OpenRouter also has an endpoint for listing models (with pricing info) in its api: https://openrouter.ai/docs/overview/models

A limitation though, at least the last time I checked, is that you only get a single provider returned per model. That’s fine for the major commercial models that all have the same pricing on each provider, but makes it hard to rely on for open source models, which tend to have many providers offering them at different price points (sometimes very different price points—like 5x or 10x difference).