Search Knowledge Base

Configure a workflow step that runs a semantic, keyword, or hybrid search against an existing knowledge base and stores the results

Use Search Knowledge Base when you want a workflow step to query one of your knowledge bases and pass the matching chunks to later steps — for example, feeding retrieved context into an AI Prompt step.

Configuration

Option	Required	Description
Name	No	Label for the step in the workflow canvas.
Knowledge Base	Yes	The knowledge base to search, selected in Knowledge Base.
Search Query	Yes	The query string. This field supports workflow variables through Insert Variable.
Search Type	No	One of Hybrid, Semantic, or Keyword. Defaults to Hybrid.
Result Limit	No	Maximum number of matching chunks to return (1–20, default 5).
Score Threshold	No	Minimum relevance score required to include a result (0.0–1.0, default 0.0). A value of 0.0 returns all results up to the limit regardless of score.
When the step fails	No	Controls whether the workflow should Terminate Workflow or Continue if this step fails.

Search Type

• Hybrid — Combines vector similarity and keyword matching. Recommended for most queries.

• Semantic — Pure vector similarity search. Best for conceptual or natural-language queries.

• Keyword — Full-text keyword search. Best for exact-match or structured queries.

Result Limit

Controls how many chunks are returned. Higher limits increase context available to downstream steps but may also increase noise. The slider accepts values from 1 to 20.

Score Threshold

Filters out low-relevance results. Raise this value (toward 1.0) to return only highly confident matches. Leave it at 0.0 to return all results up to the limit.

Output

This step returns the matching chunks from the knowledge base:

[
  {
    "content": "...",
    "score": 0.87,
    "metadata": { ... }
  },
  ...
]

Reference the full result set in a later step:

{{step_2.output}}

A common pattern is to pass the output directly into an AI Prompt step as context:

Answer the following question using only the context below.

Context:
{{step_2.output}}

Question: {{start.query}}

Cost

Each run of this step costs 1 task.

Example

Add Search Knowledge Base from the Knowledge Base group in Search steps....

Set Knowledge Base to the knowledge base you want to query.

Enter the user's question in Search Query, or insert a variable from a start input: {{start.question}}.

Leave Search Type as Hybrid unless you have a specific reason to prefer pure semantic or keyword search.

Adjust Result Limit to control how many chunks are returned. Start with 5 and increase if answers seem incomplete.

Set Score Threshold to 0.5 or higher if you want to exclude low-confidence matches.

Click Run in the step header to test the search. Review the returned chunks in Output, then connect the output to an AI Prompt step to generate an answer.

Notes

• The effective search type falls back to the knowledge base's own default if the step setting is left at its default value.

• Score values are normalised to the 0–1 range. The exact meaning depends on the underlying embedding model and search backend.

• Search queries and results are logged as knowledge base search audit records for monitoring.

See also: Write to Knowledge Base, AI Prompt, Creating and Editing, Testing and Iteration, and Error Handling