Transaction Malformed

When you submit a malformed transaction to Horizon, Horizon will return a transaction_malformed error. There are many ways in which a transaction is malformed, including

  • you submitted an empty string
  • your base64-encoded string is invalid
  • your XDR structure is invalid
  • you have leftover bytes in your XDR structure

If you are encountering this error, please check the contents of the transaction you are submitting. This error is similar to the Bad Request error response and, therefore, the HTTP 400 Error.


As with all errors Horizon returns, transaction_malformed follows the Problem Details for HTTP APIs draft specification guide and thus has the following attributes:

Description Type Attribute
The identifier for the error. This is a URL that can be visited in the browser URL Type
A short title describing the error String Title
An HTTP status code that maps to the error Number Status
A more detailed description of the error String Detail
A token that uniquely identifies this request. Allows server administrators to correlate a client report with server log files String Instance

In addition, the following additional data is provided in the extras field of the error:

Description Type Attribute
The submitted data that was malformed in some way String envelope_xdr