diff --git a/pkgs/tools/networking/cassowary/default.nix b/pkgs/tools/networking/cassowary/default.nix
new file mode 100644
index 000000000000..bc1f9cebb42f
--- /dev/null
+++ b/pkgs/tools/networking/cassowary/default.nix
@@ -0,0 +1,23 @@
+{ lib, buildGoModule, fetchFromGitHub, writeText, runtimeShell, ncurses, }:
+
+buildGoModule rec {
+  pname = "cassowary";
+  version = "0.3.0";
+
+  src = fetchFromGitHub {
+    owner = "rogerwelin";
+    repo = pname;
+    rev = "33b7e81a5d147980f4ddc689818df2b071f6ab4e";
+    sha256 = "01cdmh2v9rz8rna08hdsddllck6zp9wcrhxdy6hs77zfsbzyfflx";
+  };
+
+  modSha256 = "1iylnnmj5slji89pkb3shp4xqar1zbpl7bzwddbzpp8y52fmsv1c";
+
+  meta = with lib; {
+    homepage = "https://github.com/rogerwelin/cassowary";
+    description = "Modern cross-platform HTTP load-testing tool written in Go ";
+    license = licenses.mit;
+    maintainers = with maintainers; [ hugoreeves ];
+    platforms = platforms.unix;
+  };
+}
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 2b557f40e3ba..d80529f27379 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -1381,6 +1381,8 @@ in
 
   ccnet = callPackage ../tools/networking/ccnet { };
 
+  cassowary = callPackage ../tools/networking/cassowary { };
+
   croc = callPackage ../tools/networking/croc { };
 
   cddl = callPackage ../development/tools/cddl { };