Initial commit: MCP server packages for Nix

- Add flake structure with overlay and packages exports
- Add manim-mcp-server as first packaged MCP server
- Add README.org with usage instructions and package templates
- Add packages/default.nix as package aggregator
- Add overlays/default.nix for nixpkgs integration

packages/default.nix

@@ -0,0 +1,16 @@
+# MCP Server Packages
+#
+# This file aggregates all MCP server packages in this repository.
+# To add a new package:
+#   1. Create a directory: packages/<package-name>/
+#   2. Create package.nix in that directory
+#   3. Add an entry below using callPackage
+#
+{ pkgs }:
+
+{
+  manim-mcp-server = pkgs.callPackage ./manim-mcp-server/package.nix { };
+
+  # Add new packages here:
+  # example-mcp-server = pkgs.callPackage ./example-mcp-server/package.nix { };
+}

packages/manim-mcp-server/package.nix

@@ -0,0 +1,54 @@
+{
+  lib,
+  stdenv,
+  fetchFromGitHub,
+  makeWrapper,
+  python3,
+  manim,
+}:
+
+let
+  python = python3.withPackages (
+    ps: with ps; [
+      mcp
+      fastmcp
+    ]
+  );
+in
+stdenv.mkDerivation rec {
+  pname = "manim-mcp-server";
+  version = "0.0.1-unstable";
+
+  src = fetchFromGitHub {
+    owner = "abhiemj";
+    repo = "manim-mcp-server";
+    rev = "da23214426a56ce3ba4da39b0718d64cf97cd23c";
+    hash = "sha256-orR3CtFiSucErPJzIF0Si4s16LH1d+ZhyUKo6PC966I=";
+  };
+
+  nativeBuildInputs = [ makeWrapper ];
+
+  dontBuild = true;
+
+  installPhase = ''
+    runHook preInstall
+
+    mkdir -p $out/bin $out/lib/manim-mcp-server
+    cp src/manim_server.py $out/lib/manim-mcp-server/
+
+    makeWrapper ${python}/bin/python $out/bin/manim-mcp-server \
+      --add-flags "$out/lib/manim-mcp-server/manim_server.py" \
+      --set MANIM_EXECUTABLE "${manim}/bin/manim"
+
+    runHook postInstall
+  '';
+
+  meta = with lib; {
+    description = "MCP server that executes Manim animation code and returns generated videos";
+    homepage = "https://github.com/abhiemj/manim-mcp-server";
+    license = licenses.mit;
+    maintainers = [ ];
+    mainProgram = "manim-mcp-server";
+    platforms = platforms.all;
+  };
+}