added tools to middleware interface

Author: apascal07

go/ai/generate.go

@@ -500,6 +500,14 @@ func Generate(ctx context.Context, r api.Registry, opts ...GenerateOption) (*Mod
 		return nil, err
 	}
 
+	// Collect tools provided by middleware.
+	for _, mw := range genOpts.Use {
+		for _, t := range mw.Tools() {
+			dynamicTools = append(dynamicTools, t)
+			toolNames = append(toolNames, t.Name())
+		}
+	}
+
 	if len(dynamicTools) > 0 {
 		if !r.IsChild() {
 			r = r.NewChild()

go/ai/middleware.go

@@ -40,6 +40,9 @@ type Middleware interface {
 	Model(ctx context.Context, state *ModelState, next ModelNext) (*ModelResponse, error)
 	// Tool wraps each tool execution.
 	Tool(ctx context.Context, state *ToolState, next ToolNext) (*ToolResponse, error)
+	// Tools returns additional tools to make available during generation.
+	// These tools are dynamically registered when the middleware is used via [WithUse].
+	Tools() []Tool
 }
 
 // GenerateState holds state for the Generate hook.
@@ -93,6 +96,8 @@ func (b *BaseMiddleware) Tool(ctx context.Context, state *ToolState, next ToolNe
 	return next(ctx, state)
 }
 
+func (b *BaseMiddleware) Tools() []Tool { return nil }
+
 // Register registers the descriptor with the registry.
 func (d *MiddlewareDesc) Register(r api.Registry) {
 	r.RegisterValue("/middleware/"+d.Name, d)