diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7d33c3c..2c165b9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ## [Unreleased]
 
+### Added
+
+- Added relay message type enums `Nostr::RelayMessageType`
+
 ### Changed
 
 - Set the gem's homepage to [`https://nostr-ruby.com/`](https://nostr-ruby.com/)
diff --git a/lib/nostr.rb b/lib/nostr.rb
index 99c27c9..55f91bb 100644
--- a/lib/nostr.rb
+++ b/lib/nostr.rb
@@ -7,6 +7,7 @@ require_relative 'nostr/client_message_type'
 require_relative 'nostr/filter'
 require_relative 'nostr/subscription'
 require_relative 'nostr/relay'
+require_relative 'nostr/relay_message_type'
 require_relative 'nostr/key_pair'
 require_relative 'nostr/event_kind'
 require_relative 'nostr/event'
diff --git a/lib/nostr/relay_message_type.rb b/lib/nostr/relay_message_type.rb
new file mode 100644
index 0000000..eca78e7
--- /dev/null
+++ b/lib/nostr/relay_message_type.rb
@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+module Nostr
+  # Clients can send 4 types of messages, which must be JSON arrays
+  module RelayMessageType
+    # @return [String] Used to notify clients all stored events have been sent
+    EOSE = 'EOSE'
+
+    # @return [String] Used to send events requested to clients
+    EVENT = 'EVENT'
+
+    # @return [String] Used to send human-readable messages to clients
+    NOTICE = 'NOTICE'
+
+    # @return [String] Used to notify clients if an EVENT was successful
+    OK = 'OK'
+  end
+end
diff --git a/sig/nostr/relay_message_type.rbs b/sig/nostr/relay_message_type.rbs
new file mode 100644
index 0000000..8a523eb
--- /dev/null
+++ b/sig/nostr/relay_message_type.rbs
@@ -0,0 +1,8 @@
+module Nostr
+  module RelayMessageType
+    EOSE: String
+    EVENT: String
+    NOTICE: String
+    OK: String
+  end
+end