Fix reasoning budget for Gemini 2.5 Flash on OpenRouter

[cte]

Description

OpenRouter only tells you if a model supports the reasoning parameter in the API; it doesn't tell you if the model honors a token budget for thinking. As such we need to continue to maintain a hardcoded list.

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Important

Fixes reasoning budget handling for Gemini 2.5 Flash on OpenRouter by updating model constants and processing logic.

• Behavior:
  • Fixes reasoning budget handling for google/gemini-2.5-flash-preview-05-20 in openrouter.ts and litellm.ts.
  • Updates parseOpenRouterModel() to correctly set maxTokens and reasoning budget flags.
• Constants:
  • Renames PROMPT_CACHING_MODELS to OPEN_ROUTER_PROMPT_CACHING_MODELS and COMPUTER_USE_MODELS to OPEN_ROUTER_COMPUTER_USE_MODELS.
  • Adds OPEN_ROUTER_REASONING_BUDGET_MODELS and OPEN_ROUTER_REQUIRED_REASONING_BUDGET_MODELS to api.ts.
• Tests:
  • Updates tests in litellm.test.ts and openrouter.spec.ts to reflect new model constants and reasoning budget handling.

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[cte]

I renamed this to make it clear that it's OpenRouter specific, so it's a bit weird that we're using it in LiteLLM.

[mrubens]

Yeah... I think the idea is to pull this from LiteLLM config instead soon, right @slytechnical?

[slytechnical]

Correct. The addition of support for that has been merged in on LiteLLM's side , but I figured we should wait till that goes live in their next release before switching to it on our end

[mrubens]

LiteLLM said that we didn’t need to wait for a release since it pulls from hosted config - probably worth confirming though.

[ellipsis-dev]

There's a <pre> block rendering JSON.stringify(selectedModelInfo, null, 2). Consider removing or conditionally rendering it (e.g. only in debug mode) to avoid exposing internal details in production.

Suggested change

<pre>{JSON.stringify(selectedModelInfo, null, 2)}</pre>

[mrubens]

Is this intentional?

[cte]

No 🙈