Provider-Level Model Bucketing for Model Selection

[zeus2611]

What problem does this address?

Model selection is currently hardcoded in helpers.php via three static priority lists (get_preferred_models_for_text_generation(), get_preferred_image_models(), get_preferred_vision_models()). While this was an intentional design decision to prevent surprise model upgrades from breaking things or inflating costs, it creates a few pain points:

• Users with multiple API keys configured have no visibility into which provider is actually handling their tasks.
• There is no UI-level way to express a preference — customization is only possible via PHP filters, which is inaccessible to most users.
• Hardcoding specific model names is brittle given how fast the AI landscape changes, and it forces the team to make opinionated model-tier recommendations that may quickly become outdated.

What is your proposed solution?

Introduce provider-level bucketing as a middle ground between full model selection and the current fully hardcoded approach:

• Let users select a preferred provider (Anthropic, Google, or OpenAI) for text and image generation tasks, rather than picking a specific model.
• The internal model priority order within each provider remains intact — preserving the stability guarantees that were the motivation for the original design.
• Default provider values are pre-set based on the current priority logic, so behavior is unchanged for users who don't configure anything.
• This gives users meaningful visibility and control without exposing them to the complexity of individual model names.

As a longer-term direction, a capability-tier bucketing approach (e.g. fast/cheap vs. high-reasoning) could complement this — borrowing from patterns used by tools like oh-my-opencode — with an escape hatch for users who disagree with a bucket's default assignment.

This work also has natural overlap with the Playground feature (#32), which will require dynamic model input regardless, and should be designed in alignment with whatever bucketing approach we land on here.

[jeffpaul]

While I'm ok with surfacing this sort of customization, I don't think this should be exposed by default and should be hidden behind an Advanced Settings or some other such UI handling as most users will most likely enter a single AI provider and happily take the defaults from there.

[zeus2611]

Thanks @jeffpaul — that framing really helps narrow the scope.

I think the lightest-touch implementation that covers the core need would be a small "Advanced" collapsible section at the bottom of Settings > AI Experiments with just two dropdowns:

1. Text Generation Provider — Anthropic / Google / OpenAI (defaults to Anthropic, matching current priority)
2. Image Generation Provider — Google / OpenAI (defaults to Google, matching current priority)

This keeps the happy path completely unchanged — users who configure nothing see no behavior difference. But anyone who has multiple API keys configured can now explicitly express which provider they want handling each task, without needing to touch PHP filters.

Burying it in an "Advanced" accordion also keeps the main Settings UI clean and avoids surfacing model complexity to users who don't care about it. The internal model priority order within each provider stays untouched, which preserves @dkotter's stability guarantees. We're just adding a provider-level override on top.

Happy to scope out a PR for this if the approach makes sense — it should be a relatively contained change to helpers.php and the settings UI.

[jeffpaul]

@felixarntz @JasonTheAdams @dkotter any thoughts on the potential approach above?