Add Nix development environment

.envrc

@@ -0,0 +1,37 @@
+# Direnv setup for a dev environment with Nix.
+# See ./nix/README.md for more info.
+#
+# If you'd like to use your own direnv file, you can
+# stop git from tracking this file in your work tree and
+# then customize it as you please.
+#
+# To stop tracking this file:
+# > git update-index --skip-worktree .envrc
+# To begin tracking again:
+# > git update-index --no-skip-worktree .envrc
+#
+# If instead of completely ignoring this project wide .envrc file
+# you'd like to insert your own environment customizations, then you
+# can create an .envrc.local file that will be loaded.
+
+
+# Minimizes the amount of log output coming from direnv
+export DIRENV_LOG_FORMAT=
+
+flake_dir=./nix
+
+if type use_flake &>/dev/null; then
+  if type watch_file &>/dev/null; then
+    while IFS= read -r f; do
+      watch_file "$flake_dir/${f#./}"
+    done <<< "$(cd "$flake_dir" && git ls-files)"
+  fi
+
+  use flake "$flake_dir#dev"
+else
+  >&2 printf '\n!! Please install Nix to use this direnv config\n\n'
+  exit 1
+fi
+
+# Load the user's .envrc.local file if it exists
+source_env_if_exists .envrc.local

.gitignore

@@ -1,5 +1,8 @@
 .env
 
+.direnv/
+.envrc.local
+
 .DS_Store
 .vscode/
 

nix/README.md

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+# Nix
+
+This directory contains the Nix configuration for the render-mcp-server
+development environment. From the repository root, run `direnv allow` or
+`nix develop ./nix#dev` to enter the shell.
+
+
+## Upgrading Nix Packages
+
+### Performing the upgrade
+
+To upgrade nix packages run:
+```console
+$ nix flake update
+```
+
+This will update all inputs.
+
+### Test that things continue to work
+
+1. Open a shell at the root of this repository.
+2. Build the environment and perform some tests:
+   ```console
+   $ nix develop path:nix#dev --command go test ./...
+   ```

nix/flake.nix

@@ -0,0 +1,19 @@
+{
+  description = "render-mcp-server";
+
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, flake-utils }:
+    flake-utils.lib.eachDefaultSystem (system: {
+      devShells = import ./shells.nix {
+        pkgs = import nixpkgs {
+          inherit system;
+          config.allowUnfree = true;
+          overlays = import ./overlays;
+        };
+      };
+    });
+}

nix/overlays/default.nix

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+[
+  (self: super:
+    {
+      mkNiceShell = self.callPackage ./mkNiceShell.nix { };
+    }
+  )
+]

nix/overlays/mkNiceShell.nix

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+# A helper to make a more user friendly shell. Regular Nix shells
+# export a ton of unnecessary environment variables. Shells created with
+# this helper are much more clean.
+#
+# This is based off of the following files:
+# - https://github.com/numtide/devshell/
+#   blob/3e0e60ab37cd0bf7ab59888f5c32499d851edb47/nix/mkNakedShell.nix
+# - https://github.com/thenonameguy/devenv/
+#   blob/4717da802b1868318ab60758c244c4b37774f426/src/modules/mkNakedShell.nix
+#
+# Consequently, this code is goverened by the MIT license:
+# -----------------------------------------------------------------------------
+# MIT License
+#
+# Copyright (c) 2021 Numtide and contributors
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+# -----------------------------------------------------------------------------
+
+{ pkgs, system, ... }:
+let
+  inherit (pkgs) bashInteractive coreutils lib writeTextFile;
+
+  bashPath = "${bashInteractive}/bin/bash";
+  stdenv = writeTextFile {
+    name = "naked-stdenv";
+    destination = "/setup";
+    text = ''
+      # Fix for `nix develop`
+      : ''${outputs:=out}
+
+      runHook() {
+        eval "$shellHook"
+        unset runHook
+      }
+    '';
+  };
+in
+
+{ name ? "nice-shell"
+, shellHook ? ""
+, envVars ? { }
+, profilePackages ? [ ]
+, meta ? { }
+, passthru ? { }
+}:
+let
+
+  maybeEscape = value:
+    let
+      str = toString value;
+    in
+    if (builtins.match ''".*"'' str != null)
+    then str else lib.escapeShellArg str;
+
+  exportEnvVars =
+    envVars: builtins.concatStringsSep "\n" (
+      lib.mapAttrsToList
+        (name: value: "export ${name}=${maybeEscape value}")
+        envVars);
+
+  profile = pkgs.buildEnv {
+    name = "${name}-profile";
+    paths = builtins.concatMap
+      (p: builtins.map (o: lib.getOutput o p) p.outputs)
+      profilePackages;
+    ignoreCollisions = true;
+  };
+
+in
+(derivation {
+  inherit name;
+  system = pkgs.stdenv.hostPlatform.system;
+
+  # `nix develop` actually checks and uses builder. And it must be bash.
+  builder = bashPath;
+
+  # Bring in the dependencies on `nix-build`
+  args = [ "-ec" "${coreutils}/bin/ln -s ${profile} $out; exit 0" ];
+
+  # $stdenv/setup is loaded by nix-shell during startup.
+  # https://github.com/nixos/nix/blob/377345e26f1ac4bbc87bb21debcc52a1d03230aa/src/nix-build/nix-build.cc#L429-L432
+  inherit stdenv;
+
+  # The shellHook is loaded directly by `nix develop`. But nix-shell
+  # requires that other trampoline.
+  shellHook = ''
+    # Remove all the unnecessary noise that is set by the build env
+    unset NIX_BUILD_TOP NIX_BUILD_CORES NIX_STORE
+    unset TEMP TEMPDIR TMP TMPDIR
+    # $name variable is preserved to keep it compatible with pure shell https://github.com/sindresorhus/pure/blob/47c0c881f0e7cfdb5eaccd335f52ad17b897c060/pure.zsh#L235
+    unset builder out shellHook stdenv system
+    # Flakes stuff
+    unset dontAddDisableDepTrack outputs
+
+    # For `nix develop`. We get /noshell on Linux and /sbin/nologin on macOS.
+    if [[ "$SHELL" == "/noshell" || "$SHELL" == "/sbin/nologin" ]]; then
+      export SHELL=${bashPath}
+    fi
+
+    # add the profile packages to path
+    export PATH="${profile}/bin:$PATH"
+
+    # prepend common compilation lookup paths
+    export PKG_CONFIG_PATH="${profile}/lib/pkgconfig:$PKG_CONFIG_PATH"
+    export LD_LIBRARY_PATH="${profile}/lib:$LD_LIBRARY_PATH"
+    export LIBRARY_PATH="${profile}/lib:$LIBRARY_PATH"
+    export C_INCLUDE_PATH="${profile}/include:$C_INCLUDE_PATH"
+
+    # shell completions and default data dirs
+    export XDG_DATA_DIRS="${profile}/share:$XDG_DATA_DIRS"
+    export XDG_CONFIG_DIRS="${profile}/etc/xdg:$XDG_CONFIG_DIRS"
+
+    ${exportEnvVars envVars}
+
+    ${shellHook}
+  '';
+}) // { inherit meta passthru; } // passthru

nix/shells.nix

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+{ pkgs, ... }:
+{
+  dev = pkgs.mkNiceShell {
+    envVars = {
+      RENDER_MCP_SERVER_PATH = ''"$PWD"'';
+    };
+
+    profilePackages = with pkgs; [
+      # Golang
+      go_1_26
+      goreleaser
+
+      # Basic unix tools
+      coreutils
+      findutils
+    ];
+  };
+}