# states on POST /create-retell-llm stops working

Calls to POST /create-retell-llm, body parameter states on Retell AI API stop working on December 15, 2026.

- API: Retell AI API (api.retellai.com)
- Kind: Endpoint removal
- Takes effect: December 15, 2026
- Calls after that day: fail
- Calls it hits: `POST /create-retell-llm`, `body parameter states`
- Source: [Announcement](https://docs.retellai.com/deprecation-notice/2026/12-15_multi_prompt_agents)
- Page: https://www.okapi.bot/providers/retell-ai-api/breaking-changes/states-on-post-create-retell-llm-stops-working/

## What to use instead

Build the agent as a conversation flow with POST /create-conversation-flow instead of a multi-prompt Retell LLM.

Multi-prompt agents have no direct API equivalent: rebuilding one as a conversation flow changes how it handles calls and needs testing.

## Retell AI API's words

> Retell is retiring multi-prompt agents in favor of conversation flow. New multi-prompt creation ends on 12/15/2026, and editing ends on 02/01/2027.