diff --git a/flake.nix b/flake.nix
--- a/flake.nix
+++ b/flake.nix
@@ -13,6 +13,7 @@
       localOverlay = import ./nix/overlay.nix;
       overlays = [
         localOverlay
+        (_: _: { commSrc = toString self; })
       ];
 
       # Since we build for many systems (e.g. aarch64, x86_64-linux), we
diff --git a/nix/blob.nix b/nix/blob.nix
new file mode 100644
--- /dev/null
+++ b/nix/blob.nix
@@ -0,0 +1,43 @@
+{ stdenv
+, lib
+, rustPlatform
+, fetchFromGitHub
+, commSrc
+, protobuf_3_15_cmake
+, dockerTools
+, darwin
+}:
+
+let
+  blob = rustPlatform.buildRustPackage rec {
+    pname = "blob";
+    version = "0.0.1";
+
+    src = commSrc;
+
+    prePatch = "cd services/blob";
+
+    cargoLock.lockFile = ../services/blob/Cargo.lock;
+
+    nativeBuildInputs = [
+      protobuf_3_15_cmake
+    ];
+
+    buildInputs = lib.optionals stdenv.isDarwin [
+      darwin.apple_sdk.frameworks.Security
+      darwin.libiconv
+    ];
+
+    passthru.dockerImage = dockerTools.buildImage {
+      name = "comm-blob";
+      tag = "latest";
+      contents = [ blob ];
+      config.Cmd = [ "/bin/blob" ];
+    };
+
+    meta = with lib; {
+      license = licenses.bsd3;
+    };
+  };
+in
+  blob
diff --git a/nix/overlay.nix b/nix/overlay.nix
--- a/nix/overlay.nix
+++ b/nix/overlay.nix
@@ -49,6 +49,8 @@
     nativeBuildInputs = (o.nativeBuildInputs or []) ++ [ prev.cmake ];
   });
 
+  comm-blob = final.callPackage ./blob.nix { };
+
   protobuf_3_15_cmake = prev.callPackage ./protobuf_3_15.nix { };
 
   devShells.default = final.callPackage ./dev-shell.nix { };