# Create Book Transfer

Creates a new internal book transfer between bank accounts.

Endpoint: POST /accounts/{account_id}/book
Version: 1.0.0
Security: apiKeyAuth

## Path parameters:

  - `account_id` (string, required)
    The ID of the account.

## Header parameters:

  - `x-entity-id` (string)
    Optional entity ID for scoped access to entity-specific data

## Request fields (application/json):

  - `amount` (any, required)

  - `to_account_id` (string, required)

  - `description` (any)

  - `idempotency_key` (string, required)

## Response 200 fields (application/json):

  - `id` (string, required)

  - `amount` (string, required)

  - `description` (any, required)

  - `created_time` (integer, required)

  - `transfer_type` (string, required)
    Enum: "book", "usdc", "ach", "wire"

  - `to_account_id` (string, required)

  - `to_account_name` (string, required)

  - `to_account_account_number_masked` (string, required)

  - `to_entity_id` (any)

  - `to_entity_name` (any)

## Response 422 fields (application/json):

  - `detail` (array)

  - `detail.loc` (array, required)

  - `detail.msg` (string, required)

  - `detail.type` (string, required)