diff --git a/src/Tgstation.Server.Host/Components/Interop/DMApiConstants.cs b/src/Tgstation.Server.Host/Components/Interop/DMApiConstants.cs
index 37c12cc642..f5c9ffc21b 100644
--- a/src/Tgstation.Server.Host/Components/Interop/DMApiConstants.cs
+++ b/src/Tgstation.Server.Host/Components/Interop/DMApiConstants.cs
@@ -33,6 +33,22 @@ namespace Tgstation.Server.Host.Components.Interop
 		/// </summary>
 		public const string TopicData = "tgs_data";
 
+		/// <summary>
+		/// The maximum length of a BYOND side bridge request URL.
+		/// </summary>
+		/// <remarks>Testing has revealed that response size is effectively limited only by other factors like RAM.</remarks>
+		public const uint MaximumBridgeRequestLength = 8198;
+
+		/// <summary>
+		/// The maximum length in bytes of a <see cref="global::Byond.TopicSender.ITopicClient"/> payload.
+		/// </summary>
+		public const uint MaximumTopicRequestLength = 65529;
+
+		/// <summary>
+		/// The maximum length in bytes of a <see cref="global::Byond.TopicSender.ITopicClient"/> response.
+		/// </summary>
+		public const uint MaximumTopicResponseLength = 65528;
+
 		/// <summary>
 		/// The DMAPI <see cref="InteropVersion"/> being used.
 		/// </summary>