Problem adding files with ColdFusion via Monday.com API

[jkw4703 (accepted answer)]: Three issues were breaking the upload. 1) Line endings: literal backslash-r-backslash-n sequences in the ColdFusion source were sent as-is; replacing them with chr(13) and chr(10) produced real CRLF bytes. 2) The GraphQL mutation text did not match the documented add_file_to_column shape; reformatting the query per the docs fixed the server-side parse. 3) ColdFusion compiles single-quoted and double-quoted strings differently, so mixed quoting corrupted the payload; escaping the double quotes and dropping the single quotes made it work. Working approach: build the multipart body in a string variable - boundary delimiter lines, a Content-Disposition part carrying the GraphQL mutation, then a second part with the file's binary content and an application/octet-stream content type, all joined with CRLF.

Context: Stack Overflow #71641641 (accepted answer, 4 votes): uploading a file to the Monday API from ColdFusion. The asker had items, updates, columns, boards, and reads working, but file upload kept failing. They were porting a NodeJS multipart-upload example ('Uploading a file to monday.com, the hard way') to ColdFusion and building the multipart body by hand with string concatenation.