---
title: "Start Parallel Session"
method: POST
path: "/dialer/parallel-calls/sessions/start"
tags: ["Dialer"]
---

# Start Parallel Session

`POST /dialer/parallel-calls/sessions/start`

## Request

- Base URL: `https://be.graph8.com/api/v1`
- URL: `https://be.graph8.com/api/v1/dialer/parallel-calls/sessions/start`
- Auth: HTTP bearer

*** CALLS REAL PEOPLE. *** Dials every contact in the body, at once.

One request can ring a lot of telephones. The only ceiling is voice's
per-org `MAX_LIMIT_OF_CALLS_PER_ORG_ID`; this contract does not cap
`contacts` itself, because a cap here that disagreed with voice's would
reject batches voice would have accepted.

Contacts whose number cannot be parsed are SKIPPED, not rejected - the
batch proceeds without them and the response names who was dropped. Read
it; do not assume every contact you sent was dialed.

Attempts reserve credits and connected minutes charge more. Tiered
`external`: this reaches strangers on the customer's behalf.

## Headers

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

## Request body

- StartParallelSessionRequest: Mirrors `ParallelDialRequest` minus `org_id`. THIS DIALS EVERY CONTACT.
  - `user_id` string, required
  - `user_email` 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
  - `from_phone` string, required
  - `session_id` string, nullable
  - `campaign_id` string, nullable
  - `campaign_builder_campaign_id` string, nullable
  - `session_metadata` SessionMetadataIn: Free-form session context. Open: voice grows this per release.
  - `name` 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)