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I will integrate openai and claude api with vapi or retell ai voice agent cold calling
Charlie Morgan
About this gig
Static chatbots can only take your business automation so far. To deliver an exceptional user experience and scale your operations, you need conversational AI agents that can think critically and interact naturally. I specialize in integrating premium OpenAI and Claude API models with cutting-edge real-time voice infrastructure like Vapi AI and Retell AI to build ultra-realistic, intelligent phone voice agents.
I do not just build basic setups that repeat robotic scripts. I architect highly intelligent conversational systems featuring advanced system prompt engineering, specific function calling, custom knowledge base routing, and live external API integrations. Whether you need an inbound customer support agent to answer technical FAQs or an outbound sales agent to qualify cold leads, I deploy stable, human-like voice infrastructure that handles data effectively
By pairing the reasoning capabilities of Claude or GPT with seamless telephony routing, your business gets a custom virtual workforce that operates around the clock. Let's build your next-generation voice agent today.
Get to know Charlie Morgan
Charlie Morgan
Business Automation Architect and Voice AI Engineer
- FromUnited Kingdom
- Member sinceSep 2026
- Avg. response time1 hour
Languages
English, Spanish, French
Welcome! I build high-performance business automations and autonomous AI agents designed to scale your operations. I specialize in engineering robust workflows using n8n and Make, allowing businesses to replace expensive Zapier setups and eliminate manual data entry.
I also integrate premium OpenAI and Claude APIs with Vapi and Retell AI to deploy ultra-realistic voice assistants for inbound and outbound calling. Need a structured pipeline? I connect GoHighLevel and ActiveCampaign via custom webhooks. Let's automate your brand today.
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FAQ
What is the difference between using OpenAI and Claude for voice agents?
OpenAI models are excellent for fast-paced, high-speed execution and specific function calls. Claude models are highly recognized for their exceptional conversational flow, premium nuance handling, and ability to stick strictly to complex business knowledge bases. 2
Do I need to pay for my own API and voice platform accounts?
Yes, you will need to set up your own active accounts with OpenAI/Anthropic and Vapi or Retell AI. I will handle the technical backend integration, programming, and system prompting directly using your developer environment keys securely.
Can the voice agent book appointments or look up live database data?
Yes, absolutely. In the Premium tier, I utilize custom function calling to connect your voice agent to automation tools like n8n or Make. This allows the AI to check calendar availability, book slots, and push user data directly into your CRM.
How realistic do the voices sound over an actual phone call?
By utilizing industry-standard voice synthesis engines like ElevenLabs through Vapi or Retell, the latency is incredibly low and the speech inflections sound remarkably human. Most callers cannot instantly tell they are speaking to an AI agent.
What specific information do you need from me to start building?
I will need secure API keys or temporary access to your voice platform dashboard, alongside a detailed document mapping out your company's business rules, customer FAQs, and the exact conversational tone you want the agent to use.
