Build a Natural Language IVR with Telnyx Call Control and AI Inference

Nobody likes phone trees. "Press 1 for billing, press 2 for support." Miss an option? Start over. It is friction at its worst. The voice-ivr-with-agent-backend example replaces that with a natural language conversation. Callers just say what they need, and the app routes them to the right department. Code: https://github.com/team-telnyx/telnyx-code-examples/tree/main/voice-ivr-with-agent-backend What it builds A Python/Flask app that handles inbound calls with a conversational IVR: Inbound Call -> answer with Call Control -> look up menu config from KV -> LLM generates a dynamic greeting -> gather(speech) — caller says what they need -> LLM routes intent to a department -> transfer call The core primitives The app combines four Telnyx primitives: Call Control : answer() , speak() , gather_using_speech() , transfer() AI Inference : telnyx.ai.openai.chat.completions.create() for greetings and intent routing KV store : menu config per phone number (business name, departments, transfer numbers, keywords) Agent state machine : an IVRAgent class that tracks call state, turn count, and retry logic Dynamic greeting via LLM Instead of a hardcoded "Press 1 for billing," the app generates a conversational greeting from the KV config: def generate_dynamic_menu_prompt ( menu_config : dict ) -> str : departments = menu_config . get ( " departments " , []) dept_list = " \n " . join ( f " - { d [ ' name ' ] } : { d [ ' description ' ] } " for d in departments ) return ( f " You are an IVR assistant for { menu_config [ ' business_name ' ] } . " f " Available departments: \n { dept_list } \n\n " f " Greet the caller briefly and ask how you can help. " f " Keep it conversational and under 2 sentences. " ) The LLM generates the greeting through the OpenAI-compatible Telnyx Inference binding. If it fails, the app falls back to a static greeting from the KV config. Intent routing via LLM When the caller speaks, the transcription is passed to route_intent_with_llm . The LLM is instructed