diff --git a/meson.build b/meson.build
index 47f07c6..b8c86e0 100644
--- a/meson.build
+++ b/meson.build
@@ -2,7 +2,7 @@ project('gigagrad', 'cpp', default_options : ['cpp_std=c++20'])
 gigagrad = library('gigagrad', 'src/graph.cpp')
 
 test_deps = [dependency('catch2-with-main')]
-vizserver_deps = [dependency('cpp-httplib')]
+vizserver_deps = [dependency('cpp-httplib'), dependency('nlohmann_json')]
 executable('gigagrad-test', 'test/graph-test.cpp', dependencies : test_deps, link_with : gigagrad)
 executable('gigagrad-viz-server', 'src/gigagrad_viz_server.cpp',
            dependencies : vizserver_deps,
diff --git a/src/gigagrad_viz_server.cpp b/src/gigagrad_viz_server.cpp
index 6647d72..0423994 100644
--- a/src/gigagrad_viz_server.cpp
+++ b/src/gigagrad_viz_server.cpp
@@ -1,6 +1,32 @@
 #include "httplib.h"
+#include "nlohmann/json.hpp"
+
+using json = nlohmann::json;
+
+
+void StartServer() {
+    httplib::Server svr;
+
+    svr.Get("/test-tensor", [](const httplib::Request &, httplib::Response &res) {
+        const json test_tensor = {
+            {"shape", {1, 6, 6, 3}},
+            {"buffer", {
+                1, 1, 1, 2, 2, 2, 3, 3, 3, 4, 4, 4, 5, 5, 5, 6, 6, 6,
+                2, 2, 2, 3, 3, 3, 4, 4, 4, 5, 5, 5, 6, 6, 6, 7, 7, 7,
+                3, 3, 3, 4, 4, 4, 5, 5, 5, 6, 6, 6, 7, 7, 7, 8, 8, 8,
+                3, 3, 3, 4, 4, 4, 5, 5, 5, 6, 6, 6, 7, 7, 7, 8, 8, 8,
+                3, 3, 3, 4, 4, 4, 5, 5, 5, 6, 6, 6, 7, 7, 7, 8, 8, 8,
+                3, 3, 3, 4, 4, 4, 5, 5, 5, 6, 6, 6, 7, 7, 7, 8, 8, 8
+            }}
+        };
+        res.set_content(test_tensor.dump(), "application/json");
+    });
+
+    svr.listen("0.0.0.0", 8080);
+}
 
 int main()
 {
+    StartServer();
     return 0;
 }
diff --git a/subprojects/nlohmann_json.wrap b/subprojects/nlohmann_json.wrap
new file mode 100644
index 0000000..bf5d700
--- /dev/null
+++ b/subprojects/nlohmann_json.wrap
@@ -0,0 +1,10 @@
+[wrap-file]
+directory = nlohmann_json-3.11.2
+lead_directory_missing = true
+source_url = https://github.com/nlohmann/json/releases/download/v3.11.2/include.zip
+source_filename = nlohmann_json-3.11.2.zip
+source_hash = e5c7a9f49a16814be27e4ed0ee900ecd0092bfb7dbfca65b5a421b774dccaaed
+wrapdb_version = 3.11.2-1
+
+[provide]
+nlohmann_json = nlohmann_json_dep