feat(ghostty): draw face shader based on herdr AI state

.serena/memories/core.md

@@ -4,22 +4,24 @@ nix-darwin system configuration flake for macOS (aarch64-darwin). Manages two ma
 - `maclop` — personal laptop, username: `derangga`
 - `worklop` — work laptop, username: `sociolla`
 
+Both hosts currently set `terminal = "ghostty"` in `flake.nix`.
+
 ## Entry Points
-- `flake.nix` — defines `darwinConfigurations` for both hosts via `mkDarwinConfig`
-- `darwin/configuration.nix` — system-level packages, fonts, defaults
-- `home/home.nix` — home-manager entry, imports `modules/default.nix`
-- `modules/default.nix` — root home-manager module, imports all sub-modules + `hosts/${hostname}.nix`
+- `flake.nix` — defines `darwinConfigurations` for both hosts via `mkDarwinConfig { hostname, username, terminal }`
+- `darwin/configuration.nix` — system-level packages, fonts, defaults; imports `darwin/homebrew` + `darwin/terminal.nix`
+- `modules/default.nix` — home-manager entry point (imported directly via `home-manager.users.${username} = import ./modules;` in `flake.nix`, no separate `home/home.nix`)
 
-## Key Module Directories
-- `modules/aerospace/` — window manager
-- `modules/catppuccin/` — theme (flavor: macchiato)
-- `modules/git/` — git config (hostname-conditional user.name)
-- `modules/llm-agents/` — AI tools (claude-code, opencode, beads, rtk, serena) via flake inputs
-- `modules/nixvim/` — Neovim via nixvim flake (plugins, keymaps, autocmds, options)
-- `modules/presenterm/` — presentation tool + mermaid-cli
-- `modules/sketchybar/` — menu bar, Lua-based config
-- `modules/starship/` — shell prompt (nosymbol + powerline variants)
-- `modules/terminal/` — Ghostty + Kitty terminal configs, GLSL shaders
-- `modules/hosts/` — host-specific home-manager config
+## Key Module Directories (modules/)
+- `aerospace/` — window manager
+- `catppuccin/` — theme (flavor: macchiato), one `catppuccin.<app>.enable` line per themed program
+- `ghost/` — Ghostty face shader driven by herdr AI state (background in the separate Claude auto-memory system's `ghost-in-the-machine` note, not a Serena memory)
+- `git/` — git config (hostname-conditional user.name)
+- `llm-agents/` — AI tools (claude-code, opencode, beads, beads-viewer, gitnexus, herdr, hunk, rtk, serena, fff-mcp) via flake inputs
+- `nixvim/` — Neovim via nixvim flake (plugins/, docs/, autocmds.nix, keymaps.nix, options.nix) — NOT LazyVim
+- `presenterm/` — presentation tool + mermaid-cli
+- `sketchybar/` — menu bar, Lua-based config (imported as `./sketchybar/config.nix`)
+- `starship/` — shell prompt: `no-version.nix` (active, imported in modules/default.nix) + `powerline.nix` (alternate, unused)
+- `terminal/` — Ghostty + Kitty terminal configs (`ghostty.nix`, `kitty.nix`, `options.nix`, `shaders/`), selected via the `terminal` specialArg
+- `hosts/` — host-specific home-manager config (`maclop.nix`, `worklop.nix`), imported as `./hosts/${hostname}.nix`
 
-See `mem:tech_stack` for flake inputs. See `mem:conventions` for code style. See `mem:suggested_commands` for CLI usage. See `mem:task_completion` for task checklist.
+See `mem:tech_stack` for flake inputs and packages. See `mem:conventions` for code style. See `mem:suggested_commands` for CLI usage. See `mem:task_completion` for task checklist.

.serena/memories/project_structure.md

@@ -4,7 +4,7 @@
 nix/
 ├── flake.nix                      # Entry point; defines maclop + worklop darwinConfigurations
 ├── flake.lock
-├── home/home.nix                  # home-manager entry; imports modules/default.nix
+├── README.md                      # User-facing docs (app table, usage, config steps)
 ├── darwin/
 │   ├── configuration.nix          # System-level config (packages, fonts, defaults)
 │   ├── terminal.nix               # Terminal-related system config
@@ -15,30 +15,33 @@ nix/
 │           └── worklop.nix        # Work machine Homebrew casks/formulae
 └── modules/
     ├── default.nix                # Root home-manager module; imports all sub-modules + host config
-    ├── aerospace/config.nix       # Aerospace window manager
-    ├── catppuccin/config.nix      # Catppuccin theme settings
-    ├── git/config.nix             # Git config (per-hostname user.name)
-    ├── neovim/config.nix          # Neovim (LazyVim-based)
-    │   └── lazyvim/               # LazyVim Lua config (plugins, keymaps, etc.)
-    ├── presenterm/config.nix      # Presenterm + mermaid-cli; config.yaml + puppeteer.json
-    ├── sketchybar/config.nix      # Sketchybar menu bar (Lua-based config)
-    │   └── lua/                   # Full Lua sketchybar config (items, widgets, helpers)
+    ├── aerospace/                 # Aerospace window manager
+    ├── catppuccin/default.nix     # Catppuccin theme settings (per-app enable flags)
+    ├── ghost/                     # Ghostty face shader driven by herdr AI state; script/ (Go) + .glsl shader
+    ├── git/                       # Git config (per-hostname user.name)
+    ├── llm-agents/default.nix     # Claude Code, OpenCode, Beads, RTK, Serena, herdr, hunk, fff-mcp
+    ├── nixvim/                    # Neovim via nixvim flake (NOT LazyVim)
+    │   ├── plugins/                 # Plugin configurations (completion, lsp, ui, etc.)
+    │   └── docs/                    # Neovim docs
+    ├── presenterm/                 # Presenterm + mermaid-cli; config.yaml + puppeteer.json
+    ├── sketchybar/                 # Sketchybar menu bar (Lua-based config), config.nix + lua/
     ├── starship/
-    │   ├── nosymbol.nix           # Starship prompt (no-symbol variant)
-    │   └── powerline.nix          # Starship prompt (powerline variant)
+    │   ├── no-version.nix          # Starship prompt (active variant, imported in modules/default.nix)
+    │   └── powerline.nix           # Starship prompt (alternate variant, unused)
     ├── terminal/
-    │   ├── default.nix            # Terminal module entry
-    │   ├── ghostty.nix            # Ghostty terminal config
-    │   ├── kitty.nix              # Kitty terminal config
-    │   ├── options.nix            # Terminal options/selector
-    │   └── shaders/               # GLSL shaders for terminal eye candy
+    │   ├── default.nix             # Terminal module entry
+    │   ├── ghostty.nix             # Ghostty terminal config
+    │   ├── kitty.nix               # Kitty terminal config
+    │   ├── options.nix             # Terminal options/selector (driven by `terminal` specialArg)
+    │   └── shaders/                # GLSL shaders for terminal eye candy
     └── hosts/
-        ├── maclop.nix             # Personal: flutter, cocoapods, vscode, OBS catppuccin
-        └── worklop.nix            # Work: pm2
+        ├── maclop.nix              # Personal host overrides
+        └── worklop.nix             # Work host overrides
 ```
 
 ## modules/default.nix Programs (shared across hosts)
-bat, btop, claude-code, eza, fzf, gh, gh-dash, lazygit, opencode, tmux, yazi, zed-editor, zoxide, zsh (Oh-My-Zsh)
+atuin, bat, btop, eza, gh, gh-dash, lazygit, tmux, vscode, yazi, zoxide, zsh (Oh-My-Zsh)
+Plus imports: aerospace, catppuccin, ghost, git, llm-agents, terminal, nixvim, presenterm, starship/no-version.nix, sketchybar/config.nix, hosts/${hostname}.nix
 
 ## System Packages (darwin/configuration.nix)
-bun, cargo, fnm, ffmpeg, gnupg, go, mkalias, nixd, pnpm, rustc, rust-analyzer, tree, uv
+ffmpeg, gnupg, mkalias, tree

.serena/memories/tech_stack.md

@@ -3,23 +3,26 @@
 ## Flake Inputs
 - `nixpkgs` → `nixpkgs-unstable`
 - `nix-darwin` → master branch
+- `nix-homebrew` — Homebrew integration
 - `home-manager` (follows nixpkgs)
 - `catppuccin/nix` (follows nixpkgs)
-- `nix-homebrew` — Homebrew integration
-- `nixvim` — Neovim configured entirely in Nix
-- `fff-nvim` — Neovim plugin (custom flake input)
-- `llm-agents` → `github:numtide/llm-agents.nix` — provides claude-code, opencode, beads, rtk
-- `serena` → `git+https://github.com/oraios/serena` — MCP server for semantic code tools
+- `nixvim` — Neovim configured entirely in Nix (follows nixpkgs)
+- `fff-nvim` — `github:dmtrKovalenko/fff.nvim`, only its `fff-mcp` package is used (follows nixpkgs)
+- `llm-agents` → `github:numtide/llm-agents.nix` (follows nixpkgs)
+- `serena` → `git+https://github.com/oraios/serena` (follows nixpkgs)
 
 ## System Packages (darwin/configuration.nix)
-bun, cargo, fnm, ffmpeg, gnupg, go, mkalias, nixd, pnpm, rustc, rust-analyzer, tree, uv
+ffmpeg, gnupg, mkalias, tree
+(bun, cargo, fnm, go, orbstack, rust-analyzer, rustc live in `modules/default.nix` `home.packages`, not here)
 
 ## Home-manager Programs (modules/default.nix, shared)
-bat, btop, eza, fzf, gh, gh-dash, lazygit, tmux, yazi, zed-editor (package=null), zoxide, zsh (Oh-My-Zsh)
+atuin (replaced fzf — shell history/Ctrl-R search), bat, btop, eza, gh, gh-dash, lazygit, tmux, vscode, yazi, zoxide, zsh (Oh-My-Zsh, `git` plugin only)
+Plus `services.jankyborders` (window border styling).
 
 ## AI/LLM Tools (modules/llm-agents/default.nix)
-Sourced from `llm-agents.packages.${system}` and `serena.packages.${system}`:
-claude-code, opencode, beads, rtk, serena
+`home.packages` sourced from `llm-agents.packages.${system}` and `serena.packages.${system}`, plus `fff-nvim.packages.${system}.fff-mcp`:
+fff-mcp, beads, beads-viewer, claude-code, gitnexus, herdr, hunk, opencode, rtk, serena
+Also writes `xdg.configFile` for `herdr/config.toml` and `hunk/config.toml`, and two `home.activation` scripts that patch `~/.claude.json` (fff MCP entry) and append the fff-usage line to `~/.claude/CLAUDE.md`.
 
 ## Target Platform
 `aarch64-darwin` (Apple Silicon Macs)

README.md

@@ -48,7 +48,7 @@ All the following applications are managed via home-manager and will be configur
 ### Shell & Terminal
 | Application | Description |
 |---|---|
-| Zsh + Oh My Zsh | Shell with git and fzf plugins |
+| Zsh + Oh My Zsh | Shell with git plugin; Atuin powers history search (Ctrl-R) |
 | Starship | Cross-shell prompt |
 | Kitty | GPU-accelerated terminal |
 | Ghostty | Fast terminal emulator |
@@ -78,10 +78,10 @@ Sourced from [numtide/llm-agents.nix](https://github.com/numtide/llm-agents.nix)
 ### CLI Utilities
 | Application | Description |
 |---|---|
+| atuin | Shell history search (SQLite-backed, Ctrl-R) |
 | bat | `cat` clone with syntax highlighting |
 | btop | Resource monitor |
 | eza | Modern `ls` replacement |
-| fzf | Fuzzy finder |
 | yazi | Terminal file manager |
 | zoxide | Smarter `cd` with frecency-based navigation |
 | gh | GitHub CLI |

modules/default.nix

@@ -14,6 +14,7 @@
 
     ./aerospace
     ./catppuccin
+    ./ghost
     ./git
     ./llm-agents
     ./terminal

modules/ghost/NOTICE

@@ -0,0 +1,15 @@
+ghost-in-the-machine.glsl in this directory is vendored, unmodified, from
+pi-ghost-in-the-machine by Iury Souza:
+https://github.com/iurysza/pi-ghost-in-the-machine
+
+That shader is itself derived from claude-terminal-face by isoden:
+https://github.com/isoden/claude-terminal-face
+
+Both original works are distributed under the MIT License, as is this
+derivative. The FORCED_STATE and sidebar-placement constants are substituted at
+build time by ../ghost/default.nix rather than edited in place, so the vendored
+file matches upstream byte for byte.
+
+Everything else here is new: herdr socket subscription in place of both the Pi
+extension and the polling sidebar watcher, herdr's own agent_status as the
+state source in place of agent-side hooks, and Nix packaging.

modules/ghost/default.nix

@@ -0,0 +1,79 @@
+{
+  config,
+  lib,
+  pkgs,
+  terminal,
+  ...
+}:
+lib.mkIf (terminal == "ghostty") (
+  let
+    stateDir = "${config.home.homeDirectory}/.local/state/ghost-in-the-machine";
+
+    # Face placement. The shader centres the face inside herdr's sidebar, so
+    # sidebarCols must match herdr's own sidebar_width (see session.json) or the
+    # face drifts out over terminal text. cellWidth is upstream's value for
+    # their font; retune by eye with `ghost-watch idle`.
+    sidebarCols = 26;
+    cellWidth = 16;
+
+    variants = pkgs.runCommand "ghost-variants" { } ''
+      mkdir -p "$out"
+      for pair in idle:0 thinking:1 working:2 done:3 error:4; do
+        name="''${pair%%:*}"
+        forced="''${pair##*:}"
+        ${pkgs.gawk}/bin/awk \
+          -v forced="$forced" \
+          -v cols="${toString sidebarCols}" \
+          -v cell="${toString cellWidth}" '
+          $0 == "const int FORCED_STATE = -1;" {
+            print "const int FORCED_STATE = " forced ";"; next
+          }
+          /^const float SIDEBAR_COLS/ {
+            print "const float SIDEBAR_COLS = " cols ".0;"; next
+          }
+          /^const float SIDEBAR_CELL_WIDTH/ {
+            print "const float SIDEBAR_CELL_WIDTH = " cell ".0;"; next
+          }
+          { print }
+        ' ${./ghost-in-the-machine.glsl} > "$out/$name.glsl"
+      done
+      grep -q "FORCED_STATE = 2;" "$out/working.glsl" || {
+        echo "substitution missed FORCED_STATE; upstream shader changed" >&2
+        exit 1
+      }
+    '';
+
+    # Stdlib only, hence vendorHash = null -- no vendor dir, no network fetch.
+    ghostWatch = pkgs.buildGoModule {
+      pname = "ghost-watch";
+      version = "0";
+      src = ./script;
+      vendorHash = null;
+      # There are no go tests; the self-check is the check, and it is hermetic.
+      doCheck = false;
+      postInstall = "$out/bin/ghost-watch --selfcheck";
+    };
+  in
+  {
+    home.packages = [ ghostWatch ];
+
+    home.activation.ghostStateDir = lib.hm.dag.entryAfter [ "writeBoundary" ] ''
+      $DRY_RUN_CMD mkdir -p ${lib.escapeShellArg stateDir}
+    '';
+
+    launchd.agents.ghost-in-the-machine = {
+      enable = true;
+      config = {
+        ProgramArguments = [ "${ghostWatch}/bin/ghost-watch" ];
+        EnvironmentVariables = {
+          GHOST_VARIANTS = "${variants}";
+          GHOST_FRAGMENT = "${stateDir}/ghostty.conf";
+        };
+        KeepAlive = true;
+        RunAtLoad = true;
+        ProcessType = "Background";
+        StandardErrorPath = "${stateDir}/watch.log";
+      };
+    };
+  }
+)