Retell AI API
states body parameter removal on POST /create-retell-llm
Stops workingSubscribe to Retell AI APIShare
On December 15, 2026, Retell AI API will remove support for the body parameter states on POST /create-retell-llm. Calls sending this parameter will fail after that day. Retell AI API is retiring multi-prompt agents in favor of conversation flow.
Calls it hits
POST /create-retell-llmbody parameter states
What to use instead of these calls
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, so rebuilding one as a conversation flow changes how it handles calls and requires testing.
Multi-prompt agents have no direct API equivalent: rebuilding one as a conversation flow changes how it handles calls and needs testing.
In 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.
Facts
- API
- Retell AI API
api.retellai.com - Kind
- Parameter removal
- Takes effect
- December 15, 2026
- Calls after that day
- Fail
- Source
- Announcement
- Last updated
- Verified
- , against Retell AI API's own pages
Questions
When does this change take effect?
Calls to POST /create-retell-llm, body parameter states on Retell AI API stop working on December 15, 2026.
What happens to calls after December 15, 2026?
They fail from that day.
How do I find the calls this hits in my code?
Okapi reads your repository, finds the calls this change hits and opens a pull request with the fix. It never commits to your branches: every change comes as a pull request you review.
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Is your code calling this?
Okapi finds the calls this change hits in your repo and opens the pull request with the fix before December 15, 2026.