Outbound API calls not using updated prompt

Support Help
1

Hi,

I’m experiencing an issue where outbound calls made via API always use an old version of the agent prompt, even after updating it.

Steps to reproduce:

  1. I have an agent (agent_c0cd0840fd60882f793ebb629f) with a Retell LLM (llm_cfe7c999f84e89b496b826531538)
  2. I update the prompt via the dashboard or via PATCH /update-retell-llm
  3. I trigger an outbound call via POST /v2/create-phone-call
  4. The call uses the OLD prompt, not the updated one

What I noticed:

  • Test Audio in the dashboard works correctly with the new prompt :white_check_mark:
  • Outbound API calls always use the old prompt :cross_mark:
  • The agent shows "is_published": false even after clicking Publish in the dashboard
  • base_version in the API response is different from version — it seems the published version is cached

Question: How can I force outbound API calls to use the latest version of the prompt? Is there a way to publish the agent via API?

Thank you

2

Hey @fuska70 , thanks for providing the details and the Agent ID. Let me check this with the team, and I’ll get back to you with an update as soon as possible.

3

what does your payload look like for the outbound calls?

4

Rispondi con questo:

Hi, here is the payload we use for outbound calls:

{
  "from_number": "+3901211976101",
  "to_number": "+39XXXXXXXXXX",
  "agent_id": "agent_fe6dff49276e099dd25c69ef50",
  "retell_llm_dynamic_variables": {
    "to_number": "+39XXXXXXXXXX",
    "business_name": "Nome Attività",
    "zona": "Oulx",
    "indirizzo": "Via Roma 1, Oulx",
    "tier": "HOT",
    "tpv": "€15.000",
    "note": "note qualifica"
  }
}

We have also tried adding override_agent_version: 2 and override_agent_version: 3 but the result is the same — the call always uses the old published prompt (v2.6) instead of the updated one (v2.7).

The agent shows is_published: false and base_version: 3 via the GET agent API, even after calling publish-agent-version with version 2 and 3.

The Test Audio in the dashboard works correctly with the new prompt, but outbound API calls always use the old one.

5

Hey @fuska70 Just checked with the team, the agent itself is publishing correctly. Latest published version on agent_c0cd0840fd60882f793ebb629f is v99 (isPublished: true). The actual issue is on the phone-number side has its outbound agent pinned to agent version 81, so every call from POST /v2/create-phone-call loads that old version regardless of how many times you republish.

Test Audio works because it resolves the agent’s latest published version directly, bypassing the phone-number binding.

Fix: in the dashboard, open Phone Numbers → Outbound Agent, re-select Sofia and save set the version dropdown to “Latest” so future publishes flow through automatically. Or via API: PATCH /update-phone-number/ with the outbound agent’s version set to 99 (or the version you want).

About is_published: false and base_version that’s the in-editor draft, which is expected. Drafts always carry isPublished: false and a baseVersion pointing at the version they were forked from; the published row (v99) carries isPublished: true. There isn’t currently a “publish via API” endpoint publishing is a dashboard action that creates a new version record.

Thank You