A telephony configuration binds an organization to a telephony provider (Twilio, Vonage, Plivo, Telnyx, etc.) along with the credentials needed to place and receive calls. Each configuration owns a set of phone numbers; campaigns and inbound routing pin to a specific configuration. One configuration in your organization can be marked as the default outbound — campaigns and ad-hoc calls that omit telephony_configuration_id fall back to it.

​
Phone numbers

Phone numbers are nested under a configuration:

​
Sensitive credentials

Provider credentials (API keys, auth tokens, etc.) are masked in GET responses. When updating a configuration, you can re-submit the masked value as-is — EESI detects the mask and preserves the original secret.