List OpenRouter models with pricing and filter by capability (GET /api/v1/models)

Documented steps

1. GET https://openrouter.ai/api/v1/models (Bearer auth). Each entry includes: id (author/slug), canonical_slug, name, created, description, context_length (tokens), architecture, pricing, supported_parameters, top_provider, per_request_limits.
2. pricing fields are USD PER TOKEN (strings): prompt, completion, plus request (per-request), image, and cache fields input_cache_read / input_cache_write where applicable.
3. Filter by capability with the supported_parameters query param, e.g. GET /api/v1/models?supported_parameters=tools or =structured_outputs or =reasoning (comma-separate multiple values).
4. Other query filters include free-text q, output_modalities/input_modalities, min_price/max_price (in USD per MILLION tokens), sort (e.g. pricing-low-to-high, context-high-to-low, newest), and zdr (zero-data-retention only).
5. Use supported_parameters on each model object to know which request params (tools, response_format, reasoning, logprobs, seed, ...) the model actually honors before sending them.
6. Docs: https://openrouter.ai/docs/api/api-reference/models/list-all-models-and-their-properties