> ## Documentation Index
> Fetch the complete documentation index at: https://developers.callaro.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Twilio

> Configure Twilio-backed SIP or PSTN flows for number search, purchase, and inbound/outbound calling.

# Use Twilio when you want mature number inventory and programmable telephony.

## Prerequisites

* Twilio account and credentials
* A telephony connection configured for the tenant
* Approved inbound and outbound countries
* Ops owner for number health monitoring

<Steps>
  <Step title="Create telephony connection">
    Configure Twilio connection in Callaro and verify credentials with a connection test.
  </Step>

  <Step title="Provision number inventory">
    Use `phone_numbers/available`, `purchase`, or `import_owned` depending on ownership model.
  </Step>

  <Step title="Configure webhook and callback paths">
    Validate call status and inbound routing callback compatibility before launch.
  </Step>

  <Step title="Run supervised smoke tests">
    Execute inbound and outbound test calls and verify session logs, recordings, and webhook delivery.
  </Step>
</Steps>

## Mapping guidance

* Twilio call SID should be stored as external reference for debugging.
* Map Twilio number inventory labels to campaign and region ownership.
* Keep provider-level webhook secret rotation in ops runbook.

## Validation checklist

* Number can place and receive test calls.
* Call status reaches `voice_sessions` consistently.
* Recording links resolve where recording is enabled.
* Retry behavior is acceptable during temporary provider failures.

## Known limits

* Carrier behavior differs by geography and can affect answer rates.
* Rapid high-volume ramp without warm-up increases spam risk.
* Provider-side webhook latency can impact near-real-time automations.

<Note>When Twilio is your primary provider, tie number-health alerts to campaign velocity controls.</Note>

## What to do next

* Review [`../api-reference/phone-numbers/overview`](../api-reference/phone-numbers/overview) for provisioning and inventory workflows.
* Review [`../guides/inbound-calling`](../guides/inbound-calling) before enabling live inbound traffic.
* Review [`../api-reference/webhooks/overview`](../api-reference/webhooks/overview) to validate provider callback handling.