Sahil
06/13/2025, 5:52 AMVapi Support Bot
06/13/2025, 5:54 AMX-Context-ID SIP header) on inbound SIP calls, configure your Vapi phone number to use a server URL instead of a static dashboard assistant. When a call arrives, Vapi will POST an assistant-request event to your server, including SIP headers in the payload. You can extract the UUID like this:
js
app.post("/api/assistant-selector", (req, res) => {
const uuid = req.body.call?.sipHeaders?.['x-context-id'];
// Use the UUID as needed
res.json({ assistantId: "your-assistant-id" });
});
Note: This approach requires switching from a dashboard-assigned assistant to a server URL/webhook configuration.
[See docs for details](https://docs.vapi.ai/advanced/sip#send-sip-headers-to-fill-template-variables)
Sources:
- [SIP integration documentation](https://docs.vapi.ai/advanced/sip)
- [Personalization with user information](https://docs.vapi.ai/assistants/personalization)Kings_bigđź’«
06/13/2025, 12:46 PMaxespire_57158
06/19/2025, 7:20 PMChiranjeet Mishra
06/20/2025, 4:37 PMX-Context-ID SIP header isn't extracted using the “Get SIP Headers” action; outbound calls fail with “Tool ID does not exist” if the VAPI assistant is referencing a tool ID that hasn’t been defined in its configuration..