Files
2026-06-04 16:16:39 +00:00

128 lines
3.8 KiB
Python

import os
from typing import TypedDict, Dict, Any
import json
from langgraph import StateGraph, END
from langgraph.checkpoint.memory import MemorySaver
from langchain_openai import ChatOpenAI
# State definition
class ReflectState(TypedDict):
question: str
draft: str
critique: str
verdict: str # "ok" | "needs_revision"
round: int
max_rounds: int
# LLM configuration
def get_llm() -> ChatOpenAI:
"""Return a ChatOpenAI instance configured via environment variables.
If OLLAMA_BASE_URL is set, use Ollama; otherwise try OPENAI_API_KEY; fallback to local.
"""
ollama_url = os.getenv("OLLAMA_BASE_URL")
openai_key = os.getenv("OPENAI_API_KEY")
if ollama_url:
return ChatOpenAI(model="llama3", base_url=ollama_url, api_key="ollama")
if openai_key:
return ChatOpenAI(model="gpt-4o-mini")
return ChatOpenAI(model="gpt-4o-mini")
llm = get_llm()
# Node: draft_answer
def draft_answer(state: ReflectState) -> Dict[str, Any]:
question = state["question"]
prompt = f"Answer the following question in 5-10 sentences: {question}"
try:
response = llm.invoke(prompt)
draft = str(response)
except Exception as e:
raise RuntimeError(f"LLM draft generation failed: {e}")
return {"draft": draft, "round": 1}
# Node: reflect
def reflect(state: ReflectState) -> Dict[str, Any]:
draft = state["draft"]
prompt = (
"Critique the following draft for completeness, concreteness, and absence of filler. "
"Respond with a JSON object containing 'verdict' (values: 'ok' or 'needs_revision') "
"and 'critique' (text). Example: {\"verdict\": \"ok\", \"critique\": \"...\"}"
)
content = f"Draft: {draft}"
full_prompt = prompt + "\n" + content
try:
response = llm.invoke(full_prompt)
text = str(response)
except Exception as e:
raise RuntimeError(f"LLM reflect failed: {e}")
# Parse JSON
try:
data = json.loads(text)
verdict = data["verdict"]
critique = data["critique"]
except Exception:
# Fallback parsing: treat entire response as critique
verdict = "needs_revision"
critique = text
return {"critique": critique, "verdict": verdict}
# Node: rewrite
def rewrite(state: ReflectState) -> Dict[str, Any]:
draft = state["draft"]
critique = state["critique"]
prompt = (
"Rewrite the following draft based on the critique. "
"Keep the meaning but improve clarity and remove filler. "
"Output only the revised draft."
)
content = f"Draft: {draft}\nCritique: {critique}"
full_prompt = prompt + "\n" + content
try:
response = llm.invoke(full_prompt)
new_draft = str(response)
except Exception as e:
raise RuntimeError(f"LLM rewrite failed: {e}")
return {"draft": new_draft, "round": state["round"] + 1}
# Build graph
builder = StateGraph(ReflectState)
builder.add_node("draft_answer", draft_answer)
builder.add_node("reflect", reflect)
builder.add_node("rewrite", rewrite)
builder.set_entry_point("draft_answer")
# Transitions
builder.add_edge("draft_answer", "reflect")
builder.add_conditional_edges(
"reflect",
lambda s: END if s["verdict"] == "ok" else "rewrite" if s["round"] < s["max_rounds"] else END,
)
builder.add_edge("rewrite", "reflect")
# Compile graph
graph = builder.compile(checkpointer=MemorySaver())
# CLI
if __name__ == "__main__":
question = input("Enter your question: ")
initial_state: ReflectState = {
"question": question,
"draft": "",
"critique": "",
"verdict": "",
"round": 0,
"max_rounds": 2,
}
result = graph.invoke(initial_state)
print("\nFinal Result:\n")
print(f"Draft: {result['draft']}")
print(f"Critique: {result['critique']}")
print(f"Verdict: {result['verdict']}")