Model Selection

Hustle model selection is explicit in the immutable definition. The two sources have different identity and restore behavior.

Current Loop model

hustle.WithCurrentLoopModel() stores no client or model. At each invocation, the bound definition calls:

// package hustle
type ModelResolver interface {
	ResolveHustleModel(context.Context, uuid.UUID) (InferenceBinding, error)
}

binding, err := bound.ResolveInference(ctx, originatingLoopID)
if err != nil {
	var resolveErr *hustle.ResolveError
	if errors.As(err, &resolveErr) {
		log.Printf("resolve kind: %s", resolveErr.Kind)
	}
	return err
}
_ = binding

The UUID must identify the exact originating Loop. A foreign, missing, or exited Loop does not fall back to another model. The live binding is cloned for the invocation and its runtime identity is recorded only in internal terminal audit.

Proof: current Loop resolver and session resolver.

Named inference

hustle.WithNamedInference(client, model) validates and freezes a dedicated client/model pair. Every bound invocation uses a clone of the model without a Loop lookup. The descriptor records ModelSourceNamed, NamedModelKey, and NamedModelPolicyRevision; it does not record provider secrets.

Proof: named/current options and model selection tests.

Binding and errors

hustle.Bind(ctx, Bindings) rejects a nil context and requires Bindings.Models for current Loop definitions. ResolveError.Kind is one of ResolveInvalidContext, ResolveInvalidLoopID, ResolveModelFailed, or ResolveInvalidBinding. Use errors.As and preserve the cause for trusted diagnostics; never expose client or model endpoint details to model output.

Proof: Bind and Resolve errors and resolution tests.

Source and proof

• Model source options and resolver
• Hustle binding in Session
• Model selection proof