Create a Knowledge Base for AI Voice Agents

Automate with AI3 min readUpdated 2026-03-14

A knowledge base gives your AI Voice Agent the information it needs to answer caller questions accurately. Without one, the agent relies only on its role description and system prompt.

Available on: Trial (1 KB), Agent Lite (1 KB), Agent Max (5 KBs), High Volume (custom). Not available on Pay-As-You-Go.

Content Types

You can combine any or all of these content types in a single knowledge base:

Web Pages

Add URLs and the agent learns from the page content.

Limit: Up to 500 URLs per knowledge base
Auto-refresh: Toggle on to automatically re-crawl pages every 24 hours so the agent always has current information
Best for: product pages, FAQ pages, pricing pages, policy pages

Plain Text

Paste text directly into the knowledge base editor.

Limit: Up to 40,000 characters
Best for: internal policies, scripts, information not published on your website

Q&A Pairs

Add specific question-and-answer pairs so the agent gives exact responses to common questions.

Limit: Up to 500 Q&A pairs
Input methods: Manual entry one at a time, or bulk upload via CSV or Excel file (max 25 MB)
Best for: FAQs with precise answers (hours, pricing, return policies, eligibility requirements)

Files

Upload documents the agent can reference.

Limit: Up to 10 files, 5 MB each
Supported formats: PDF, DOCX, PPT, XLS, PNG, and 30+ other formats
Best for: product catalogs, rate cards, compliance documents, training materials

How to Create a Knowledge Base

Go to Dashboard > AI Voice Agent.
Open the agent you want to configure, or create a new one.
Navigate to the Knowledge Base section.
Click Add Content and choose your content type (web pages, text, Q&A, or files).
Add your content and save.

The agent begins using the knowledge base immediately. You can add, edit, or remove content at any time.

Verify What the Agent Is Using

After your agent handles a call, check the transcript in JustCall AI:

Open the call transcript.
Look for the View Sources button next to AI responses.
Click it to see the exact knowledge base content the agent referenced for that response.

This lets you audit accuracy and identify gaps — if the agent gave an incomplete answer, you know which KB content to update.

Tips for Better Answers

Be specific in Q&A pairs. A question like "What are your hours?" with a precise answer works better than a vague paragraph about your business.
Keep text concise. The agent works better with clear, structured information than long narrative documents.
Use web pages for dynamic content. If your pricing or policies change frequently, link to the live page with auto-refresh enabled rather than pasting static text.
Review transcripts regularly. The View Sources feature shows exactly what the agent is drawing from — use it to find content that needs updating.