diff --git a/.gitmodules b/.gitmodules
index eab49fa..445c0f5 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -7,3 +7,12 @@
 [submodule "external/bullet3"]
 	path = external/bullet3
 	url = https://github.com/bulletphysics/bullet3.git
+[submodule "external/Crow"]
+	path = external/Crow
+	url = https://github.com/CrowCpp/Crow.git
+[submodule "external/asio"]
+	path = external/asio
+	url = https://github.com/chriskohlhoff/asio.git
+[submodule "external/easywsclient"]
+	path = external/easywsclient
+	url = https://github.com/dhbaird/easywsclient.git
diff --git a/external/Crow b/external/Crow
new file mode 160000
index 0000000..7e41d9f
--- /dev/null
+++ b/external/Crow
@@ -0,0 +1 @@
+Subproject commit 7e41d9f52a8043b279ad52e99f634694a64aeb8e
diff --git a/external/asio b/external/asio
new file mode 160000
index 0000000..55684d4
--- /dev/null
+++ b/external/asio
@@ -0,0 +1 @@
+Subproject commit 55684d42ac00021b4c31ba8571aca414c863ead5
diff --git a/external/easywsclient b/external/easywsclient
new file mode 160000
index 0000000..afc1d8c
--- /dev/null
+++ b/external/easywsclient
@@ -0,0 +1 @@
+Subproject commit afc1d8cfc584e0f1f4a77e8c0ce3e979d9fe7ce2