look up LLM7, and Pollinations AI. Both offer free GPT 4.1, but I am not sure how limited it is. They have tons more models but the names are different (openai-large = gpt-4.1)

Meta has free and generous APIs for the crappy Llama 4 models... they're okay at summarizing things but I have no idea if its any good for code. Prob not since no one even talks about those anymore.