API uploading files to note

Hello i’am trying to upload files attached to a note, files are corrupted , looking deep to what i’am sending and what is stored into the db, i found that the mimetype i’m giving is replaced by ’ application/octet-stream’ when i upload a pdf file
this is how i create the note :
{“session”:"{SessionId}",

“module_name”:“Notes”,

“name_value_list”:{ “file_mime_type”:“application/pdf”,

“name”:“example.pdf”,

“parent_type”:“Emails”,

“parent_id”:"{Email_id}" }}

And this how i set_note_attachment:
{…,
“note” :{“id”:"{NoteId}",

“filename”: “example.pdf”,

“file”:“base64encode{FileContent}”}}

Do anyone have an idea about this ?
thanks :slight_smile: