Connect a Kenyan Number to Vapi with a BYO SIP Trunk
Use a Sautikit Kenyan number with a Vapi assistant: create a BYO SIP trunk credential, attach the number, forward inbound calls and dial out over UDP.
Use a Sautikit Kenyan number with a Vapi assistant: create a BYO SIP trunk credential, attach the number, forward inbound calls and dial out over UDP.
A Vapi assistant can answer and place calls on a Kenyan Sautikit number through Vapi's bring-your-own SIP trunk. Create a byo-sip-trunk credential in Vapi with two gateways: Sautikit's signalling IP (inbound only) and sip.sautikit.com port 5080 over UDP (outbound only, authenticated with your number's SIP username and password). Attach your number to that credential, then forward the Sautikit number to +2547XXXXXXXX@<credential-id>.sip.vapi.ai. The number costs KES 500 a month, inbound calls are free on Sautikit and outbound calls cost KES 3.00 a minute billed per second. Vapi bills its own platform minutes.
sip.sautikit.com resolves to (62.12.113.167 as of November 2026). Check it with dig +short sip.sautikit.com before you go live.Vapi needs a hostname gateway for outbound calls and a numeric IP gateway for inbound calls, so create two:
const res = await fetch("https://api.vapi.ai/credential", {
method: "POST",
headers: {
Authorization: `Bearer ${process.env.VAPI_API_KEY}`,
"Content-Type": "application/json",
},
body: JSON.stringify({
provider: "byo-sip-trunk",
name: "Sautikit Kenya",
gateways: [
{
ip: "62.12.113.167",
inboundEnabled: true,
outboundEnabled: false,
},
{
ip: "sip.sautikit.com",
port: 5080,
outboundProtocol: "udp",
inboundEnabled: false,
outboundEnabled: true,
},
],
outboundAuthenticationPlan: {
authUsername: process.env.SAUTIKIT_SIP_USERNAME,
authPassword: process.env.SAUTIKIT_SIP_PASSWORD,
},
outboundLeadingPlusEnabled: true,
}),
});
const credential = await res.json();
console.log(credential.id); // keep this: it is part of the inbound SIP addressoutboundLeadingPlusEnabled keeps the + on Kenyan numbers, because Sautikit dials E.164 destinations (+254…).
await fetch("https://api.vapi.ai/phone-number", {
method: "POST",
headers: {
Authorization: `Bearer ${process.env.VAPI_API_KEY}`,
"Content-Type": "application/json",
},
body: JSON.stringify({
provider: "byo-phone-number",
name: "Sautikit Kenya",
number: "+254709000000",
numberE164CheckEnabled: true,
credentialId: process.env.VAPI_CREDENTIAL_ID,
assistantId: process.env.VAPI_ASSISTANT_ID,
}),
});Use your own Sautikit number and the credential id from step 1. The assistantId is the assistant that answers inbound calls.
In the Sautikit console, open the number and set Forward to one destination:
+254709000000@YOUR_CREDENTIAL_ID.sip.vapi.aiNo sip: prefix. Save. Calls to your Kenyan number now reach the Vapi assistant. The same setting is forward.destinations in the API (Forward calls and voicemail).
Start a call from Vapi with the phone number id from step 2 and a customer number in E.164 format. Vapi sends the call to sip.sautikit.com:5080 with your SIP username and password, and the customer sees your Sautikit number.
Inbound calls fail with 401 or 403 in Vapi's logs. The call arrived from an IP not in the credential's gateways. Re-check what sip.sautikit.com resolves to and update the inbound gateway.
Outbound calls fail to authenticate. Copy the username and password again from SIP setup on the device row. The outbound gateway must use port 5080 and udp.
Outbound calls are refused by Sautikit. The destination must be E.164 (+254…). Keep outboundLeadingPlusEnabled on, and check your wallet has credit.
Sautikit's own AI agents answer the number directly, with no trunk or second account: KES 4.00 a minute, metered per second, on top of the call rate. A full comparison is on Sautikit vs Vapi, Retell and Bland.
Yes, through a bring-your-own SIP trunk. Sautikit supplies the Kenyan number, forwards inbound calls to Vapi and carries Vapi's outbound calls on the Kenyan network.
Vapi checks inbound calls against numeric IPv4 addresses, while outbound calls can go to a hostname. One gateway with Sautikit's IP takes inbound calls; one with sip.sautikit.com:5080 sends outbound calls.
The number is KES 500 a month. Inbound calls are free on Sautikit and outbound calls are KES 3.00 a minute, billed per second. Vapi charges its own per-minute platform fee.