Retell
Retell is the first and only provider implemented today. The integration is built on the official retell-sdk, pinned exactly to 5.48.0 in the root package.json and package-lock.json as of 2026-07-27.
The vac retell namespace covers:
| Area | Command groups |
|---|---|
| Authentication | login |
| Agents and prompts | agents, agent, agent-publish, prompts, tools, tests |
| Calls | calls, transcripts, batch-calls, exports, concurrency |
| Response engines | llms, flows, flow-components |
| Chat | chat-agents, chats, playground |
| Other resources | phone-numbers, voices, kb |
Use generated help for the exact operations and flags because command groups do not share a universal CRUD surface:
vac retell --helpvac retell phone-numbers --helpMost commands use the SDK client in src/providers/retell/services/retell-client.ts. Live-call updates and agent environment tags use the same authenticated client with explicit Retell HTTP paths because those operations are not exposed through the pinned SDK’s resource helpers.
Inspect and assign environment tags through the agent namespace:
vac retell agents tags get agent_123 prodvac retell agents tags assign agent_123 prod --agent-version 4 --dry-runvac retell agents tags assign agent_123 prod --agent-version 4The assignment command requires an existing tag and version, preserves the complete tag map and dynamic variables, and verifies the selected tag after the update. Moving prod changes production traffic immediately.
Phone-number bindings can resolve through a tag instead of a fixed numeric version:
vac retell phone-numbers update +14157774444 \ --inbound-agent agent_123 \ --inbound-agent-version prodThe paired outbound flags are --outbound-agent and --outbound-agent-version. Read the number before and after the update because replacing a single-agent binding is an immediate routing change.
Read API compatibility before updating the SDK or sending raw Retell payloads.