# Set Shippo shipping rate for this online transaction

Set Shippo shipping rate for the transaction.
This rate will be used to purchase the Shippo label once the
transaction is paid. Shipment ID can be provided as an optional parameter,
depending on the flow which is used to obtain it.


Endpoint: POST /transactions/{transaction_id}/shippo_shipping_rate
Version: 0.1.0
Security: OAuth2

## Path parameters:

  - `transaction_id` (integer, required)

## Request fields (application/json):

  - `rate_id` (string, required)
    Example: "d755e91036a84c15bd5318f4b67c7707"

  - `shipment_id` (string)

## Response 400 fields (application/json):

  - `code` (string, required)
    Example: "negative_price"

  - `error` (string, required)
    A contextual description of the error that occurred. When
handling errors the  field should be used to determine
the type of error that occurred, as the text in the 
field may change unexpectedly.
    Example: "`price` cannot be negative"