---
title: "Create a new Sandbox Connection"
method: POST
path: "/sandbox/connections"
tags: ["Sandbox"]
---

# Create a new Sandbox Connection

`POST /sandbox/connections`

Create a new connection (new company/provider pair) with a new account

## Request body

- object
  - `provider_id` string, required — The provider associated with the connection
  - `authentication_type` 'api_token' | 'assisted' | 'credential' | 'oauth'
  - `products` string[]
  - `employee_size` integer — Optional: the size of the employer to be created with this connection. Defaults to 20. Note that if this is higher than 100, historical payroll data will not be generated, and instead only one pay period will be created.

## Response `200`

OK

- CreateSandboxConnectionResponse
  - `access_token` string, required
  - `account_id` string, uuid, required
  - `authentication_type` 'api_token' | 'assisted' | 'credential' | 'oauth', required
  - `company_id` string, uuid, nullable
  - `connection_id` string, required
  - `entity_id` string, required
  - `products` string[], required
  - `provider_id` string, required
  - `token_type` string, required

## Changes

- **2026-08-10** `f1cca2cb0ef2` — 1 breaking
  - the response property `company_id` became optional for the status `200`
- **2026-08-07** `844e1a4ed34f` — 7 breaking, 2 info
  - the `authentication_type` request property type/format changed from ``/`` to `string`/``
  - the response property `company_id` became nullable for the status `200`
  - the `access_token` response's property type/format changed from `string`/`uuid` to `string`/`` for status `200`
  - the `authentication_type` response's property type/format changed from ``/`` to `string`/`` for status `200`
  - …5 more
- **2026-07-15** `4ffde1b7d987` — 1 info
  - response property `company_id` reactivated
- **2026-01-06** `ded87cb73aff` — 1 info
  - added the required property `entity_id` to the response with the `200` status
- **2025-06-24** `f7e741bc6e01` — 1 info
  - the endpoint scheme security `basicAuth` was added to the API

[Change history](https://skmtc.dev/finch-api/apis/api-reference/changes/sandbox/connections/post.md)

---

[API](https://skmtc.dev/finch-api/apis/api-reference.md) · [All operations](https://skmtc.dev/finch-api/apis/api-reference/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/finch-api/api-reference/revisions/f1cca2cb0ef2/schema)