Transfer attachments via Service

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Leap Version: 9.3.12
Leap Deployment: Domino Leap / Standalone
Operating System: Websphere


Hi everyone,

I am trying to upload a file from an HCL Leap Attachment widget to an external REST API using a native Leap HTTP Service.

According to the external API documentation, the endpoint requires a PUT request with ⁠Content-Type: multipart/form-data⁠ and the file binary stream mapped to a form field named ⁠file⁠ (equivalent to ⁠curl -F 'file=@filename.pdf’⁠).

When I configure the service in Leap, mapping the attachment widget directly to the request entity, the Leap server throws an internal error:

⁠HTTPServiceTransport invalidResponse … Code 400⁠ / ⁠AppAdminUserException⁠.

It seems Leap has trouble transmitting the ⁠ATTACHMENT⁠ object type as a standard binary multipart body to a third-party API.

1 Is there a built-in way to configure a native Leap Service to handle external binary multipart/form-data uploads properly?

2 If not, what is the best practice or workaround to send an uploaded file from Leap to an external REST endpoint without running into CORS blocks on the client side?

Any help or sample configuration would be highly appreciated!

Thanks in advance,

Thomas