MongoDBAtlasFullTextRetriever

Retrieves documents from the MongoDBAtlasDocumentStore by full-text search. This retriever is only compatible with the MongoDBAtlasDocumentStore.

Key Features

• Retrieves documents from MongoDB Atlas using full-text search.
• Only compatible with MongoDBAtlasDocumentStore.
• Supports single or multiple query strings.
• Configurable fuzzy matching, match criteria (any or all), synonyms, and score customization.
• Supports runtime filter overrides with configurable filter_policy (MERGE or REPLACE).
• Relies on the full_text_search_index configured in MongoDBAtlasDocumentStore.

Configuration

1. Drag the MongoDBAtlasFullTextRetriever component onto the canvas from the Component Library.
2. Click on the component to open the configuration panel.
3. On the General tab:
   1. Configure the MongoDBAtlasDocumentStore connection, including mongo_connection_string, database_name, collection_name, and full_text_search_index. Create a secret with your MongoDB connection string using MONGO_CONNECTION_STRING as the secret key. For instructions, see Create Secrets.
   2. Set top_k to control the maximum number of documents returned.
4. Go to the Advanced tab to configure filters and filter_policy.

Connections

MongoDBAtlasFullTextRetriever accepts a query string (or list of strings) through its query input. It outputs retrieved documents through its documents output.

Connect the Input component's query output to MongoDBAtlasFullTextRetriever's query input. Connect its documents output to a Ranker or directly to the pipeline output.

Source Code

To check this component's source code, open full_text_retriever.py in the Haystack Core Integrations repository.

Usage Examples

Basic Configuration

  MongoDBAtlasFullTextRetriever:
    type: haystack_integrations.components.retrievers.mongodb_atlas.full_text_retriever.MongoDBAtlasFullTextRetriever
    init_parameters:
      top_k: 10
      filter_policy: replace
      document_store:
        type: haystack_integrations.document_stores.mongodb_atlas.document_store.MongoDBAtlasDocumentStore
        init_parameters:
          mongo_connection_string:
            type: env_var
            env_vars:
            - MONGO_CONNECTION_STRING
            strict: false
          database_name: my-db
          collection_name: my-collection
          vector_search_index: vector-search
          full_text_search_index: full-text-search
          embedding_field: embedding
          content_field: content

This is a query pipeline with MongoDBAtlasFullTextRetriever that searches for documents in the MongoDBAtlasDocumentStore.

components:
  TransformersSimilarityRanker:
    type: haystack.components.rankers.transformers_similarity.TransformersSimilarityRanker
    init_parameters:
      model: cross-encoder/ms-marco-MiniLM-L-6-v2
      device:
      token:
        type: env_var
        env_vars:
        - HF_API_TOKEN
        - HF_TOKEN
        strict: false
      top_k: 10
      query_prefix: ''
      document_prefix: ''
      meta_fields_to_embed:
      embedding_separator: \n
      scale_score: true
      calibration_factor: 1
      score_threshold:
      model_kwargs:
      tokenizer_kwargs:
      batch_size: 16

  MongoDBAtlasFullTextRetriever:
    type: haystack_integrations.components.retrievers.mongodb_atlas.full_text_retriever.MongoDBAtlasFullTextRetriever
    init_parameters:
      filters:
      top_k: 10
      filter_policy: replace
      document_store:
        type: haystack_integrations.document_stores.mongodb_atlas.document_store.MongoDBAtlasDocumentStore
        init_parameters:
          mongo_connection_string:
            type: env_var
            env_vars:
            - MONGO_CONNECTION_STRING
            strict: false
          database_name: my-db
          collection_name: my-collection
          vector_search_index: vector-search
          full_text_search_index: full-text-search
          embedding_field: embedding
          content_field: content

connections:
- sender: MongoDBAtlasFullTextRetriever.documents
  receiver: TransformersSimilarityRanker.documents

max_runs_per_component: 100

metadata: {}

inputs:
  query:
  - TransformersSimilarityRanker.query
  - MongoDBAtlasFullTextRetriever.query

outputs:
  documents: TransformersSimilarityRanker.documents

Parameters

Inputs

Parameter	Type	Description
query	Union[str, List[str]]	The query string or a list of query strings to search for. If the query contains multiple terms, Atlas Search evaluates each term separately for matches.
fuzzy	Optional[Dict[str, int]]	Enables finding strings similar to the search terms. Note that you can't use fuzzy with synonyms. Configurable options include maxEdits, prefixLength, and maxExpansions. For more details, refer to MongoDB Atlas documentation.
match_criteria	Optional[Literal['any', 'all']]	Defines how terms in the query are matched. Supported options are "any" and "all". For more details, refer to MongoDB Atlas documentation.
score	Optional[Dict[str, Dict]]	Specifies the scoring method for matching results. Supported options include boost, constant, and function. For more details, refer to MongoDB Atlas documentation.
synonyms	Optional[str]	The name of the synonym mapping definition in the index. This value cannot be an empty string. Note that you can't use synonyms with fuzzy.
filters	Optional[Dict[str, Any]]	Filters applied to the retrieved Documents. The way runtime filters are applied depends on the filter_policy configured for the retriever.
top_k	int	Maximum number of Documents to return.

Outputs

Parameter	Type	Description
documents	List[Document]	List of Documents most similar to the given query.

Init Parameters

These are the parameters you can configure in Pipeline Builder:

Parameter	Type	Default	Description
document_store	MongoDBAtlasDocumentStore		An instance of MongoDBAtlasDocumentStore.
filters	Optional[Dict[str, Any]]	None	Filters applied to the retrieved Documents. Make sure that the fields used in the filters are included in the configuration of the full_text_search_index. The configuration must be done manually in the Web UI of MongoDB Atlas.
top_k	int	10	Maximum number of Documents to return.
filter_policy	Union[str, FilterPolicy]	FilterPolicy.REPLACE	Policy to determine how filters are applied if they're configured for the component but also passed at runtime. Possible values: MERGE and REPLACE. MERGE: If both filter types target the same field, the runtime filter takes precedence. Logical filters are combined unly if they have the same operator (AND, OR). Comparison filters are combined using the default logical operator (defaults to AND).

Run Method Parameters

These are the parameters you can configure for the component's run() method. This means you can pass these parameters at query time through the API, in Playground, or when running a job. For details, see Modify Pipeline Parameters at Query Time.

Parameter	Type	Default	Description
query	Union[str, List[str]]		The query string or a list of query strings to search for. If the query contains multiple terms, Atlas Search evaluates each term separately for matches.
fuzzy	Optional[Dict[str, int]]	None	Enables finding strings similar to the search terms. Note that you can't use fuzzy with synonyms. Configurable options include maxEdits, prefixLength, and maxExpansions. For more details refer to MongoDB Atlas documentation.
match_criteria	Optional[Literal['any', 'all']]	None	Defines how terms in the query are matched. Supported options are "any" and "all". For more details refer to MongoDB Atlas documentation.
score	Optional[Dict[str, Dict]]	None	Specifies the scoring method for matching results. Supported options include boost, constant, and function. For more details refer to MongoDB Atlas documentation.
synonyms	Optional[str]	None	The name of the synonym mapping definition in the index. This value cannot be an empty string. Note that you can't use synonyms with fuzzy.
filters	Optional[Dict[str, Any]]	None	Filters applied to the retrieved Documents. The way runtime filters are applied depends on the filter_policy configured for the retriever.
top_k	int	10	Maximum number of Documents to return.