If you choose $0 Prompt Pricing, most of what it shows are models with an ID ending in :free. But it also show shows models like google/gemini-flash-1.5-8b-exp and OpenRouter's very own stealth openrouter/quasar-alpha that "just charge $0 for the input and output.
Does it mean the latter requires credits despite not using them? If so, why do you force these models when obviously the filters were meant to exclude them?
Will you consider at least having a secondary filter of "without credits - yes/no"?