refactor(go/plugins/googlegenai): update plugin structure

go/ai/background_model.go

@@ -52,10 +52,10 @@ type ModelOperation = core.Operation[*ModelResponse]
 // StartModelOpFunc starts a background model operation.
 type StartModelOpFunc = func(ctx context.Context, req *ModelRequest) (*ModelOperation, error)
 
-// CheckOperationFunc checks the status of a background model operation.
+// CheckModelOpFunc checks the status of a background model operation.
 type CheckModelOpFunc = func(ctx context.Context, op *ModelOperation) (*ModelOperation, error)
 
-// CancelOperationFunc cancels a background model operation.
+// CancelModelOpFunc cancels a background model operation.
 type CancelModelOpFunc = func(ctx context.Context, op *ModelOperation) (*ModelOperation, error)
 
 // BackgroundModelOptions holds configuration for defining a background model

go/ai/gen.go

@@ -334,13 +334,13 @@ type MultipartToolResponse struct {
 // Operation represents a long-running background task.
 type Operation struct {
 	// Action is the name of the action being performed by this operation.
-	Action string `json:"action,omitempty"`
+	Action string `json:"action"`
 	// Done indicates whether the operation has completed.
-	Done bool `json:"done,omitempty"`
+	Done bool `json:"done"`
 	// Error contains error information if the operation failed.
 	Error *OperationError `json:"error,omitempty"`
 	// Id is the unique identifier for this operation.
-	Id string `json:"id,omitempty"`
+	Id string `json:"id"`
 	// Metadata contains additional information about the operation.
 	Metadata map[string]any `json:"metadata,omitempty"`
 	// Output contains the result of the operation if it has completed successfully.

go/ai/generate.go

@@ -284,7 +284,7 @@ func GenerateWithRequest(ctx context.Context, r api.Registry, opts *GenerateActi
 		// Native constrained output is enabled only when the user has
 		// requested it, the model supports it, and there's a JSON schema.
 		outputCfg.Constrained = opts.Output.JsonSchema != nil &&
-			opts.Output.Constrained && outputCfg.Constrained && m.(*model).supportsConstrained(len(toolDefs) > 0)
+			opts.Output.Constrained && outputCfg.Constrained && m != nil && m.(*model).supportsConstrained(len(toolDefs) > 0)
 
 		// Add schema instructions to prompt when not using native constraints.
 		// This is a no-op for unstructured output requests.
@@ -313,12 +313,14 @@ func GenerateWithRequest(ctx context.Context, r api.Registry, opts *GenerateActi
 		Output:     &outputCfg,
 	}
 
-	fn := m.Generate
+	var fn ModelFunc
 	if bm != nil {
 		if cb != nil {
 			logger.FromContext(ctx).Warn("background model does not support streaming", "model", bm.Name())
 		}
 		fn = backgroundModelToModelFn(bm.Start)
+	} else {
+		fn = m.Generate
 	}
 	fn = core.ChainMiddleware(mw...)(fn)
 

go/core/background_action.go

@@ -33,12 +33,12 @@ type CancelOpFunc[Out any] = func(ctx context.Context, op *Operation[Out]) (*Ope
 
 // Operation represents a long-running operation started by a background action.
 type Operation[Out any] struct {
-	Action   string         // Key of the action that created this operation.
-	ID       string         // ID of the operation.
-	Done     bool           // Whether the operation is complete.
-	Output   Out            // Result when done.
-	Error    error          // Error if the operation failed.
-	Metadata map[string]any // Additional metadata.
+	Action   string         `json:"action"`             // Key of the action that created this operation.
+	ID       string         `json:"id"`                 // ID of the operation.
+	Done     bool           `json:"done"`               // Whether the operation is complete.
+	Output   Out            `json:"output,omitempty"`   // Result when done.
+	Error    error          `json:"error,omitempty"`    // Error if the operation failed.
+	Metadata map[string]any `json:"metadata,omitempty"` // Additional metadata.
 }
 
 // BackgroundActionDef is a background action that can be used to start, check, and cancel background operations.

go/internal/cmd/jsonschemagen/jsonschemagen.go

@@ -49,6 +49,11 @@ var (
 		"ModelResponseChunk": {
 			"index": {}, // fields should be as defined in core/schemas.config
 		},
+		"Operation": {
+			"action": {},
+			"done":   {},
+			"id":     {},
+		},
 	}
 )
 

go/internal/cmd/jsonschemagen/testdata/golden

@@ -181,7 +181,7 @@ type Message struct {
 type Operation struct {
 	BlockedOnStep *OperationBlockedOnStep `json:"blockedOnStep,omitempty"`
 	// If the value is false, it means the operation is still in progress. If true, the operation is completed, and either error or response is available.
-	Done bool `json:"done,omitempty"`
+	Done bool `json:"done"`
 	// Service-specific metadata associated with the operation. It typically contains progress information and common metadata such as create time.
 	Metadata any `json:"metadata,omitempty"`
 	// server-assigned name, which is only unique within the same service that originally returns it.