
Description
Set up and manage phone numbers in Vapi for inbound and outbound voice AI calls. Use when importing Twilio, Vonage, or Telnyx numbers, buying Vapi numbers, or configuring phone numbers for assistants.
SKILL.md
Vapi Phone Number Setup
Import phone numbers from Twilio, Vonage, or Telnyx, or use Vapi's built-in numbers to connect voice assistants to real phone calls.
Setup: Ensure
VAPI_API_KEYis set. See thesetup-api-keyskill if needed.
Quick Start — Buy a Vapi Number
Vapi provides free phone numbers for testing with daily call limits.
curl -X POST https://api.vapi.ai/phone-number \
-H "Authorization: Bearer $VAPI_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"provider": "vapi",
"assistantId": "your-assistant-id",
"name": "Main Support Line"
}'
Import from Twilio
curl -X POST https://api.vapi.ai/phone-number \
-H "Authorization: Bearer $VAPI_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"provider": "twilio",
"number": "+11234567890",
"twilioAccountSid": "your-twilio-account-sid",
"twilioAuthToken": "your-twilio-auth-token",
"assistantId": "your-assistant-id",
"name": "Twilio Support Line"
}'
Import from Vonage
curl -X POST https://api.vapi.ai/phone-number \
-H "Authorization: Bearer $VAPI_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"provider": "vonage",
"number": "+11234567890",
"credentialId": "your-vonage-credential-id",
"assistantId": "your-assistant-id",
"name": "Vonage Support Line"
}'
Import from Telnyx
curl -X POST https://api.vapi.ai/phone-number \
-H "Authorization: Bearer $VAPI_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"provider": "telnyx",
"number": "+11234567890",
"credentialId": "your-telnyx-credential-id",
"assistantId": "your-assistant-id",
"name": "Telnyx Support Line"
}'
Assign an Assistant
Every phone number can be linked to an assistant or squad for inbound calls:
curl -X PATCH https://api.vapi.ai/phone-number/{id} \
-H "Authorization: Bearer $VAPI_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"assistantId": "your-assistant-id"
}'
Or assign a squad:
curl -X PATCH https://api.vapi.ai/phone-number/{id} \
-H "Authorization: Bearer $VAPI_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"squadId": "your-squad-id"
}'
Phone Number Hooks
Configure automated actions when calls come in:
{
"hooks": [
{
"on": "call.ringing",
"do": [
{
"type": "say",
"exact": "Please hold while we connect you."
}
]
}
]
}
Managing Phone Numbers
# List all phone numbers
curl https://api.vapi.ai/phone-number \
-H "Authorization: Bearer $VAPI_API_KEY"
# Get a phone number
curl https://api.vapi.ai/phone-number/{id} \
-H "Authorization: Bearer $VAPI_API_KEY"
# Update a phone number
curl -X PATCH https://api.vapi.ai/phone-number/{id} \
-H "Authorization: Bearer $VAPI_API_KEY" \
-H "Content-Type: application/json" \
-d '{"name": "Updated Name"}'
# Delete a phone number
curl -X DELETE https://api.vapi.ai/phone-number/{id} \
-H "Authorization: Bearer $VAPI_API_KEY"
Inbound Call Flow
- Caller dials your Vapi phone number
- Vapi routes the call to the assigned assistant or squad
- The assistant speaks its
firstMessage - The conversation proceeds with the configured model, voice, and tools
Outbound Call Flow
- Create a call via
POST /callwithphoneNumberIdandcustomer.number - Vapi dials the customer from your phone number
- When answered, the assistant begins the conversation
Free Number Limitations
- Cannot make international calls
- Daily call limits apply
- For production use, import your own Twilio/Vonage/Telnyx numbers
References
Additional Resources
Vapi provides a documentation MCP server that gives compatible AI agents access to the Vapi knowledge base. Use its documentation search for advanced configuration, troubleshooting, SDK details, and anything beyond this skill.
Manual setup: If your agent doesn't auto-detect the config, run:
claude mcp add vapi-docs -- npx -y mcp-remote https://docs.vapi.ai/_mcp/server
See the Vapi MCP integration guide for setup instructions across supported agents.
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