### Answer Based on the available documentation, there isn't a dedicated PATCH endpoint for updating or replacing files in an existing knowledge base. However, you can achieve file replacement through a two-step process: 1. Delete the existing source using the DELETE endpoint [(1) ]() :

javascript
import Retell from 'retell-sdk';
const client = new Retell({
  apiKey: 'YOUR_RETELL_API_KEY',
}) ;
const knowledgeBaseResponse = await client.knowledgeBase.deleteSource(
  'kb_1234567890',
  'source_1234567890',
) ;
console.log(knowledgeBaseResponse.knowledge_base_id) ;

2. Add the new source using the

addSources

method [(2) ]() :

javascript
import Retell from 'retell-sdk';
const client = new Retell({
  apiKey: 'YOUR_RETELL_API_KEY',
}) ;
const knowledgeBaseResponse = await client.knowledgeBase.addSources({
  knowledge_base_files: [
    fs.createReadStream("../sample.txt") ,
  ],
}) ;
console.log(knowledgeBaseResponse.knowledge_base_id) ;

To identify which source to delete, you can use the List Knowledge Bases endpoint to retrieve

knowledge_base_sources

which includes

source_id

for each source [(3) ]() . For your recurring .csv updates, you'd need to automate this delete-then-add workflow.

​ To learn more, see the sources I considered: [[1] Delete Knowledge Base Source](https://docs.retellai.com/api-references/delete-knowledge-base-source) [[2] Major Issue with KB](https://community.retellai.com/t/major-issue-with-kb/228) [[3] List Knowledge Bases](https://docs.retellai.com/api-references/list-knowledge-bases) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.

### Answer Yes, you can update the knowledge base your agent references. The approach depends on your agent type: For Conversation Flow agents, you can update the

knowledge_base_ids

field using the Update Conversation Flow endpoint: [(1) ]()

javascript
import Retell from 'retell-sdk';
const client = new Retell({
  apiKey: 'YOUR_RETELL_API_KEY',
}) ;
const conversationFlowResponse = await client.conversationFlow.update('conversation_flow_id') ;
console.log(conversationFlowResponse.conversation_flow_id) ;

The

knowledge_base_ids

parameter accepts an array of knowledge base IDs (e.g.,

["kb_001", "kb_002"]

) . For Voice Agents and Chat Agents, the knowledge base is typically configured within the Response Engine (the attached Retell LLM) , not directly on the agent itself. [(2) ]() [(3) ]() So to answer your question: if you're using a Conversation Flow, you can directly patch it with updated

knowledge_base_ids

. If you're using a Retell LLM as your response engine, you'd update the knowledge base configuration on the LLM itself rather than the agent.

​ To learn more, see the sources I considered: [[1] Update Conversation Flow](https://docs.retellai.com/api-references/update-conversation-flow) [[2] Update Voice Agent](https://docs.retellai.com/api-references/update-agent) [[3] Update Chat Agent](https://docs.retellai.com/api-references/update-chat-agent) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.