Bridge two phone numbers (from_number ↔ destination)

Bridges two phone numbers into one call — your from_number and the destination. Because it rings two phones, it uses TWO concurrent channels. Pass connect_number to ring a separate phone for the human leg (e.g. an agent's own cell) while the destination still sees from_number; the connect_number is never shown to the destination. Supply from_number or number_set_id; exact from_number always wins when both are present. Number Sets use recipient-sticky selection among the healthiest eligible members. High-risk caller IDs return a health_warning without reputation-based blocking; inactive or technically unroutable exact numbers fail without fallback. Billing, wallet, concurrency, and contractual protections still apply. For 1-channel calls, use POST /v1/calls (AI outbound — the agent joins over the network) or the WebRTC token flow (a human joins in the browser). Returns immediately with call_id, resolved from_number, selection_source, evidence_state, health_warning, and recommended_action; poll GET /v1/calls/{id} or subscribe to webhooks for status. Demo keys must target an allowlisted destination.