Knowledge Base Filter
Restrict Knowledge Base retrieval at runtime to specific collections, so the LLM only receives relevant context. Added in v2.4.16.
By default, when a Tool Agent or LLM Response node performs a Knowledge Base lookup, it searches across all content in your Knowledge Base. Filter overrides let you restrict that search at runtime – so the node only retrieves chunks from specific collections or documents.
Why Use Knowledge Base Filter?
If your Knowledge Base contains multiple collections covering different topics – for example, one collection for product information and another for support policies – searching all of them simultaneously can surface irrelevant chunks. The LLM receives these irrelevant chunks as context, which can cause it to give confused, off-topic, or hallucinated answers.
Knowledge Base Filter overrides solve this by telling the retrieval system: "Only search in this collection (or these documents) for this particular node."
Common use cases:
- A product enquiry flow should only retrieve from the Products collection, not the HR or legal documents
- A multilingual setup where collections contain content in different languages – only retrieve from the matching-language collection
- A kiosk profile that serves a specific branch or region – only retrieve from that branch's content
How to Set a Knowledge Base Filter
Filter overrides are configured inside individual nodes – not globally.
- Open the Tool Agent or LLM Response node in the Conversation Editor
- Locate the Filter Knowledge Base toggle in the node configuration
- Select whether you want to to include or exclude specific collection(s)
- Select the collection(s) to restrict retrieval to
When a Knowledge Base filter is active, the retrieval step ignores all other Knowledge Base content during that node's execution.
Interaction with the Tool Agent
The Tool Agent node uses Knowledge Base retrieval as one of its available "tools." When a filter override is set, it applies to every retrieval tool call made by the Tool Agent during that turn – it cannot selectively use different filters for different tool calls within the same node execution.
If you need retrieval from multiple differently-filtered collections in a single response, consider splitting the logic across multiple nodes: use a Find Records node to retrieve structured data, and a separate LLM Response node for prose retrieval from a different collection.