### Answer I don't have specific documentation that recommends which external LLM (like ChatGPT, Claude, etc.) is best for helping you develop and build Retell AI agents outside of the platform. However, for the LLM that powers your agents within Retell AI, here's what the documentation covers: For Conversation Flow agents, you can configure the model choice per node, allowing dynamic LLM selection to tailor responses as needed. [(1) ]() Available model options include: - GPT-4o and GPT-4o Mini Realtime - Retell's proprietary low-latency LLM (Retell LLM) - Models with "Fast Tier" option for predictable latency and uncapped scale For development guidance, Retell recommends: - Using the Dashboard templates to see examples of effective prompts when creating a new agent [(2) ]() - Using the LLM Playground in the dashboard for prototyping and debugging agent prompts without making live calls [(1) ]() - Using Simulation Testing to run batch or single-scenario tests with synthetic conversations If you're asking which external AI assistant to use for coding help and development guidance, that falls outside Retell AI's documentation scope. Would you like a general answer on that?

​ To learn more, see the sources I considered: [[1] Platform Changelogs | Retell AI](https://www.retellai.com/changelog) [[2] Prompt Engineering Guide](https://docs.retellai.com/build/prompt-engineering-guide) ​

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

Appreciate the feedback! Feel free to ask me again with additional guidance or context.