---
title: "Prewarm Voicemails"
method: POST
path: "/dialer/sessions/prewarm-voicemails"
tags: ["Dialer"]
---

# Prewarm Voicemails

`POST /dialer/sessions/prewarm-voicemails`

## Request

- Base URL: `https://be.graph8.com/api/v1`
- URL: `https://be.graph8.com/api/v1/dialer/sessions/prewarm-voicemails`
- Auth: HTTP bearer

CONTACTS NOBODY - but it SPENDS. Synthesises voicemail audio in advance.

Text-to-speech is generated per contact and cached so the audio is ready
before a rep clicks Start Dialing. No phone rings and no one hears
anything, but it is real generation work per contact, which is why it is
tiered `billable` rather than a plain `write`.

Returns immediately - the work is fired in the background. Duplicates are
no-ops (Redis in-flight lock plus a per-contact cache). Voice caps the
batch at 20 and so does this contract.

## Headers

- `Authorization` string, nullable
- `X-Target-Org-Id` string, nullable

## Request body

- PrewarmVoicemailsRequest: Mirrors `DialerPrewarmRequest` minus `org_id`. SYNTHESISES voicemail audio ahead of time. Contacts nobody, but it is real text-to-speech work per contact, which is why it is not a plain write. Voice caps the batch at 20 and that cap is mirrored here so an oversized batch is a 422 from this API rather than a round-trip.
  - `agent_id` string, nullable
  - `contacts` DialContact[], required
    - `contact_id` string, required
    - `to_phone` string, required
    - `first_name` string, nullable
    - `last_name` string, nullable
    - `email` string, nullable
    - `company` string, nullable
    - `title` string, nullable
    - `timezone` string
    - `default_region` string, nullable
    - `all_phones` object[], nullable
    - `phone_index` integer, nullable
    - `dynamic_columns` object, nullable
    - `is_redial` boolean, nullable
    - `redial_count` integer, nullable
    - `original_call_id` string, nullable

## Response `200`

Successful Response

- ApiResponseDialerPayload
  - `data` DialerPayload, required: An open envelope for one dialer result. Open because voice owns the shape of a session, a call stub and a queue stat, and it grows them without a contract bump here. A dropped field would otherwise turn an added upstream field into a removed public one.
  - `pagination` PaginationMeta
    - `page` integer, required: Current page number (1-indexed)
    - `limit` integer, required: Items per page
    - `total` integer, required: Total number of items
    - `has_next` boolean, required: Whether there are more pages
    - `next_cursor` string, nullable: Opaque cursor for the next page; null when there are no more items. Pass it back as the `cursor` query param to fetch the following page without computing page numbers.
    - `total_available` integer, nullable: Search endpoints only: how many records really match, when known. Can be larger than `total`, which is capped at the 10,000 results that can be paged. For company search this is a distinct-company estimate. Null when unknown; absent outside search.
    - `total_is_lower_bound` boolean, nullable: Search endpoints only: true when more records match than `total` shows (the result set is larger than the 10,000 results that can be paged). Absent outside search.
    - `notes` string[], nullable: Search endpoints only: plain-language notes about the result, e.g. that more records match than can be paged, or that a reversed `between` range was put in order.

## Other responses

- `422`: Validation Error

---

[API](https://skmtc.dev/graph8/apis/graph8-developer-api.md) · [All operations](https://skmtc.dev/graph8/apis/graph8-developer-api/llms.txt) · [OpenAPI document](https://skmtc.dev/graph8/apis/graph8-developer-api/revisions/2e7cfa0ca921?raw)