diff --git a/pkg/models/post.go b/pkg/models/post.go
index e2d4b9b..9c13b39 100644
--- a/pkg/models/post.go
+++ b/pkg/models/post.go
@@ -1,6 +1,6 @@
 package models
 
 type AnthrovePost struct {
-	PostID AnthrovePostID `json:"post_id"`
-	Rating AnthroveRating `json:"rating"`
+	PostID AnthrovePostID `json:"post_id" format:"string"`
+	Rating AnthroveRating `json:"rating" format:"string"`
 }
diff --git a/pkg/models/relationships.go b/pkg/models/relationships.go
index f62e134..5f8e5fe 100644
--- a/pkg/models/relationships.go
+++ b/pkg/models/relationships.go
@@ -1,12 +1,12 @@
 package models
 
 type AnthroveUserRelationship struct {
-	UserID             string         `json:"user_id"`
-	Username           string         `json:"username"`
-	ScrapeTimeInterval string         `json:"scrape_time_interval"`
+	UserID             string         `json:"user_id" format:"string"`
+	Username           string         `json:"username" format:"string"`
+	ScrapeTimeInterval string         `json:"scrape_time_interval" format:"string"`
 	Source             AnthroveSource `json:"source"`
 }
 type AnthrovePostRelationship struct {
-	PostID string `json:"post_id"`
-	Url    string `json:"url"`
+	PostID string `json:"post_id" format:"string"`
+	Url    string `json:"url" format:"string"`
 }
diff --git a/pkg/models/source.go b/pkg/models/source.go
index 00040ae..27a4835 100644
--- a/pkg/models/source.go
+++ b/pkg/models/source.go
@@ -1,7 +1,7 @@
 package models
 
 type AnthroveSource struct {
-	DisplayName string `json:"display_name"`
-	Domain      string `json:"domain"`
-	Icon        string `json:"icon"`
+	DisplayName string `json:"display_name" format:"string"`
+	Domain      string `json:"domain" format:"string"`
+	Icon        string `json:"icon" format:"string"`
 }
diff --git a/pkg/models/tag.go b/pkg/models/tag.go
index 8d0d1e6..49ae70b 100644
--- a/pkg/models/tag.go
+++ b/pkg/models/tag.go
@@ -1,6 +1,6 @@
 package models
 
 type AnthroveTag struct {
-	Name string `json:"name"`
-	Type string `json:"type"`
+	Name string `json:"name" format:"string"`
+	Type string `json:"type" format:"string"`
 }
diff --git a/pkg/models/user.go b/pkg/models/user.go
index af6e36c..3b49921 100644
--- a/pkg/models/user.go
+++ b/pkg/models/user.go
@@ -1,6 +1,6 @@
 package models
 
 type AnthroveUser struct {
-	UserID       AnthroveUserID             `json:"user_id"`
+	UserID       AnthroveUserID             `json:"user_id" format:"string"`
 	Relationship []AnthroveUserRelationship `json:"relationship"`
 }