diff --git a/nix/agent-js/agent-js-monorepo.nix b/nix/agent-js/agent-js-monorepo.nix
index a7a943a5f0..b432821293 100644
--- a/nix/agent-js/agent-js-monorepo.nix
+++ b/nix/agent-js/agent-js-monorepo.nix
@@ -6,10 +6,23 @@
 , agentJsMonorepoTools ? import ./monorepo-tools.nix { inherit pkgs system; }
 }:
 let
+  npmEnvironmentBuildInput = (pkgs.stdenv.mkDerivation {
+    name="agent-js-monorepo-env";
+    src=agent-js-monorepo-src;
+    # Without this unsetting HOME, npm might try to write to default HOME=/homeless-shelter
+    HOME="";
+    installPhase = ''
+      mkdir -p $out
+    '';
+  });
   monorepo = pkgs.napalm.buildPackage agent-js-monorepo-src {
     name = "agent-js-monorepo";
     propagatedBuildInputs = [
       (agentJsMonorepoTools agent-js-monorepo-src)
+      npmEnvironmentBuildInput
+    ];
+    buildInputs = [
+      npmEnvironmentBuildInput
     ];
     outputs = [
       "out"
@@ -17,6 +30,10 @@ let
       "agent"
       "bootstrap"
     ];
+    # HOME = "";
+    npmCommands = [
+      "npm install"
+    ];
     installPhase = ''
       # $out: Everything!
       mkdir -p $out