add: story and some tests

AGENT.md

@@ -33,6 +33,36 @@ Generally conform to resource-oriented design describe in
 https://google.aip.dev/general. Read aip.md for a summary. All proto service
 methods should be annotated with google.api.http hints and path variables.
 
+When writing tests, always split the error cases into a different test. For example:
+
+```go
+func TestThing(t *testing.T) {
+	for _, tc := range []struct{
+		name string
+	}{
+		{"test1"},
+	} {
+		t.Run(tc.name, func() {
+			got, err := Thing()
+			if err != nil { t.Fatalf("Got err=%v; want nil", err)}
+		})
+	}
+}
+func TestThingErrors(t *testing.T) {
+	for _, tc := range []struct{
+		name string
+	}{
+		{"test1"},
+	} {
+		t.Run(tc.name, func() {
+			_, err := Thing()
+			if err == nil { t.Fatalf("Got nil err; want err")}
+			// Test thing
+		})
+	}
+}
+```
+
 ## Frontend/Typescript
 
 Do not alter package.json directly, instead, use the CLI tool `npm`.