> ## Documentation Index
> Fetch the complete documentation index at: https://docs.assistable.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Understand knowledge retrieval

> Know how linked sources support answers and when to use a separate live-data tool.

Knowledge retrieval searches the assistant's linked business sources and supplies relevant passages for an answer. It is useful for information such as policies, services, and FAQs that can be maintained as source material.

## What must be ready

A useful answer depends on three things: the source contains the information, processing has completed, and the knowledge base is assigned to the assistant. Creating a knowledge base without completing those steps does not make its content available to every assistant.

The chat retrieval path searches completed sources linked to the selected assistant. Voice uses its knowledge tool and assistant context to search the linked knowledge bases. The tool call and the final answer are separate steps, so test the actual customer channel.

## Retrieval is selective

The assistant receives relevant passages rather than the entire document collection. Large, contradictory, or poorly structured sources can make the wrong passage more likely to be selected. Keep each source focused, label dates and business locations clearly, and remove outdated policies.

A source that contains an answer may still need clearer wording or better organization. Compare the processed source with the original and test realistic variations of the question.

## Choose knowledge or a tool

| Need | Starting point |
| - | - |
| Explain a refund policy | Knowledge source |
| Answer opening hours by location | Clearly labeled knowledge source |
| Check current appointment availability | Connected calendar tool |
| Retrieve a customer's latest order | Authenticated live-data tool |
| Update a CRM record | Action tool with a verified result |

Use a custom endpoint when your application needs a separately managed data source or specialized lookup. Configure its authentication, inputs, errors, and response format through a [custom tool](/v3/guides/tools/custom-api).

## Verify a retrieval change

Ask a question that requires the revised source, confirm the answer against it, and test an out-of-scope question. Repeat after replacing or removing conflicting material. Do not rely on an earlier conversation's answer as evidence that new source processing has finished.

Follow [Add and test business knowledge](/v3/guides/knowledge/add-sources) for setup.

## Retrieval controls and test scope

| Surface | What you can control | What the result covers |
| - | - | - |
| Knowledge sources | Type, content, source name, replacement, deletion. [All formats and status values](/v3/guides/knowledge/add-sources). | The processed material available for retrieval. |
| Assistant → Knowledge Base | Add or remove assigned bases. | The selected assistant’s linked information; an unassigned base is not automatically shared with it. |
| Knowledge list → Enable voice / Disable voice | Voice availability, subject to account access. | Eligibility for the assistant’s voice knowledge configuration. |
| Knowledge Lab | Enter questions, stop generation, and copy responses. | Currently tests the first assigned knowledge base, not the full set of assigned bases. |
| Actual chat conversation | Customer question and assistant configuration. | Chat retrieval searches completed, non-deleted sources in linked bases and supplies selected passages. |
| Actual voice conversation | Spoken question and published voice knowledge configuration. | The voice tool resolves the assistant’s linked bases when assistant context is available. Verify on a real call. |

The standard source and assistant settings do not expose chunk-size, similarity-threshold, embedding-model, or result-count tuning. Knowledge Lab uses its own retrieval request; it is not a control for changing production retrieval settings. Avoid treating one Lab answer as proof that every assigned base is covered on the live channel.

For flow-backed assistants, test the flow’s actual knowledge/tool step separately. A flow node’s prompt mentioning a knowledge base does not itself configure a retrieval action.


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