I’m afraid not, that in itself is another conspiracy theory as there is evidence of its use as early as the 19th century
The problem with conspiracy theories isn’t so much that conspiracies don’t exist, they of course do. The problem is the alacrity with which those who believe conspiracies often show the same amount of credulousness that they attribute to others and often there is a need for conspiracies to be interlinked.
The CIA is a clandestine organisation therefore it’s going to be at the forefront of conspiracy. And of course it has conducted numerous black ops both at home and abroad including both not limited to influencing coups in countries like Guatemala, Chile, Greece, Iran etc.
The Kennedy conspiracies never really hold up to examination. Most of Oliver Stones film for example ranges from distortion and supposition to outright fiction.
Whether he was a CIA operative I can’t say, but it’s been proved pretty conclusively that Lee Harvey Oswald was the lone gunman responsible for Kennedy’s death.