Knowledge Base Search Node

The Knowledge Base Search node retrieves information relevant to a search query from documents registered in a knowledge base. By passing the retrieved information to an LLM node, you can generate accurate answers grounded in your internal documents and manuals.

In this tutorial, we’ll build a workflow that answers employee questions based on an internal expense reimbursement manual.

Note

To use the Knowledge Base Search node, you need to create a knowledge base and register documents beforehand. See Knowledge Base Feature for how to create one.

This tutorial uses an expense reimbursement manual as an example. If you don’t have a document ready, you can download our sample manual (expense reimbursement, in Japanese) to try it out.

Tutorial

Add an Input Variable to the Start Node

Create a new workflow in Studio. Select the Start node and add one input variable:

• Variable name: question
• Type: Text

This will be the input field that receives the user’s question.

Add a Knowledge Base Search Node

Add a Knowledge Base Search node after the Start node and configure it as follows:

1. Knowledge Base: Select the knowledge base containing your expense reimbursement manual (you can select multiple)
2. Search Mode: Leave it on “Fast”
3. Search Query: Enter the following

{{#start.question#}}

Tip

Type / in the search query field to browse and insert variables from previous nodes or input variables.

Generate Answers with an LLM Node

Add an LLM node after the Knowledge Base Search node. Copy and paste the following into the prompt field:

You are an internal helpdesk assistant.
Answer the employee's question based on the company manual excerpts below.

Rules:
- Only answer based on what is written in the manual
- If the manual does not cover the topic, reply: "This topic is not covered in the manual. Please contact the HR department for assistance."
- When possible, mention which section of the manual the answer is based on

## Company Manual
{{#knowledgeBase-1.context#}}

## Employee's Question
{{#start.question#}}

Overall Workflow

The final workflow looks like this:

Start → Knowledge Base Search → LLM → End

Running the Workflow

Now you’re ready! Click the debug button to run the workflow.

Example questions to try:

• “How do I submit a travel expense claim?”
• “Do I need pre-approval for client entertainment expenses?”
• “What should I do if I lost a receipt?”

Additional Information

Search Modes

You can choose a search mode depending on your needs.

Mode	Description
Fast	Returns quick answers with fewer search results. This is the default setting
Custom	Allows fine-tuning of parameters like the number of results and similarity threshold

In Custom mode, the following settings are available:

• Top K: Number of documents to retrieve (1–10)
• Min Similarity: Similarity threshold for filtering results (0.0–1.0). Higher values return only more relevant results
• Search Type: Similarity search or hybrid search

Output Variables

The Knowledge Base Search node has the following output variables. You can reference them in subsequent nodes using the format {{#knowledgeBase-1.variableName#}}.

Variable	Description
context	Text containing the content of retrieved documents
sources	Metadata about source documents (file name, similarity score, etc.)
query	The actual query used for the search