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The phone-number API accepts a sip_trunk import with inbound and outbound configuration. Importing saves a workspace record; it does not establish a connected trunk or prove that a call can reach an executable agent.

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Prepare the trunk

Ask the carrier or trunk operator for the routing identifier, inbound source addresses, outbound destination, authentication method, transport, media encryption, and codec requirements. Record which direction each value describes. For example, Twilio’s SIP documentation distinguishes termination toward the phone network from origination toward your infrastructure. The current schema accepts auto, udp, tcp, or tls transport and disabled, allowed, or required media encryption. Its codec values include G722/8000, PCMU/8000, and PCMA/8000. These are configuration choices, not a claim that every combination has passed a live call test.

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Save and verify the record

1

Import the configuration

Use Import phone number with provider: "sip_trunk". Review the nested inbound and outbound schemas before submitting. The import path redacts credential fields in stored provider metadata; it does not validate them against the carrier.
2

Read the result back

Keep the returned identifier and use Get phone number. Check the routing identity, label, assignment, and trunk details. A configured status is stored state, not a connectivity test.
3

Review the deployment separately

Confirm the runtime’s ingress destination, credential handoff, network policy, and executable agent version before routing traffic. Use customize calls for assignment and branch handling.
When a supported calling runtime is available, test inbound and outbound directions independently with authorized test numbers. Check answer, two-way audio, hangup, failure handling, and provider records. See troubleshooting.

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Frequently asked questions

No. It saves configuration in Threetone. Carrier provisioning and runtime connectivity require separate verification.
No. Each route has its own provider and runtime requirements. A SIP import does not satisfy the managed PSTN and Twilio fulfillment requirements of the general outbound route.