Source code for langchain_aws.retrievers.bedrock

from typing import Any, Dict, List, Literal, Optional, Union

import boto3
from botocore.client import Config
from botocore.exceptions import UnknownServiceError
from langchain_core.callbacks import CallbackManagerForRetrieverRun
from langchain_core.documents import Document
from langchain_core.pydantic_v1 import BaseModel, Field, root_validator
from langchain_core.retrievers import BaseRetriever
from typing_extensions import Annotated

FilterValue = Union[Dict[str, Any], List[Any], int, float, str, bool, None]
Filter = Dict[str, FilterValue]


[docs]class SearchFilter(BaseModel): """Filter configuration for retrieval.""" andAll: Optional[List["SearchFilter"]] = None orAll: Optional[List["SearchFilter"]] = None equals: Optional[Filter] = None greaterThan: Optional[Filter] = None greaterThanOrEquals: Optional[Filter] = None in_: Optional[Filter] = Field(None, alias="in") lessThan: Optional[Filter] = None lessThanOrEquals: Optional[Filter] = None listContains: Optional[Filter] = None notEquals: Optional[Filter] = None notIn: Optional[Filter] = Field(None, alias="notIn") startsWith: Optional[Filter] = None stringContains: Optional[Filter] = None class Config: allow_population_by_field_name = True
[docs]class VectorSearchConfig(BaseModel, extra="allow"): # type: ignore[call-arg] """Configuration for vector search.""" numberOfResults: int = 4 filter: Optional[SearchFilter] = None overrideSearchType: Optional[Literal["HYBRID", "SEMANTIC"]] = None
[docs]class RetrievalConfig(BaseModel, extra="allow"): # type: ignore[call-arg] """Configuration for retrieval.""" vectorSearchConfiguration: VectorSearchConfig nextToken: Optional[str] = None
[docs]class AmazonKnowledgeBasesRetriever(BaseRetriever): """`Amazon Bedrock Knowledge Bases` retrieval. See https://aws.amazon.com/bedrock/knowledge-bases for more info. Args: knowledge_base_id: Knowledge Base ID. region_name: The aws region e.g., `us-west-2`. Fallback to AWS_DEFAULT_REGION env variable or region specified in ~/.aws/config. credentials_profile_name: The name of the profile in the ~/.aws/credentials or ~/.aws/config files, which has either access keys or role information specified. If not specified, the default credential profile or, if on an EC2 instance, credentials from IMDS will be used. client: boto3 client for bedrock agent runtime. retrieval_config: Configuration for retrieval. Example: .. code-block:: python from langchain_community.retrievers import AmazonKnowledgeBasesRetriever retriever = AmazonKnowledgeBasesRetriever( knowledge_base_id="<knowledge-base-id>", retrieval_config={ "vectorSearchConfiguration": { "numberOfResults": 4 } }, ) """ knowledge_base_id: str region_name: Optional[str] = None credentials_profile_name: Optional[str] = None endpoint_url: Optional[str] = None client: Any retrieval_config: RetrievalConfig min_score_confidence: Annotated[Optional[float], Field(ge=0.0, le=1.0)] @root_validator(pre=True) def create_client(cls, values: Dict[str, Any]) -> Dict[str, Any]: if values.get("client") is not None: return values try: if values.get("credentials_profile_name"): session = boto3.Session(profile_name=values["credentials_profile_name"]) else: # use default credentials session = boto3.Session() client_params = { "config": Config( connect_timeout=120, read_timeout=120, retries={"max_attempts": 0} ) } if values.get("region_name"): client_params["region_name"] = values["region_name"] if values.get("endpoint_url"): client_params["endpoint_url"] = values["endpoint_url"] values["client"] = session.client("bedrock-agent-runtime", **client_params) return values except ImportError: raise ModuleNotFoundError( "Could not import boto3 python package. " "Please install it with `pip install boto3`." ) except UnknownServiceError as e: raise ModuleNotFoundError( "Ensure that you have installed the latest boto3 package " "that contains the API for `bedrock-runtime-agent`." ) from e except Exception as e: raise ValueError( "Could not load credentials to authenticate with AWS client. " "Please check that credentials in the specified " "profile name are valid." ) from e def _filter_by_score_confidence(self, docs: List[Document]) -> List[Document]: """ Filter out the records that have a score confidence less than the required threshold. """ if not self.min_score_confidence: return docs filtered_docs = [ item for item in docs if ( item.metadata.get("score") is not None and item.metadata.get("score", 0.0) >= self.min_score_confidence ) ] return filtered_docs def _get_relevant_documents( self, query: str, *, run_manager: CallbackManagerForRetrieverRun, ) -> List[Document]: response = self.client.retrieve( retrievalQuery={"text": query.strip()}, knowledgeBaseId=self.knowledge_base_id, retrievalConfiguration=self.retrieval_config.dict(exclude_none=True), ) results = response["retrievalResults"] documents = [] for result in results: content = result["content"]["text"] result.pop("content") if "score" not in result: result["score"] = 0 if "metadata" in result: result["source_metadata"] = result.pop("metadata") documents.append( Document( page_content=content, metadata=result, ) ) return self._filter_by_score_confidence(docs=documents)