diff --git a/internal/repotools/cmd/gencrosslink/main.go b/internal/repotools/cmd/gencrosslink/main.go
new file mode 100644
index 00000000000..06ab0fdea17
--- /dev/null
+++ b/internal/repotools/cmd/gencrosslink/main.go
@@ -0,0 +1,197 @@
+// package main is the cmd
+package main
+
+import (
+ "encoding/json"
+ "flag"
+ "fmt"
+ "io"
+ "io/ioutil"
+ "os"
+ "path"
+ "strings"
+)
+
+type shapeType string
+
+const (
+ shapeTypeService shapeType = "service"
+ // ...
+)
+
+type smithyModel struct {
+ Shapes map[string]smithyShape `json:"shapes"`
+}
+
+func (m *smithyModel) Service() *serviceShape {
+ for _, s := range m.Shapes {
+ if s.typ == shapeTypeService {
+ return s.asService()
+ }
+ }
+ panic("no service shape found")
+}
+
+type smithyShape struct {
+ typ shapeType
+ raw []byte
+}
+
+func (s *smithyShape) UnmarshalJSON(p []byte) error {
+ var head = struct {
+ Type shapeType `json:"type"`
+ }{}
+ if err := json.Unmarshal(p, &head); err != nil {
+ return nil
+ }
+
+ s.typ = head.Type
+ s.raw = p
+ return nil
+}
+
+func (s *smithyShape) asService() *serviceShape {
+ var shape serviceShape
+ if err := json.Unmarshal(s.raw, &shape); err != nil {
+ panic(err)
+ }
+
+ return &shape
+}
+
+type serviceShape struct {
+ Version string `json:"version"`
+ Traits smithyTraits `json:"traits"`
+}
+
+type smithyTraits map[string]json.RawMessage
+
+func (ts smithyTraits) ServiceTrait() (*serviceTrait, bool) {
+ const traitID = "aws.api#service"
+
+ raw, ok := ts[traitID]
+ if !ok {
+ return nil, false
+ }
+
+ var v serviceTrait
+ if err := json.Unmarshal(raw, &v); err != nil {
+ panic(err)
+ }
+
+ return &v, true
+}
+
+type serviceTrait struct {
+ SdkID string `json:"sdkId"`
+ DocID string `json:"docId"`
+}
+
+func loadModels(dir string) ([]smithyModel, error) {
+ files, err := ioutil.ReadDir(dir)
+ if err != nil {
+ return nil, fmt.Errorf("read models dir: %w", err)
+ }
+
+ var models []smithyModel
+ for _, file := range files {
+ f, err := os.Open(path.Join(dir, file.Name()))
+ if err != nil {
+ return nil, fmt.Errorf("open %s: %w", file.Name(), err)
+ }
+
+ p, err := io.ReadAll(f)
+ if err != nil {
+ return nil, fmt.Errorf("read %s: %w", file.Name(), err)
+ }
+
+ var model smithyModel
+ if err := json.Unmarshal(p, &model); err != nil {
+ return nil, fmt.Errorf("unmarshal %s: %w", file.Name(), err)
+ }
+
+ models = append(models, model)
+ }
+ return models, nil
+}
+
+func mtoc(model *smithyModel) (docID, pkgName string) {
+ service := model.Service()
+ serviceTrait, ok := service.Traits.ServiceTrait()
+ if !ok {
+ panic("no service trait")
+ }
+
+ pkgName = topkg(serviceTrait.SdkID)
+ docID = serviceTrait.DocID
+ if docID == "" {
+ docID = fmt.Sprintf("%s-%s", normalize2(serviceTrait.SdkID), service.Version)
+ }
+ return
+}
+
+func topkg(sdkID string) (pkg string) {
+ pkg = strings.ToLower(sdkID)
+ pkg = strings.Replace(pkg, " ", "", -1)
+ pkg = strings.Replace(pkg, "-", "", -1)
+ return
+}
+
+func normalize2(sdkID string) (v string) {
+ v = strings.ToLower(sdkID)
+ v = strings.Replace(v, " ", "-", -1)
+ return
+}
+
+func main() {
+ var modelsDir string
+ flag.StringVar(&modelsDir, "modelsDir", "", "full path to aws-models directory")
+ flag.Parse()
+ if modelsDir == "" {
+ panic("modelsDir not set")
+ }
+
+ models, err := loadModels(modelsDir)
+ if err != nil {
+ panic(err)
+ }
+
+ docToPkg := map[string]string{}
+ for _, model := range models {
+ doc, pkg := mtoc(&model)
+ docToPkg[doc] = pkg
+ }
+
+ var mapping string
+ for k, v := range docToPkg {
+ mapping += fmt.Sprintf(" '%s': '%s',\n", k, v)
+ }
+
+ page := `<!DOCTYPE html>
+<html>
+ <script type="text/javascript">
+ (function() {
+ var docToPkg = {
+` + mapping + ` };
+
+ var query = new URL(window.location.href).searchParams;
+ var docId = query.get('doc');
+ var operation = query.get('operation');
+ if (docId === null || operation === null) {
+ window.location = 'https://pkg.go.dev/github.com/aws/aws-sdk-go-v2';
+ return;
+ }
+
+ var service = docToPkg[docId];
+ if (service === undefined) {
+ window.location = 'https://pkg.go.dev/github.com/aws/aws-sdk-go-v2';
+ return;
+ }
+
+ window.location = 'https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/' + service + '#Client.' + operation;
+ })();
+ </script>
+</html>`
+
+ fmt.Println(page)
+}