Migrate Voice from Vapi
Inventory assistants, model and voice settings, custom tools, transferred-call behavior and the current telephony connection. Decide whether the project changes the carrier connection, the assistant runtime or both.
Map the calling behavior
For a telephony-only change, keep the assistant’s conversation behavior in its runtime and validate the new SIP connection. For a runtime replacement, reproduce tool permissions, interruption behavior and confirmed business outcomes as a separate project.
They can serve complementary roles when the SIP and media requirements of the integration match. Bird can provide the telephone connection while an assistant runtime manages the conversation. Validate both call directions, caller identity, audio and handoff before relying on that setup.
Use the call-sequence design guide to plan defined calling steps and the AI voice integration guide for a conversational runtime.
Prepare the replacement connection
Create the Bird workspace, trunk and calling identity for a controlled test. Enable the destination and configure authentication and media settings in the client. Keep existing number routing in place while evaluating the new path.
A telephone number port does not migrate the application behind it. Confirm portability and the expected cutover procedure for each country and number type. Prepare the new inbound route before relying on the number move.
Test the complete customer journey
Use a number you control and verify these outcomes:
- The intended client authenticates and the test destination rings.
- Audio works in both directions and the call ends cleanly.
- Prompts and keypad choices reach the expected branch.
- Business tools distinguish success, failure and an uncertain result.
- The call record and events connect to the outcome in your application.
- Recording or transcription, when required, produces the intended evidence.
Test a refused call and an unavailable business dependency as well as the successful path. An accepted request alone does not establish a working replacement.
Move traffic deliberately
Confirm capacity, access and the final number route. Keep a way to restore the prior route while evaluating the initial traffic. Preserve historical provider records and maintain a mapping to your application’s customer or task identity.
Reconcile rated costs after the calls finish. Include all relevant legs and any separate speech, recording or model services when comparing the new workflow.
Work with a coding agent
Paste this prompt into your coding agent with the integration you want to migrate. The numbered procedure starts with an inventory and keeps production changes explicit.
Code example
Help me evaluate a Voice migration from Vapi to Bird.
1. Read https://bird.com/docs/guides/voice/migrate/vapi.md. Use the .md alternatives of linked Bird guides for the steps below.
2. Check for a connected Bird MCP server or an installed, signed-in Bird CLI. Use whichever is available and discover its tools or command help. If neither is available, follow https://bird.com/docs/ai/set-up-your-agent.md. Do not invent operation names or install a second integration.
3. Perform a read-only inventory of my current call sites, numbers, SIP configuration, call-control instructions, event handlers, recordings, speech services and business tools. Identify secrets without printing them. Show the dependencies that stay with Vapi and the ones that need replacement.
4. Read https://bird.com/docs/guides/voice/sip-trunks.md, https://bird.com/docs/guides/voice/placing-calls.md and https://bird.com/docs/guides/voice/receiving-calls.md. Prepare the replacement connection and caller-identity requirements. Use https://bird.com/docs/guides/voice/call-sequences.md for defined menus and https://bird.com/docs/ai/voice-conversations.md for a conversational runtime. Verify each operation against the connected surface before proposing an executable step.
5. Prepare a test of one complete journey: setup, audio in both directions, keypad input, unanswered and failure paths, handoff where needed, and business-tool results. Show the exact target, configuration and expected cost before placing a call or recording audio; wait for my approval. Do not buy numbers, submit a port, change production routing or stop the existing provider without my explicit approval.
6. Use https://bird.com/docs/guides/voice/events.md and https://bird.com/docs/guides/voice/call-log.md to reconcile the outcome. Keep missing evidence and uncertain results visible. A spoken confirmation is not proof that a business action succeeded.
7. Return the integration differences, test evidence, unresolved requirements and rollback plan. Keep the current service running until I approve cutover. If a number port needs support, inspect the available support command or tool, prepare the exact request and ask for approval before submitting it. Return the ticket reference if authorized; a ticket does not schedule or complete a port.Supplier references
Next steps
Related resources
Continue with the documentation, guides and examples for this topic. Resources are in English.
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