Vapi Phone Calling Tool
Learn how to create a tool that uses Vapi to make a phone call and confirm or negotiate a demo time with an attendee.
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Vapi Phone Call Tool
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Updated: Jul 29, 2024
Description
Learn how to create a tool that uses Vapi to make a phone call and confirm or negotiate a demo time with an attendee.
Steps
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Vapi Phone Calling Tool
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On the tools page, click on "New".
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Next up, click on "Create Tool".
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Give it an phone emoji icon.
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Call it "Call and confirm or re-negotiate demo time".
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Video step
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Describe what the tool does, e.g. "Call attendee to confirm that they can still attend the demo time we have booked in for them. If not, re-negotiate over the phone, and book in a new time".
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After, click on "Add input".
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Add a "Long text input".
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Name the input "Availability".
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Video step
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Describe the input and it's expected format. e.g. "List of available demo times in iso format".
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Video step
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Paste in list of available demo times. This is an example of output that is produced by the "Get calendar availability tool", which you can learn how to build here: https://app.supademo.com/demo/clxjx5jw32kh0t2oeazi7xj5z
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Video step
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Call the variable used to access this input a more descriptive name, like "availability".
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Video step
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Click on "Text input".
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Call it "Phone number".
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Video step
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Write a description. In this case our phone number must have an area code, so we use the description to help the agent understand what phone number format is expected: "Phone number with area code, e.g. +61[rest of number]".
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Video step
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Change the variable name to "phone". You can give an example phone number too if you want. I chose not to.
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Click on "Text input".
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Give it the name "Demo start".
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Describe the input use and format, e.g. "Demo start date and time in iso format".
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Give an example of the format expected for the demo start time, e.g. "2024-06-24T09:00:00+10:00". This will help the agent work out how to convert a natural language time to the correct format.
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Video step
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After, click on "Text input", and add an input for:
- Name: Name.
- Description: The name of the call recipient.
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Next up, click on "Add step".
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Select the "Make Phone Call" tool step. There is also a make a phone call with Vapi step, but this one lets you use Relevance's Vapi account and number to make a call instead of setting up your own.
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Click on the "Phone Number" field, and enter "{{" to open the variable selector. Click on "phone" to pull in the phone number input variable we created earlier.
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Change the model to "GPT-4".
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Write a prompt to describe how your agent should behave over the phone call. You can use the one that I wrote as an example.
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In the assistant prompt field, you can write a call script for what you want your agent to say while on the call, and how to handle different responses. You can use a mix of direct call script quotes and meta guidance like I did. Experiment! :)
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You can reference input variables in your phone call prompt too.
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Click on the checkbox under "Wait for Finish", so the call details are returned after the call has ended, rather than as soon as the call has started.
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Click the plus button to add another tool-step.
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Select the "VapiAI - Call Details" tool step.
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In the "Call Id" field, type in "", where the variable name referenced is the same as the make a phone call tool-step variable.
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Video step
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Finally, click on "Save" to save your tool. Now it's ready for you to equip an agent with!