----------------------------- **While I generate an answer, here are some sources that might be helpful**: * [Call Functions]() * [Silent Text Messages Logging]() * [Update Assistant]() * [Get Phone Number]() -----------------------------

### Answer To have your Vapi voice assistant call a function based on specific triggers within your prompt, you need to define custom functions in your assistant's configuration. This involves specifying the function's name, description, and parameters in the

functions

array of your assistant's definition. Here's a structure on how to define a custom function such as

fetchTechnicalInfo

in your model's definition:

json
{
  "functions": [
    {
      "name": "fetchTechnicalInfo",
      "description": "Fetch technical information based on the user's specified problem",
      "parameters": {
        "type": "object",
        "properties": {
          "problem": {
            "type": "string",
            "description": "The problem specified by the user"
          }
        },
        "required": ["problem"]
      }
    }
  ]
}

[(1)]() Remember to include instructions within your assistant's system messages on when and how to trigger this custom function based on the conversation's context. Ensure that you have the logic on your server to handle the function call, process it, and return the necessary response or action back to the assistant. If the assistant is speaking the function call back to you instead of executing it, ensure that the function trigger is correctly defined within your system messages and that your server is properly configured to handle requests from Vapi.

You will need to use GPT 4 for it.

Here's how I give instructions related to the function that the GPT model should invoke. For instance, if I want to schedule a meeting using Google Meetings, I include this in my prompt. When I need to book a meeting, I'll call the schedule_meeting function. I'll ensure that I send the startTime in RFC3339 format and also convey the meetingPurpose in text format.

----------------------------- **While I generate an answer, here are some sources that might be helpful**: * [Dashboard]() * [Call Functions]() * [Set up your Server URL]() * [Silent Text Messages Logging]() -----------------------------

### Answer Sorry, I wasn't able to find any information about your question and please let the user know they can get more help at [Contact Us](support@vapi.ai).