I Built a No-Code Voice AI Agent with GPT-5 & n8n (FREE Template)

AI WorkshopAbout 5 min readAug 16, 2025Watch original
THE SUMMARYAI-generated

Key Concepts:

  • Voice AI Agent: An automated system that interacts with users through voice.
  • GPT-5: An advanced language model used for creating voice AI agents.
  • Retail AI: A no-code platform for building voice AI agent frontends.
  • NAN (n8n): A workflow automation tool used as a backend for voice AI agents.
  • Prompt Engineering: Crafting instructions for the AI agent to guide its behavior.
  • Webhooks: Automated messages sent from one application to another when something happens.
  • Functions: Predefined actions that the AI agent can perform, like ending a call.
  • API (Application Programming Interface): A set of rules that allow different applications to communicate with each other.

1. Building the Voice AI Agent Frontend with Retail AI

  • Introduction to Retail AI: Retail AI is presented as a leading no-code platform for creating voice AI agents. The video encourages viewers to visit retailai.com to explore its features and comparisons with other platforms.
  • Account Creation and Free Credits: New users can create a free account on Retail AI and receive $10 in free credits to experiment with the platform.
  • Creating a Single Prompt Agent: The video demonstrates how to create a basic voice AI agent by selecting the "single prompt agent" option and starting from a blank template.
  • Universal Prompt: The left-hand side of the Retail AI interface contains the universal prompt, which provides the agent with instructions on how to interact with customers.

2. Prompt Engineering for Healthcare Check-in

  • Accessing the Prompt: A pre-built prompt for a healthcare check-in voice agent is provided for free in the AI Workshop Light community (link in description).
  • Prompt Structure: The prompt defines the agent's identity (Kate from Retail Health), style guidelines, and step-by-step instructions for interacting with customers.
  • Example Instructions: The prompt instructs the agent to introduce itself, state the purpose of the call (annual checkup reminder), and follow specific steps without skipping any.
  • Dynamic Variables: The prompt can be customized to include dynamic variables (e.g., customer name) that are populated from the NAN backend.

3. Setting up the NAN Backend

  • NAN Overview: NAN is used as the backend to retrieve customer data and trigger phone calls via Retail AI.
  • Importing the Blueprint: A pre-built NAN blueprint for the healthcare check-in agent is available for download in the AI Workshop Light community.
  • Google Sheets Integration: The NAN workflow retrieves customer information (name, phone number, appointment details) from a Google Sheet.
  • HTTP Request Node: An HTTP request node is used to send a request to Retail AI's API to initiate a phone call.
  • Authentication: An API key from the Retail AI dashboard is required for authentication.
  • Body Parameters: The HTTP request body includes parameters such as the "from" number, "to" number, name, phone number, and email, which are populated from the Google Sheet data.
  • Workflow Execution: Executing the NAN workflow triggers the phone call via Retail AI.
  • Scheduling: The workflow can be scheduled to automatically remind customers of upcoming appointments.

4. Configuring Retail AI Agent Settings

  • Agent ID: The agent ID from Retail AI is used to connect the NAN backend to the specific voice AI agent.
  • GPT-5 Model Selection: The video recommends using the GPT-5 model with the "fast tier" option for optimal performance and low latency.
  • Webhooks for Data Transfer: A webhook URL from NAN is pasted into Retail AI to receive data after the call is completed.
  • End Call Function: An "end call" function is added to the agent to ensure that the call ends gracefully when the user has no further questions.

5. Testing and Demonstration

  • Testing the Agent: The Retail AI platform provides a "test agent" feature to simulate interactions with the voice AI agent.
  • Example Conversation: A sample conversation demonstrates how the agent reminds the customer of their appointment, confirms the details, and asks about any new symptoms or concerns.
  • Webhook Data: After the test call, the data (including the conversation transcript) is sent to the NAN backend via the webhook.
  • Data Processing: The data received via the webhook can be used to update a CRM, send emails, or trigger other actions.

6. Certification and Business Opportunities

  • AI Workshop Community: The AI Workshop community offers a paid course on building production-ready voice AI agents and starting an AI agency.
  • Certification: Completing the course leads to a certification as a voice AI expert, which can be used to demonstrate expertise to potential clients.
  • AI Agency Opportunities: The video highlights the growing demand for voice AI agents and the potential for individuals to start their own AI agencies.

7. Notable Quotes

  • "Voice AI agents are one of the fastest growing sectors of the AI market."
  • "Retail AI is probably the best voice AI agent platform in the market right now."

8. Technical Terms and Concepts

  • No-code: A development approach that allows users to build applications without writing code.
  • Backend: The server-side logic and data storage that supports the frontend application.
  • Frontend: The user interface of an application.
  • API Key: A unique identifier used to authenticate requests to an API.
  • HTTP Request: A method for sending data between a client and a server.
  • JSON (JavaScript Object Notation): A lightweight data-interchange format.
  • CRM (Customer Relationship Management): A system for managing customer interactions and data.

9. Logical Connections

  • The video logically connects the frontend (Retail AI) and backend (NAN) components of the voice AI agent.
  • It demonstrates how the prompt in Retail AI guides the agent's behavior, while NAN handles data retrieval and call initiation.
  • The webhook integration ensures that data is seamlessly transferred between the frontend and backend.

10. Synthesis/Conclusion

The video provides a step-by-step guide to creating a healthcare check-in voice AI agent using Retail AI and NAN. It emphasizes the importance of prompt engineering, backend automation, and data integration. The video also highlights the growing opportunities in the voice AI market and encourages viewers to explore the AI Workshop community for further learning and certification. The key takeaway is that with no-code tools and pre-built resources, individuals can quickly build and deploy sophisticated voice AI agents for various applications.

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