diff --git a/flake.nix b/flake.nix
index 880b358..48a3f86 100644
--- a/flake.nix
+++ b/flake.nix
@@ -78,9 +78,34 @@
             franUpdate
           ];
         };
+        newpkg = pkgs.mkShell {
+          nativeBuildInputs = [
+            pkgs.nix-prefetch-github
+          ];
+        };
+      }
+    );
+
+    checks = forAllSystems (
+      system: let
+        pkgs = import nixpkgs {
+          inherit system;
+          overlays = [self.overlays.default];
+        };
+        rEnv = mkR {
+          inherit pkgs;
+          packages = builtins.attrValues pkgs.extraRPackages;
+        };
+      in {
+        test-script = pkgs.runCommand "test-script" {} ''
+          mkdir -p $out
+          cp ${./test/test.R} test.R
+          ${rEnv}/bin/Rscript test.R > $out/result.log
+        '';
       }
     );
   };
+
   nixConfig = {
     extra-substituters = [
       "https://rstats-on-nix.cachix.org"
diff --git a/packages/default.nix b/packages/default.nix
index be7a47e..cc02591 100644
--- a/packages/default.nix
+++ b/packages/default.nix
@@ -1,33 +1,37 @@
 {
   final,
   prev,
-}:
-let
+}: let
   # Shared helper function to fetch from GitHub using JSON version files
   fetchfromGitHubJSONFile = path: prev.fetchFromGitHub (builtins.fromJSON (builtins.readFile path));
-  
+
   # Reference to the versions directory at the repo root
   versionsDir = ../versions;
-  
+
   # Common arguments passed to package modules that don't need 'final'
   baseArgs = {
     inherit prev fetchfromGitHubJSONFile versionsDir;
   };
-  
+
   # Arguments for packages that need access to 'final' (for cross-package dependencies)
-  argsWithFinal = baseArgs // {
-    inherit final;
-  };
+  argsWithFinal =
+    baseArgs
+    // {
+      inherit final;
+    };
 in {
   ## F
   fwildclusterboot = import ./f/fwildclusterboot.nix argsWithFinal;
-  
+
   ## H
   httpgd = import ./h/httpgd.nix baseArgs;
-  
+
+  ## J
+  jgd = import ./j/jgd.nix (baseArgs // {lib = prev.lib;});
+
   ## M
   musicMetadata = import ./m/musicMetadata.nix baseArgs;
-  
+
   ## S
   summclust = import ./s/summclust.nix baseArgs;
   synthdid = import ./s/synthdid.nix baseArgs;
diff --git a/packages/j/jgd.nix b/packages/j/jgd.nix
new file mode 100644
index 0000000..46b2dcd
--- /dev/null
+++ b/packages/j/jgd.nix
@@ -0,0 +1,25 @@
+{
+  lib,
+  prev,
+  fetchfromGitHubJSONFile,
+  versionsDir,
+}: let
+  repoSrc = fetchfromGitHubJSONFile "${versionsDir}/jgd.json";
+
+  rPkgSrc = lib.cleanSourceWith {
+    src = repoSrc;
+    filter = path: type: let
+      p = toString path;
+    in
+      # keep r-pkg/ and everything under it
+      (lib.hasPrefix (toString repoSrc + "/r-pkg") p);
+  };
+in
+  prev.rPackages.buildRPackage {
+    name = "jgd";
+    src = rPkgSrc;
+    sourceRoot = "source/r-pkg";
+    nativeBuildInputs = [
+      prev.pkg-config
+    ];
+  }
diff --git a/test/test.R b/test/test.R
index 77c0a61..864884d 100644
--- a/test/test.R
+++ b/test/test.R
@@ -1,13 +1,17 @@
 cat("Testing\n")
+cat("\n============================================================ jgd =========================================================================\n")
+library(jgd)
+jgd()
+
 cat("\n============================================================ fwildclusterboot ============================================================\n")
 library(fwildclusterboot)
 data(voters)
 lm_fit <- lm(
-  proposition_vote ~ treatment + ideology1 + log_income + Q1_immigration , 
+  proposition_vote ~ treatment + ideology1 + log_income + Q1_immigration ,
   data = voters
 )
 boot_lm <- boottest(
-  lm_fit, 
+  lm_fit,
   clustid = "group_id1",
   param = "treatment",
   B = 999
@@ -21,7 +25,7 @@ boot_lmjl <- boottest(
 )
 #setBoottest_engine("WildBootTests.jl")
 boot_lmjl2 <- boottest(
-  lm_fit, 
+  lm_fit,
   clustid = "group_id1",
   param = "treatment",
   B = 999
diff --git a/versions/default.nix b/versions/default.nix
index faa6d1a..62fc86a 100644
--- a/versions/default.nix
+++ b/versions/default.nix
@@ -1,5 +1,6 @@
 pkgs: ''
   pg=${pkgs.nix-prefetch-github}/bin/nix-prefetch-github
+  $pg --json grantmcdermott jgd > versions/jgd.json
   $pg --json hannesdatta musicMetadata > versions/musicMetadata.json
   $pg --json nx10 httpgd > versions/httpgd.json
   $pg --json s3alfisc fwildclusterboot > versions/fwildclusterboot.json
diff --git a/versions/jgd.json b/versions/jgd.json
new file mode 100644
index 0000000..9ac93b2
--- /dev/null
+++ b/versions/jgd.json
@@ -0,0 +1,6 @@
+{
+    "owner": "grantmcdermott",
+    "repo": "jgd",
+    "rev": "ec39bb7f9cf56727d4c47990bca02cd3256efcfc",
+    "hash": "sha256-ceJUPVRPZMwIeth7gfv8ULXAEzeQ2KRoqEhtp5rIGrw="
+}