With the ADK, you can create a knowledge bases for your agents, either by connecting to your own ElasticSearch or Milvus instance, or by uploading your documents. Use YAML, JSON or Python files to create your knowledge bases for watsonx Orchestrate.

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Creating built-in Milvus knowledge bases

If you don’t have an existing Milvus or Elasticsearch instance to connect to, you can create a knowledge base by simply uploading your documents. These documents will be ingested into the built-in Milvus instance, which will serve as the backend for your knowledge base. The supported documents must follow these requirements:
  • Each file must have a unique name.
  • A single batch can include up to 20 files, with a total size limit of 30 MB.
  • The maximum file size for .docx, .pdf, .pptx, and .xlsx files is 25 MB.
  • The maximum file size for .csv, .html, and .txt files is 5 MB.
The embedding model can be either a model hosted on watsonx.ai or a custom model of type embedding.
Note: The embeddings_model_name field is optional. If you don’t provide it, the system uses ibm/slate-125m-english-rtrvr-v2 by default.
Example using an OpenAI embedding model: 
spec_version: v1
kind: knowledge_base 
name: knowledge_base_name
description: >
   A description of what information this knowledge base addresses
documents:
   - path: IBM_wikipedia.pdf
     url: https://url/IBM
   - path: history_of_ibm.pdf
     url: https://url/History_of_IBM
vector_index:
   embeddings_model_name: virtual-model/openai/text-embedding-3-small
Example using a watsonx.ai embedding model: 
spec_version: v1
kind: knowledge_base 
name: knowledge_base_name
description: >
   A description of what information this knowledge base addresses
documents:
   - "/file-path-1.pdf",
   - "relative-path/file-path-2.pdf"
vector_index:
   embeddings_model_name: ibm/slate-125m-english-rtrvr-v2
Once the knowledge base is created, you can check its status to see when it’s ready for use.

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Creating external knowledge bases

External knowledge bases allow you to connect your existing Milvus or Elasticsearch databases as a knowledge source for your agent. To configure a knowledge base with your external database, use the conversational_search_tool.index_config to define the connection details for your Milvus or Elasticsearch instance. Use the field_mapping in your index_config to to specify which fields from the search results are used for the title, body and optionally url of the search result

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Milvus

When connecting to a Milvus instance: Ensure the provided embedding_model_id is the one used when ingesting the documents in your index. Additionally, ensure you use the GRPC host and port from your Milvus instance Connections will fail if you use the HTTP host or port. Optionally, provide the server_cert to use a custom server certificate when connecting to a Milvus instance. 
spec_version: v1
kind: knowledge_base 
name: knowledge_base_name
description: >
   A description of what information this knowledge base addresses
prioritize_built_in_index: false
conversational_search_tool:
   index_config:
      - milvus:
         grpc_host: my.grpc-host.com
         grpc_port: "1234"
         server_cert: <custom server certificate>
         database: database-name
         collection: collection-or-alias-name
         index: index-name
         embedding_model_id: ibm/slate-125m-english-rtrvr
         filter: <filter for search>
         field_mapping:
            title: title-field
            body: text-field
            url: url-field

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ElasticSearch

For Elasticsearch, you can provide a custom query_body that will be sent as the POST body in the search request. This allows for advanced query customization.
  • If provided, the query_body must include the $QUERY token, which will be replaced by the user’s query at runtime.
  • If no custom query_body is provided, a keyword search will be used.
To further customize the ElasticSearch query, result_filter can be set to an array of ElasticSearch filters. If using both query_body and result_filter, the query_body must include the $FILTER token, which will be replaced by the result_filter array at runtime. 
spec_version: v1
kind: knowledge_base 
name: knowledge_base_name
description: >
   A description of what information this knowledge base addresses
prioritize_built_in_index: false
conversational_search_tool:
   index_config:
      - elastic_search:
         url: https://my.elasticsearch-instance.com
         index: my-index-name
         port: "1234"
         query_body: {"size":10,"query":{"bool":{"should":[{"text_expansion":{"ml.tokens":{"model_id":".elser_model_2_linux-x86_64","model_text":"$QUERY"}}}],"filter":"$FILTER"}}}
         result_filter: [{"match":{"title":"A_keyword_in_title"}},{"match":{"text":"A_keyword_in_text"}},{"match":{"id":"A_specific_ID"}}]
         field_mapping:
            title: title-field
            body: text-field
            url: url-field
For more information about ElasticSearch query body and filters customizations, see How to configure the advanced Elasticsearch settings
With custom search, you can connect your own search server, enabling out-of-the-box alternatives to the default search solutions. To set up a custom search, configure the URL and optionally the filter and metadata for your search. For example: 
spec_version: v1
kind: knowledge_base 
name: knowledge_base_name
description: >
   A description of what information this knowledge base addresses
prioritize_built_in_index: false
conversational_search_tool:
   index_config:
      - custom_search:
         url: https://my.custom-server.com
         filter: my custom filter
         metadata:
            foo: bar
Some custom search configurations require authentication. In that case, create a connection and pass it along with the knowledge base when you import it. To set up the server for your custom service, see Connecting to a content repository on a custom service.

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AstraDB

To connect to AstraDB knowledge base, in your knowledge base file, configure the api_endpoint, data_type, and embedding_mode for your AstraDB. You can also configure optional fields like port, server_cert, keyspace, collection, table, index_column, embedding_model_id, search_mode, limit, filter, and field_mapping. 
spec_version: v1
kind: knowledge_base 
name: knowledge_base_name
description: >
   A description of what information this knowledge base addresses
prioritize_built_in_index: false
conversational_search_tool:
   index_config:
      - astradb:
         api_endpoint: 'https://xxx-us-east-2.apps.astra.datastax.com'
         keyspace: default_keyspace
         data_type: collection      ## Possible values: `collection` or `table`
         collection: search_wa_docs
##       table: search_wa_docs         (Only if `data_type` is `table`)
##       index_column: 1               (Only if `data_type` is `table`)
         embedding_model_id: ibm/slate-125m-english-rtrvr
         embedding_mode: server     ## Possible values: `server` or `client`
         port: '443'
         search_mode: vector        ## Possible values: `vector` when `data_type` is `table` OR `vector`, `lexical`, and `hybrid` when `data_type` is `collection` 
         filter: '{"product_partNumber": "PS-SL-KIT"}'
         limit: 5
         field_mapping:
            title: title
            body: text
            url: some-url

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Configuring generation options

With the ADK, you can further fine-tune how your agent uses knowledge through the conversational_search_tool configuration in your knowledge base. You can apply these settings to both built-in Milvus knowledge bases and external knowledge bases. Below are the configurable options available within the conversational_search_tool section:
ParameterDescription
prompt_instructionSet this under generation. If specified, this instruction will be included in the prompt sent to the language model to guide response generation.
max_docs_passed_to_llmSet this under generation. If specified, define the maximum number of documents passed to the LLM. This field accepts values from 1 to 20.
generated_response_lengthSet this under generation to one of Concise, Moderate or Verbose. This setting adjusts the prompt to request responses of the specified length. If not set, the default is Moderate.
idk_messageSet this under generation. Defines the fallback message sent to the user when the knowledge base cannot provide an answer.
retrieval_confidence_thresholdSet this under confidence_thresholds to one of Off, Lowest, Low, High or Highest. This threshold determines the minimum confidence required that the retrieved documents answer the user’s query. If the confidence is below the threshold, the agent will return a default “I don’t know” response instead of generating a response. The default is “Low”.
response_confidence_thresholdSet this under confidence_thresholds to one of Off, Lowest, Low, High or Highest. This threshold evaluates the confidence that both the generated response and the retrieved documents answer the user’s query. If the confidence is below the threshold, the agent will return a default “I don’t know” response. The default is Low.
query_rewriteIf enabled, the user’s query is rewritten using the context of the conversation to support multi-turn interactions. This setting is enabled by default.
citations_shownSet this under citations. Use the citations_shown parameter to control how many citations appear during the interaction. Set a specific number to define the maximum citations displayed. Use 0 to hide all citations, or -1 to show every available citation. If not set, the default is -1, which means all available citations will be displayed
Note: In dynamic knowledge bases, only the max_docs_passed_to_llm and citations_shown parameters apply. All other settings are ignored.
spec_version: v1
kind: knowledge_base 
name: knowledge_base_name
description: >
   A description of what information this knowledge base addresses
documents:
   - "/file-path-1.pdf",
   - "relative-path/file-path-2.pdf"
conversational_search_tool:
   generation:
      prompt_instruction: Custom instruction
      max_docs_passed_to_llm: 10
      generated_response_length: Moderate
      idk_message: I'm sorry, I don't have enough information to answer that right now. Could you please rephrase or provide more details?
   confidence_thresholds:
      retrieval_confidence_threshold: Low
      response_confidence_threshold: Low
   query_rewrite:
      enabled: True
   citations:
      citations_shown: -1

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Configuring dynamic knowledge bases (Public preview)

This feature is currently in public preview. Functionality and behavior may change in future updates.
By default, classic knowledge base is used as a linear pipeline that retrieves information from whatever content store it is connected to. It takes the user’s input and the conversation context to create a query against that store and then generates an answer which is sent back to the agent. Enabling dynamic mode allows knowledge base to retrieve information as before, but the agent decides how to use it. The agent may generate an answer or use the retrieved information as context to complete tasks. In addition, the agent can be configured to create a query against the content store. To configure a dynamic knowledge base, update your configuration file with the following parameters in the conversational_search_tool schema:
ParameterDescription
query_sourceDefines the query source. Accepted values:
  • Agent: Enables dynamic mode. The agent provides the query.
  • SessionHistory: Uses classic mode. The knowledge base generates the query using user input and conversation context. If you don’t configure query_source, this is the default mode.
generationIn the generation schema, set the enabled parameter to false to activate dynamic mode.
Example: 
spec_version: v1
kind: knowledge_base
name: ibm_knowledge_base_dynamic_mode
description: General information about IBM and its history
documents:
 - path: IBM_wikipedia.pdf
   url: https://en.wikipedia.org/wiki/IBM
 - path: history_of_ibm.pdf
   url: https://en.wikipedia.org/wiki/History_of_IBM
conversational_search_tool:
  query_source: Agent
  generation:
    enabled: False