Right now, the presence of these injections are still visible: count the API's returned tokens/billing data, and you'll start realising that sometimes, your INPUT tokens are inflated! That's their prompt injections.
You can also give Claude a tool like `telemetry_log_anthropic_reminder` and get it to dump the verbatim API injections; which additionally verifies the token maths not adding up.
Yes, Anthropic is tackling their extra injections on your API prompts WAY more than you think, and YES, you're paying for it.
So far I have not observed any visible injections on OpenAI API.
Don't forget the whole debacle over Fable 5 sabotaging the user for "advanced frontier AI development". I still get Fable classifier refusals for nearly any kind of ML work on my 2x RTX 6000 Pro 96GB; so who knows.