# Migrate Multiparty and Transfer Calls

Salesforce Voice with Partner Telephony supports four multiparty patterns.

| UI Button                                                      | Pattern                                                                             | SDK Entry Point                                                                                       |
| -------------------------------------------------------------- | ----------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------- |
| Blind Transfer (when `hasBlindTransfer` capability is enabled) | Rep dials target, drops immediately.                                                | `addParticipant(contact, call, isBlindTransfer=true)`                                                 |
| New Call                                                       | Rep dials target, stays to announce, then drops.                                    | `addParticipant(contact, call, isBlindTransfer=false)`                                                |
| New Call (when `canConsult` capability is enabled)             | Rep dials a private leg while the original call is on a type of hold without music. | `dial(contact, new DialOptions({ isConsultCall: true }))`                                             |
| Add Caller                                                     | A new participant is immediately merged.                                            | `addParticipant(contact, call, isBlindTransfer=false)` with `call.callAttributes.isAutoMergeOn: true` |

:::note
The UI controls are gated by capability flags returned from `getVoiceCapabilities()`. The Blind Transfer button only appears when `hasBlindTransfer: true`. The consult variant of New Call appears only when `canConsult: true`. If you don't enable a capability, the UI control doesn't render.
:::

## VoiceCall Records and Leg Linking

Each call leg gets its own new VoiceCall record (`0LQ...`), created server-side before publishing the leg's `CALL_STARTED`. Set `parentVoiceCallId` to link the child leg back to the parent.

## Prerequisite: Declare Capabilities

```sfdocs-code {"lang":"javascript"}
async getVoiceCapabilities() {
    return new VoiceCapabilitiesResult({
        hasBlindTransfer: true,  // enables blind transfer via New Call
        canConsult: true,        // enables warm transfer and consult via New Call
        hasMerge: true,
        hasSwap: true,
    });
}
```

## Blind Transfer

The framework sends `ADD_PARTICIPANT` with `isBlindTransfer=true`. Your connector adds the new participant on the backend and returns. The framework automatically fires `HANGUP` for the original call. You don't publish it yourself.

## Warm Transfer

The framework sends `ADD_PARTICIPANT` but `isBlindTransfer=false`. The rep stays to announce the transfer, then manually ends their own leg. When the rep drops, the framework fires `PARTICIPANT_REMOVED` (not `HANGUP`).

## Consult

The rep dials a private second leg while the original call is held. The framework sends `DIAL` with `isConsultCall: true`. Then there are three options for what happens next.

| Rep Action                   | Connector Method     | Event Framework Fires         |
| ---------------------------- | -------------------- | ----------------------------- |
| Merge all into conference    | `conference(calls)`  | `PARTICIPANTS_CONFERENCED`    |
| Swap which leg is active     | `swap(call1, call2)` | `PARTICIPANTS_SWAPPED`        |
| End consult, resume original | `endCall(call)`      | `HANGUP` for consult leg only |

## Add Caller or Auto-Merge Conference

The new participant is immediately merged into a live conference. Set `isAutoMergeOn: true` in `PhoneCallAttributes` of the `ParticipantResult` so Salesforce knows to suppress the hold button for that leg.

## See Also

- [Multiparty and Consult Calls — Partner Telephony Developer Guide](https://developer.salesforce.com/docs/atlas.en-us.voice_pt_developer_guide.meta/voice_pt_developer_guide/voice_pt_multiparty_consult_calls.htm)