### Check for existing issues

- [x] I have searched the existing issues and checked that my issue is not a duplicate.

### The Feature

Add support for defining a shared budget at the model_group level for an API key. All models within the group should draw from the same combined budget.

### Motivation, pitch

Teams may want to limit developer spending on a family of expensive models, such as multiple Claude Opus versions. Today, budgets can be set per individual model, but each model receives its own limit. This means developers can exceed the intended total cap by using several models in the same expensive family. A model-group budget would allow configuring one shared limit across models—for example, a single monthly budget covering all Opus model versions—so usage is enforced against the combined spend rather than per-model spend.

### What part of LiteLLM is this about?

Proxy

### LiteLLM is hiring a founding backend engineer, are you interested in joining us and shipping to all our users?

No

### Twitter / LinkedIn details

_No response_