This guide walks you through setting up both outbound and inbound SIP trunking between Amazon Chime SDK and Vapi using a Voice Connector.
This is a Voice Connector-only integration — inbound and outbound calls work with no Lambda functions or custom logic required. Vapi handles the AI assistant entirely. This approach is best for straightforward AI assistants on a phone number where no additional integration is needed.
This integration does not support passing custom SIP headers, metadata, or enriched escalation data (e.g., human transfer with SIP header context). For those use cases, use a SIP Media Application with CallAndBridge instead.
In the Amazon Chime SDK console, navigate to Voice Connectors and create a new one.
Configure the following settings:

Save the Outbound host name from the Voice Connector details — you need it when configuring the Vapi SIP trunk.
Navigate to the Termination tab of your Voice Connector and enable it.
Add Vapi’s static IP addresses to the allowed host list:


44.229.228.186/3244.238.177.138/32In the Termination tab, scroll to the calling plan section and select the countries you want to allow outbound calls to.
Still in the Termination tab, create a new credential with a username and password. Save these credentials — you need them for the Vapi SIP trunk configuration.

Navigate to the Phone numbers tab and click Assign from inventory to attach a phone number to this Voice Connector.

Select the phone number you want to assign and confirm.

If you don’t have any phone numbers in your inventory, order them from Amazon Chime SDK → Phone Number Management → Orders → Provision Phone Numbers.
Log in to your Vapi dashboard and retrieve your API key from the Organization Settings.
Use the following API call to create a SIP trunk credential. Replace the placeholders with your Chime SDK Voice Connector details:
Note the id (credential ID) from the response for the next step.
The outboundProtocol must be set to tls/srtp when encryption is enabled on the Voice Connector (the default).
For inbound calls, a caller dials your Chime SDK phone number. The Voice Connector routes the call to Vapi through its origination settings — no Lambda or SIP Media Application required:
Vapi needs to know which IP addresses are allowed to send SIP traffic to it. Since the Voice Connector originates calls from its regional signaling IPs, you must register those IPs as a BYO SIP trunk credential in Vapi.
Look up the SIP signaling subnet for your Voice Connector’s region from the Chime SDK Voice Connector network configuration docs.
Create the credential via the Vapi API:
Replace the ip and netmask with the values for your Voice Connector’s region. For example:
99.77.253.0 with netmask 243.80.16.0 with netmask 23Set outboundProtocol to tls/srtp if your Voice Connector has encryption enabled (the default), or udp if not.
Save the returned id — this is your Credential ID used in the following steps.
Register your Chime SDK phone number in Vapi, linking it to the credential and your assistant:
The number field must exactly match the E.164 phone number assigned to your Voice Connector (e.g., +18312168445). Inbound calls will fail to route if the numbers don’t match.
Navigate to your Voice Connector’s Origination tab and set Origination status to Enabled.

Click New to add an inbound route pointing to Vapi’s SIP server:
YOUR_CREDENTIAL_ID.sip.vapi.ai5061 (for encrypted connections)
Call your Chime SDK phone number from any phone. The call routes through the Voice Connector’s origination settings to sip.vapi.ai, where your Vapi assistant answers.
To debug issues, enable SIP logging on the Voice Connector (under the Logging tab) for detailed SIP message traces.
Now that you have Amazon Chime SDK SIP trunking configured: