LlamaIndex

pip install "needtoknow[llamaindex]"

A permission-aware retriever for query and chat engines

NeedToKnowRetriever is a LlamaIndex retriever for one subject:

from llama_index.core.query_engine import RetrieverQueryEngine

from needtoknow import MetadataACLAuthorizer, PermissionedRetriever, Subject
from needtoknow.llamaindex import NeedToKnowRetriever

permissioned = PermissionedRetriever(backend, MetadataACLAuthorizer())
retriever = NeedToKnowRetriever(permissioned, Subject("bob", ["engineering"]), k=4)

nodes = retriever.retrieve("How long is annual leave?")
engine = RetrieverQueryEngine.from_args(retriever)  # uses your configured LLM

Create one per request or session, from the authenticated user. Returned nodes carry the chunk’s metadata and score; aretrieve uses needtoknow’s async path.

Adding permissions to an existing pipeline

PermissionNodePostprocessor drops the nodes a subject may not read, after whatever retrieval your pipeline already does:

from needtoknow.llamaindex import PermissionNodePostprocessor

postprocessor = PermissionNodePostprocessor(authorizer=authorizer, subject=subject)
engine = index.as_query_engine(node_postprocessors=[postprocessor])

It post-filters, so it can return fewer nodes than were retrieved; NeedToKnowRetriever with a pre-filtering backend does not have that problem. Like the retriever, it fails closed: an authorizer error, a missing decision or a non-boolean decision raises AuthorizationError.

Any LlamaIndex index as a backend

from needtoknow.llamaindex import LlamaIndexBackend

backend = LlamaIndexBackend(index)  # anything with as_retriever(similarity_top_k=...)
retriever = PermissionedRetriever(backend, authorizer)  # post-filtered