# Knowledge Base Retriever

The knowledge base retriever can be used to search the knowledge base and retrieve relevant information from the vector store based on the query. You can retrieve information from documents, websites, images, audios and videos uploaded to the knowledge base. Depending on your use case, you can use single or multiple retrievers.

<figure><img src="/files/9i1VoqCKiCVW7w1C5e2p" alt=""><figcaption></figcaption></figure>

Once you drop the retriever to the builder zone, you need to configure the query to retrieve relevant information. You can hardcode your query text in the query box.

<figure><img src="/files/Fz3FwNIyuJ7Uh0AdZuRJ" alt=""><figcaption></figcaption></figure>

Alternatively, you can pipe in the variable from the workflow to be used as a query. Type "**#**" in the Query box, it will show the list of available variables from the workflow builder. Users can also specify number of results to be fetched.

<figure><img src="/files/wqx9cCKjWMU9MNElykG7" alt=""><figcaption></figcaption></figure>

**These steps are applicable to all knowledge base retrievers.**&#x20;


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# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://document.unifiedstacks.com/workflow-elements/knowledge-base-retriever.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.