# ElevenLabs Knowledge Base FAQ: Files, Text, RAG, Prompts > How do you give an ElevenLabs voice agent a knowledge base? Answers on Add Files, Create Text, Prompt only vs RAG, the prompt rule and testing. Source: https://learn.ynteractive.com/content/blog/elevenlabs-knowledge-base-faq · Updated 2026-10-20 · Free from Stepthrough (https://learn.ynteractive.com) Quick answer An ElevenLabs agent's [knowledge base](https://learn.ynteractive.com/content/glossary/knowledge-base) is a set of documents it can look things up in during a call, like a binder next to the phone. You open **Knowledge Base** under **Configure**, click **Add document**, and add a file, a web page or typed text. Then you change the **System prompt** so the agent answers prices and services only from those documents, and you test it with questions that trip agents up. The [Give Your Voice Agent Knowledge lesson](https://learn.ynteractive.com/content/elevenlabs-agent-knowledge-base-price-list-faq) does this in about 9 minutes, in a practice copy that needs no account. Last updated October 20, 2026 [Take the free module →](https://learn.ynteractive.com/courses/voice-ai-jump-start/5)Module 5 of the free [Voice AI Jump Start](https://learn.ynteractive.com/courses/voice-ai-jump-start) course, about 9 minutes. No account needed. By [Robert Breen](https://learn.ynteractive.com/content/about) · Published October 20, 2026 · Updated October 20, 2026 · 5 min read ElevenLabs · Voice Agents · FAQ · Knowledge Base The example is made up. Riley, the after-hours agent for Cedar Creek Plumbing from the [first voice agent lesson](https://learn.ynteractive.com/content/elevenlabs-voice-agent-tutorial-after-hours-receptionist), can take a message but can't answer "how much is it for someone to come out tonight?" So you give it the company's price list as a PDF and a short FAQ as text. ## How do you add the documents, step by step? 1. **Open it.** In **Agents**, click **Cedar Creek After-Hours**. In the left menu, under **Configure**, click **Knowledge Base**. 2. **Upload the price list.** Click **Add document**, then **Add Files**. Click **Click or drag files to upload**, pick the PDF and click **Add File**. 3. **Check what it read.** Click the document's name and read the text ElevenLabs pulled out of it. Close it with the **X**. 4. **Add the FAQ as text.** Click **Add document**, then **Create Text**. Type *Cedar Creek FAQ* in **Text Name**, paste the FAQ into **Text Content** and click **Create Text**. 5. **Look at retrieval.** Click the **Retrieval** tab. Leave **Retrieval mode** on **Prompt only** and go back with **Sources**. 6. **Change the prompt.** On the **Agent** page, add a **Prices and services** section to the **System prompt**. 7. **Publish and test.** Click **Publish**, confirm, then **Preview** and call it with three tricky questions. Check the **Transcription** in **Conversations**. The general idea is a [knowledge base](https://learn.ynteractive.com/content/glossary/knowledge-base): approved facts the AI answers from, instead of from memory. Answering only from them is called [grounding](https://learn.ynteractive.com/content/glossary/grounding). ## What does the new prompt section say? The old [prompt](https://learn.ynteractive.com/content/glossary/prompt) told Riley to leave every price to the plumber. The new **Prices and services** section replaces that rule with four: - Answer questions about prices, services and policies only from the knowledge base: the Cedar Creek price list and the Cedar Creek FAQ. - Give a price exactly as the price list says it, including "starting at" or "plus parts". Never round, combine or estimate prices. - If a price is not in the price list, say you don't have a price for that, and the plumber will give a quote after seeing the job. Never guess. - If a caller asks about a service that is not in the knowledge base, say Cedar Creek doesn't offer it, and suggest a company that does. Documents alone are not enough. The prompt is what tells the agent to use them and to stop when the answer is not there. ## Frequently asked questions **What kinds of documents can I add?** Three kinds: a web page with **Add URL**, a file with **Add Files**, or typed text with **Create Text**. Files can be PDF, Word, TXT, [Markdown](https://learn.ynteractive.com/content/glossary/markdown), HTML or EPUB, up to 20 MB each. One document can be shared by several agents. **When should I use Create Text instead of a file?** When the content is short. The FAQ is just a few paragraphs, so the lesson types it in with **Create Text** instead of making a file. Write it the way you would brief a new receptionist: short, plain facts. **Why open the document after uploading it?** To check what ElevenLabs actually read out of it. In the lesson, every price came through as plain text, so Riley can use it. If a PDF is a scan or a picture, the text may not come through. **What should the FAQ include?** The questions callers ask and the answers you approve. Cedar Creek's covers the service area, the services it offers, the services it does not offer (heating and air conditioning, well pumps, septic pumping and gas line work), emergencies, estimates, payment, warranty and licensing. Say clearly what you don't do, so the agent can turn those calls away politely. **What is Prompt only in Retrieval mode?** With **Prompt only**, the knowledge base is never searched: documents small enough go into the prompt in full. That is right for two short documents, and it is the most reliable. **On demand** and **Every turn** search the knowledge base instead, which is for big documents like a whole product manual. **Do I need RAG?** Not for a short price list and FAQ. [RAG](https://learn.ynteractive.com/content/glossary/rag) pulls only the matching pieces of a big document into each answer. The lesson notes it adds about a quarter of a second per answer, and how much you can store depends on your ElevenLabs plan. Everything read in full adds to the LLM cost of each call, so keep small documents short. **Which test questions should I ask?** Three that trip agents up: a price that is on the list, a service you don't offer, and a price that is not on the list. In the lesson the caller asks what a visit costs tonight, whether Cedar Creek works on furnaces, and for a rough price on a whole new bathroom. Riley quotes the after-hours call-out and drain clearing straight from the list, turns the furnace down and points to an HVAC company, and declines to guess the bathroom price. **What if the agent gives only part of the price?** The lesson notes that a real test may give only the call-out price and not the drain price. That is fine as long as it is from the list. A price that is not on the list, or a rounded one, is not fine. **How do I check the answers?** In **Conversations**, open the newest call and click **Transcription**. Check every answer against the price list and the FAQ. If anything is wrong or made up, fix the document or the prompt, publish, and test again. **What do I do when prices change?** Update the price list in the knowledge base first, then publish and re-test with the questions callers actually ask.Try it free, step by step**Give Your Voice Agent Knowledge: A Price List and FAQ in ElevenLabs**. Upload a plumbing company's price list and FAQ to your ElevenLabs agent's knowledge base, tell it to answer only from them, and test it with three tricky questions, including a price it must not… You do every step yourself in a practice copy of ElevenLabs Agents, it checks your work as you go, and “Do it for me” finishes any step you get stuck on. Free, and nothing touches your real accounts.[Start the free lesson](https://learn.ynteractive.com/modules/elevenlabs-knowledge-base)[Or read the full step-by-step guide](https://learn.ynteractive.com/content/elevenlabs-agent-knowledge-base-price-list-faq) ## Key takeaways - Add documents under **Configure**, then **Knowledge Base**: **Add URL**, **Add Files** or **Create Text**. - Open each upload and check the text came through. - Leave **Prompt only** on for short documents. - Tell the agent in the prompt to answer only from the documents and never guess. - Test a listed price, a service you don't offer and an unlisted price. For what goes wrong, read [ElevenLabs knowledge base mistakes](https://learn.ynteractive.com/content/blog/elevenlabs-knowledge-base-mistakes). The steps are on one printable page in the [cheat sheets library](https://learn.ynteractive.com/content/cheat-sheets). Then [give Riley its documents](https://learn.ynteractive.com/modules/elevenlabs-knowledge-base). ## Free lessons in this post - [Give Your Voice Agent Knowledge: A Price List and FAQ in ElevenLabs](https://learn.ynteractive.com/content/elevenlabs-agent-knowledge-base-price-list-faq): Upload a plumbing company's price list and FAQ to your ElevenLabs agent's knowledge base, tell it to answer only from them, and test it with three tricky questions… ## Related terms Plain-English definitions, each with an example from a free lesson. [Knowledge base](https://learn.ynteractive.com/content/glossary/knowledge-base) · [Prompt](https://learn.ynteractive.com/content/glossary/prompt) · [Markdown](https://learn.ynteractive.com/content/glossary/markdown) · [Conversational AI](https://learn.ynteractive.com/content/glossary/conversational-ai) · [Prompt caching](https://learn.ynteractive.com/content/glossary/prompt-caching) · [AI latency](https://learn.ynteractive.com/content/glossary/ai-latency) · [AI red teaming](https://learn.ynteractive.com/content/glossary/red-teaming) · [Context engineering](https://learn.ynteractive.com/content/glossary/context-engineering) [The full AI glossary](https://learn.ynteractive.com/content/glossary) ## Keep reading - [ElevenLabs Knowledge Base: 8 Mistakes That Cause Bad Answers](https://learn.ynteractive.com/content/blog/elevenlabs-knowledge-base-mistakes): ElevenLabs knowledge base mistakes: an unchecked PDF, no "never guess" rule, missing services, RAG too early, testing only easy questions, stale prices. - [ElevenLabs First Voice Agent FAQ: Prompt, Voice, Preview](https://learn.ynteractive.com/content/blog/elevenlabs-first-agent-faq): Building your first ElevenLabs voice agent? Answers on Blank Agent, the system prompt, first message, picking a voice and LLM, Publish and Preview. - [How to Test and Improve a Voice AI Agent's Script](https://learn.ynteractive.com/content/blog/how-to-test-a-voice-ai-agent): How to test and improve a voice AI agent: test calls, tricky callers, reading transcripts, ElevenLabs tests and evaluation criteria, one fix at a time. [All blog posts](https://learn.ynteractive.com/content/blog) · [All free tutorials](https://learn.ynteractive.com/content)