Enable OpenCode and add its configuration

Enable the OpenCode service on both desktop and laptop hosts.
Import the opencode module into the home configuration and provide
settings, plugins, extra packages, and skill definitions for full
functionality.

modules/home/codex/default.nix

@@ -10,6 +10,9 @@
     enable = true;
     package = pkgs.codex;
     mutableSettings = true;
+    # skills = {
+    #   beads = "${pkgs.beads.src}/plugins/beads/skills/beads";
+    # };
   };
 
   imports = [

modules/home/default.nix

@@ -11,6 +11,7 @@ _: {
     ./noctalia
     # ./noctalia-shell
     ./obsidian
+    ./opencode
     ./scripts
     ./vscodium
     ./xdg
@@ -35,7 +36,6 @@ _: {
     ./obs-studio.nix
     ./ollama.nix
     ./onlyoffice.nix
-    ./opencode.nix
     ./prismlauncher.nix
     ./qt.nix
     ./skills.nix

modules/home/opencode/default.nix

@@ -9,5 +9,15 @@
   config.programs.opencode = lib.mkIf config.opencode.enable {
     enable = true;
     package = pkgs.opencode;
+    validateFiles = {
+      config = true;
+      tui = true;
+    };
   };
+
+  imports = [
+    ./settings
+    ./skills
+    ./extra-packages.nix
+  ];
 }

modules/home/opencode/extra-packages.nix

@@ -0,0 +1,12 @@
+{pkgs, ...}: {
+  programs.opencode.extraPackages = with pkgs; [
+    uv
+    ruff
+    biome
+    bun
+    beads
+    rust-analyzer
+    alejandra
+    docker
+  ];
+}

modules/home/opencode/settings/default.nix

@@ -0,0 +1,16 @@
+_: {
+  programs.opencode.settings = {
+    autoupdate = false;
+    compaction = {
+      auto = true;
+      prune = false;
+    };
+  };
+
+  imports = [
+    ./formatter.nix
+    ./model.nix
+    ./permission.nix
+    ./plugin.nix
+  ];
+}

modules/home/opencode/settings/formatter.nix

@@ -0,0 +1,35 @@
+_: {
+  programs.opencode.settings.formatter = {
+    gofmt.disabled = true;
+    mix.disabled = true;
+    prettier.disabled = true;
+    zig.disabled = true;
+    clang-format.disabled = true;
+    ktlint.disabled = true;
+    rubocop.disabled = true;
+    standardrb.disabled = true;
+    htmlbeautifier.disabled = true;
+    air.disabled = true;
+    dart.disabled = true;
+    dfmt.disabled = true;
+    ocamlformat.disabled = true;
+    terraform.disabled = true;
+    gleam.disabled = true;
+    nixfmt.disabled = true;
+    shfmt.disabled = true;
+    pint.disabled = true;
+    oxfmt.disabled = true;
+    ormolu.disabled = true;
+
+    # biome = {};
+    # ruff = {};
+    # rustfmt = {};
+    # cargo = {};
+    # uv = {};
+
+    alejandra = {
+      command = ["alejandra" "$FILE"];
+      extensions = [".nix"];
+    };
+  };
+}

modules/home/opencode/settings/model.nix

@@ -0,0 +1,7 @@
+_: {
+  programs.opencode.settings = {
+    model = "cerebras/gpt-oss-120b";
+    small_model = "cerebras/qwen-3.8-27b";
+    enabled_providers = ["cerebras"];
+  };
+}

modules/home/opencode/settings/permission.nix

@@ -0,0 +1,13 @@
+_: {
+  programs.opencode.settings.permission = {
+    bash = "allow";
+    edit = "allow";
+    grep = "allow";
+    glob = "allow";
+    lsp = "ask";
+    skill = "allow";
+    webfetch = "ask";
+    websearch = "ask";
+    question = "allow";
+  };
+}

modules/home/opencode/settings/plugin.nix

@@ -0,0 +1,7 @@
+_: {
+  programs.opencode.settings.plugin = [
+    "@dietrichgebert/ponytail"
+    "context-mode"
+    "opencode-mem"
+  ];
+}

modules/home/opencode/skills/default.nix

@@ -0,0 +1,5 @@
+_: {
+  imports = [
+    ./understand-anything.nix
+  ];
+}

modules/home/opencode/skills/understand-anything.nix

@@ -0,0 +1,22 @@
+{pkgs, ...}: let
+  understand-anything-src = pkgs.fetchFromGitHub {
+    name = "understand-anything";
+    owner = "Egonex-AI";
+    repo = "Understand-Anything";
+    tag = "v2.9.0";
+    sha256 = "sha256-nECfbp0vyFZRZX0Zg2s4ga/kYSCihJxYt9lxUHLGmFA=";
+  };
+  understand-anything = "${understand-anything-src}/understand-anything-plugin/skills";
+in {
+  programs.opencode.skills = {
+    understand = "${understand-anything}/understand";
+    understand-chat = "${understand-anything}/understand-chat";
+    understand-dashboard = "${understand-anything}/understand-dashboard";
+    understand-diff = "${understand-anything}/understand-diff";
+    understand-domain = "${understand-anything}/understand-domain";
+    understand-explain = "${understand-anything}/understand-explain";
+    understand-figma = "${understand-anything}/understand-figma";
+    understand-knowledge = "${understand-anything}/understand-knowledge";
+    understand-onboard = "${understand-anything}/understand-onboard";
+  };
+}