---
title: "Start Call"
method: POST
path: "/gemini-live/start_call"
tags: ["gemini-live"]
---

# Start Call

`POST /gemini-live/start_call`

Initiate an outbound call via the configured telephony provider.

## Request body

- OutboundCallBody
  - `to_number` string, required
  - `from_number` string, required
  - `system_prompt` string, required
  - `call_provider` string
  - `language_code` string, nullable
  - `voice_id` string, nullable
  - `telephony_provider` string, nullable
  - `agent_talks_first` boolean
  - `custom_first_message` string, nullable
  - `knowledge_base_id` string, nullable
  - `usecase_industry` string, nullable
  - `enable_deviation_tool` boolean
  - `enable_manager_transfer` boolean
  - `corpus_url` string[], nullable
  - `corpus_file_path` string[], nullable
  - `workspace_id` string, nullable
  - `use_case_id` string, nullable
  - `scheduling_enabled` boolean
  - `outcaller_call_id` string, nullable

## Response `200`

Successful Response

- unknown

## Other responses

- `422` — Validation Error

## Changes

> 16 revisions in range; 3 could not be searched.

- **2026-07-31** `7c9aff2501f3` — 2 warning, 2 info
  - removed the request property `campaign_id`
  - removed the request property `campaign_industry`
  - added the new optional request property `use_case_id`
  - added the new optional request property `usecase_industry`
- **2026-07-26** `e7248cb2f50b` — 3 info
  - added the new optional request property `campaign_id`
  - added the new optional request property `outcaller_call_id`
  - added the new optional request property `scheduling_enabled`

[Change history](https://skmtc.dev/outcallerai/apis/fastapi/changes/gemini-live/start_call/post.md)

---

[API](https://skmtc.dev/outcallerai/apis/fastapi.md) · [All operations](https://skmtc.dev/outcallerai/apis/fastapi/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/outcallerai/fastapi/revisions/6155db644bab/schema)