diff --git a/flake.nix b/flake.nix
index 215d52f..9129132 100644
--- a/flake.nix
+++ b/flake.nix
@@ -27,27 +27,10 @@
         };
       };
       devShells = {
-        default = pkgs.mkShell {
-          packages = with pkgs; [
-            snakemake
-            gawk
-            gnused
-            nickel
-            graphviz
-	    # TODO separate into several shells
-            (python3.withPackages (ps: with ps; [
-              requests
-	      kapkgs.execo
-            ]))
-            #(rWrapper.override { packages = with rPackages; [ tidyverse reshape2 ]; })
-          ];
-        };
-        latex = pkgs.mkShell {
-          packages = with pkgs; [
-            texliveFull
-            rubber
-          ];
-        };
+        default  = import ./workflow/envs/snakemake.nix { inherit pkgs kapkgs; };
+        nickel   = import ./workflow/envs/nickel.nix { inherit pkgs kapkgs; };
+        latex    = import ./workflow/envs/latex.nix { inherit pkgs kapkgs; };
+        analysis = import ./workflow/envs/analysis.nix { inherit pkgs kapkgs; };
       };
     });
 }
diff --git a/workflow/envs/analysis.nix b/workflow/envs/analysis.nix
new file mode 100644
index 0000000..cd864c6
--- /dev/null
+++ b/workflow/envs/analysis.nix
@@ -0,0 +1,12 @@
+{ pkgs, kapkgs }:
+
+pkgs.mkShell {
+  packages = with pkgs; [
+    (rWrapper.override {
+      packages = with rPackages; [
+        tidyverse
+        reshape2
+      ];
+    })
+  ];
+}
diff --git a/workflow/envs/latex.nix b/workflow/envs/latex.nix
new file mode 100644
index 0000000..e136ecd
--- /dev/null
+++ b/workflow/envs/latex.nix
@@ -0,0 +1,8 @@
+{ pkgs, kapkgs }:
+
+pkgs.mkShell {
+  packages = with pkgs; [
+    texliveFull
+    rubber
+  ];
+}
diff --git a/workflow/envs/nickel.nix b/workflow/envs/nickel.nix
new file mode 100644
index 0000000..a726eec
--- /dev/null
+++ b/workflow/envs/nickel.nix
@@ -0,0 +1,7 @@
+{ pkgs, kapkgs }:
+
+pkgs.mkShell {
+  packages = with pkgs; [
+    nickel
+  ];
+}
diff --git a/workflow/envs/snakemake.nix b/workflow/envs/snakemake.nix
new file mode 100644
index 0000000..e5791c7
--- /dev/null
+++ b/workflow/envs/snakemake.nix
@@ -0,0 +1,12 @@
+{ pkgs, kapkgs }:
+
+pkgs.mkShell {
+  packages = with pkgs; [
+    snakemake
+    gawk
+    gnused
+    (python3.withPackages (ps: with ps; [
+      kapkgs.execo 
+    ]))
+  ];
+}