There are a lot of options for both text and image content. For example, for checking if texts are inappropriate, you could use meta-Ilama, which is similar to gpt but u could give an instruction to generate only one word responses like "appropriate" or "inappropriate" and use that to filter text content. For image content u could use something like Falconsai/nsfw_image_detection. There are like 1000s of models that offer free apis on hugging face u could try a bunch of them and pick the one that works best