LiteLLM function-calling compatibility boundary

Evidence-backed facts

1. LiteLLM normalizes function and tool-calling requests and responses across multiple supported model providers. informative
2. A completion can return tool-call names and arguments, while the client executes the corresponding function and sends the result back. informative
3. Provider credentials, proxy policy, model access, budgets, downstream tool scopes, and mutation approval are independent controls. informative
4. A normalized interface does not guarantee identical provider semantics, model support, safe arguments, external success, or a running proxy. informative

Primary sources