1 files changed, 15 insertions, 0 deletions
diff --git a/src/SMAPI.Web/Framework/VersionConstraint.cs b/src/SMAPI.Web/Framework/VersionConstraint.cs
new file mode 100644
index 00000000..be9c0918
--- /dev/null
+++ b/src/SMAPI.Web/Framework/VersionConstraint.cs
@@ -0,0 +1,15 @@
+using Microsoft.AspNetCore.Routing.Constraints;
+
+namespace StardewModdingAPI.Web.Framework
+{
+    /// <summary>Constrains a route value to a valid semantic version.</summary>
+    internal class VersionConstraint : RegexRouteConstraint
+    {
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        public VersionConstraint()
+            : base(@"^v(?>(?<major>0|[1-9]\d*))\.(?>(?<minor>0|[1-9]\d*))(?>(?:\.(?<patch>0|[1-9]\d*))?)(?:-(?<prerelease>(?>[a-z0-9]+[\-\.]?)+))?$") { }
+    }
+}