> ## Documentation Index
> Fetch the complete documentation index at: https://sdk.transcrypts.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Retrieve a Link Token

> Exchange a bridge public token for a link access token

## Description

This endpoint exchanges a bridge public token for a link access token, facilitating the connection between the Bridge SDK and the API. The operation enables developers to convert a public token generated by the Bridge interface into a functional access token for API operations.

## Authentication

**Required Credentials:**

* Client ID (header)
* Access Key (header)

## Request Body Parameters

| Parameter      | Type   | Required | Description                                              |
| -------------- | ------ | -------- | -------------------------------------------------------- |
| `public_token` | string | Yes      | The token received from the Bridge after user connection |

## Response

### Success Response (201 Created)

```json theme={null}
{
  "access_token": "string",
  "link_id": "string",
  "user_id": "string",
  "expires_in": "integer"
}
```

### Error Responses

**400 Bad Request:** Occurs when required parameters are missing or malformed. The response includes specific field-level validation errors.

**401 Unauthorized:** Triggered when authentication credentials are invalid or missing.

```json theme={null}
{
  "error": {
    "code": "authentication_failed",
    "message": "No such token"
  }
}
```

**403 Forbidden:** Returned when credentials lack sufficient permissions.

```json theme={null}
{
  "error": {
    "code": "not_authenticated",
    "message": "Authentication credentials were not provided."
  }
}
```