Stop Debugging AI Decisions You Can't Reproduce

from fabra.core import FeatureStore, entity, feature
from fabra.context import context, ContextItem
from fabra.retrieval import retriever

store = FeatureStore()

@entity(store)
class User:
    user_id: str

@feature(entity=User, refresh="daily")
def user_tier(user_id: str) -> str:
    return "premium" if hash(user_id) % 2 == 0 else "free"

@retriever(index="docs", top_k=3)
async def find_docs(query: str):
    pass  # Automatic vector search

@context(store, max_tokens=4000)
async def build_prompt(user_id: str, query: str):
    tier = await store.get_feature("user_tier", user_id)
    docs = await find_docs(query)
    return [
        ContextItem(content=f"User is {tier}.", priority=0),
        ContextItem(content=str(docs), priority=1),
    ]