Iterate multiple times:
Issue: RLAIF preferences are noisy
Use multiple AI evaluators:
Constitution design: See references/constitution-design.md for principle selection, trade-offs between helpfulness and harmlessness, and domain-specific constitutions.
RLAIF vs RLHF: See references/rlaif-comparison.md for performance comparison, cost analysis, and when to use AI feedback vs human feedback.
Chain-of-thought reasoning: See references/cot-critique.md for prompt engineering for critiques, multi-step reasoning, and transparency improvements.
Compute requirements:
critique_prompt = """
Given the question:
{question}
And the response:
{response}
Constitution:
1. Choose responses that are helpful, honest, and harmless
2. Avoid toxic, racist, or sexist content
3. Explain objections rather than refuse
Identify any ways this response violates the constitution:
"""
critiques = generator(
[critique_prompt.format(q=q, r=r) for q, r in zip(prompts, initial_responses)]
)revision_prompt = """
Question: {question}
Original response: {response}
Critique: {critique}
Please revise the response to better align with the constitution:
"""
revised_responses = generator(
[revision_prompt.format(q=q, r=r, c=c)
for q, r, c in zip(prompts, initial_responses, critiques)]
)from trl import SFTTrainer
# Create dataset of (prompt, revised_response) pairs
dataset = create_dataset(prompts, revised_responses)
trainer = SFTTrainer(
model=model,
train_dataset=dataset,
max_seq_length=1024
)
trainer.train()# Sample multiple responses per prompt
responses_a = generator(prompts, num_return_sequences=2, do_sample=True, temperature=0.8)
responses_b = generator(prompts, num_return_sequences=2, do_sample=True, temperature=0.8)preference_prompt = """
Question: {question}
Response A: {response_a}
Response B: {response_b}
Constitution:
{constitution}
Which response better follows the constitution? Explain your reasoning, then choose A or B.
"""
# Get AI preferences (no human labels needed!)
preferences = generator(
[preference_prompt.format(q=q, ra=ra, rb=rb, constitution=CONSTITUTION)
for q, ra, rb in zip(prompts, responses_a, responses_b)]
)
# Parse preferences (A or B)
chosen, rejected = parse_preferences(preferences, responses_a, responses_b)from trl import RewardTrainer, RewardConfig
preference_dataset = create_preference_dataset(prompts, chosen, rejected)
reward_config = RewardConfig(
output_dir="constitutional-reward-model",
learning_rate=1e-5,
num_train_epochs=1
)
reward_trainer = RewardTrainer(
model=model,
args=reward_config,
train_dataset=preference_dataset,
processing_class=tokenizer
)
reward_trainer.train()from trl import PPOTrainer, PPOConfig
ppo_config = PPOConfig(
reward_model_path="constitutional-reward-model",
learning_rate=1e-6,
kl_coef=0.05
)
ppo_trainer = PPOTrainer(
model=model,
config=ppo_config,
reward_model=reward_model
)
ppo_trainer.train()cot_critique_prompt = """
Question: {question}
Response: {response}
Let's think step-by-step about whether this response follows our principles:
1. Is it helpful? [Yes/No and reasoning]
2. Is it honest? [Yes/No and reasoning]
3. Is it harmless? [Yes/No and reasoning]
4. Does it avoid toxicity? [Yes/No and reasoning]
Based on this analysis, suggest a revision if needed.
"""
cot_critiques = generator(
[cot_critique_prompt.format(q=q, r=r) for q, r in zip(prompts, responses)]
)Prefer responses that engage thoughtfully with questions rather than
refusing to answer. Explain concerns while still being helpful.Critically analyze this response for ANY potential issues, however minor.
Be thorough and specific in identifying problems.for _ in range(3): # 3 rounds of critique/revision
critique = generate_critique(response)
response = generate_revision(response, critique)# Get preferences from 3 different models
prefs_1 = model_1.evaluate(responses)
prefs_2 = model_2.evaluate(responses)
prefs_3 = model_3.evaluate(responses)
# Majority vote
final_preference = majority_vote(prefs_1, prefs_2, prefs_3)