feat(macos): native install path via Homebrew

install-macos.sh mirrors install.sh's split: every portable step - git pull,
venv, pip with the right overlay, npm build - stays in bin/sync.py, shared
with Linux and Windows. The script only does what sync.py cannot do for
itself on a bare Mac, which is install the Homebrew packages needed before a
Python exists to run sync.py with.

Two stages had to learn about darwin. ensure_exec_bits() keyed off
`os.name == "nt"`, which is false on macOS, so it ran the Linux path; and
requirements() had no darwin branch. linux_stage() now no-ops there, which is
what makes skipping the Ollama fetch correct rather than an omission:
bin/fetch-ollama.sh only ships a Linux x86-64 binary, and _ollama_bin() in
synapse/ollama_manager.py already prefers the bundled copy and falls back to
whatever `ollama` is on PATH. On macOS that is the brewed one, with Metal
acceleration and no flags needed.

The XFCE desktop branding is Linux-only and was already gated off macOS the
same way, so there is nothing to install for it here.

install-macos.sh joins the shell-parse list in bin/check.sh.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

CLAUDE.md

@@ -37,6 +37,17 @@ desktop shortcut runs and still works directly.
 ```
 This activates the `Promethean` venv and starts the Synapse backend on port 8000 (which also serves the built UI). It additionally starts a **Vite dev server** for frontend hot-reload — a Linux-dev convenience, unlike the single-process Windows/production path where the backend serves `dist/` alone. It does **not** start Ollama.
 
+**macOS (community-supported):**
+```bash
+./install-macos.sh   # one-time: Homebrew packages + venv + web build, via bin/sync.py
+./launch_nexus.sh     # same script as Linux - it's plain bash, no Linux-only calls
+```
+No bundled Ollama binary (Linux x86-64 only) and no XFCE desktop branding — both
+already no-op on macOS via `bin/sync.py`'s `linux_stage()`. Ollama is instead the
+Homebrew-installed native binary, picked up automatically because
+`OllamaManager` falls back to `ollama` on PATH when the bundled binary is
+absent; that gets full Metal GPU acceleration with no extra config.
+
 **Individual services via CLI:**
 ```bash
 # From nexus-core/ with Promethean venv active:
@@ -92,7 +103,7 @@ cd interface/web && npm run build
 ## Architecture
 
 ### Python venv
-All Python code runs inside `Promethean/` (a local venv). Always activate it before running backend commands: `source Promethean/bin/activate`. Dependencies are layered: `requirements-base.txt` holds the GPU-agnostic core (nothing in it needs a GPU or imports torch), and a thin overlay per platform sets the right PyTorch package index — `requirements-amd.txt` (ROCm), `requirements-nvidia.txt` (CUDA, generated by `bin/gen-nvidia-reqs.py`), or `requirements-windows.txt` (CPU-only, standalone). `bin/sync.py` (`requirements()`) selects NVIDIA, AMD, or CPU/Windows requirements from the host and installs that alone by default — fast, no multi-GB downloads.
+All Python code runs inside `Promethean/` (a local venv). Always activate it before running backend commands: `source Promethean/bin/activate`. Dependencies are layered: `requirements-base.txt` holds the GPU-agnostic core (nothing in it needs a GPU or imports torch), and a thin overlay per platform sets the right PyTorch package index — `requirements-amd.txt` (ROCm), `requirements-nvidia.txt` (CUDA, generated by `bin/gen-nvidia-reqs.py`), or `requirements-windows.txt` (CPU-only, standalone). macOS uses `requirements-base.txt` without an overlay because Ollama handles inference outside the venv. `bin/sync.py` (`requirements()`) selects the appropriate requirements for the host and installs that alone by default — fast, no multi-GB downloads.
 
 `requirements-ml.txt` is a separate, **opt-in** overlay for local ML inference (transformers/accelerate/bitsandbytes + torch/torchaudio/torchvision) — nothing in `synapse/` imports any of it; Ollama does all inference over HTTP. Only pull it in for local model work outside Ollama: `pip install -r requirements-amd.txt -r requirements-ml.txt` (or `-nvidia`, or alone for CPU-only torch). Not installed by `bin/sync.py`/the installers.
 

README.md

@@ -134,7 +134,8 @@ ncp web
 Python deps are layered: `requirements-base.txt` (GPU-agnostic core) plus one
 GPU overlay — `requirements-amd.txt` (ROCm) or `requirements-nvidia.txt` (CUDA).
 `requirements-windows.txt` is the standalone CPU-only runtime (no base overlay).
-`bin/sync.py` picks the right one for the host.
+macOS uses `requirements-base.txt` directly, no overlay — see the macOS section
+below. `bin/sync.py` picks the right one for the host.
 
 `./install.sh` is also the update path — re-run it any time to pull the latest
 and rebuild. `--check` dry-runs it; `--no-desktop` skips the XFCE panel/theme
@@ -172,10 +173,38 @@ The app opens at `:8000`; click **Start AI** to launch Ollama. The installer
 uses `requirements-windows.txt` (CPU-only, pure-Python — no ML stack, since Ollama
 does all inference over HTTP).
 
+### macOS
+
+Community-supported — no bundled Ollama binary or XFCE desktop branding (that
+stage is Linux/XFCE-only and already skips itself here), but the
+backend/frontend/Ollama stack itself runs natively, no VM or container needed.
+
+```bash
+# 1. Install Homebrew first if you don't have it: https://brew.sh
+
+# 2. Build everything: Homebrew packages (Python, Node, git, Ollama), venv,
+#    web UI, memory DB.
+./install-macos.sh
+
+# 3. Launch (memory :8001, backend :8000 — backend also serves the built UI)
+./launch_nexus.sh
+```
+
+Ollama here is the Homebrew-installed native binary, not the Linux-only bundled
+one — `OllamaManager` already falls back to `ollama` on PATH when
+`ollama/bin/ollama` doesn't exist, so **Start AI** in the sidebar (or `ollama
+serve` in a terminal) uses it with full Metal GPU acceleration automatically,
+no configuration needed.
+
+`./install-macos.sh` is also the update path, same idea as Linux — re-run it
+any time to pull the latest and rebuild; `--check` dry-runs it. It's a thin
+wrapper over `bin/sync.py restore`, the same code Linux and `ncp restore`
+(any platform) run.
+
 ### Individual services
 
 ```bash
-# Linux
+# Linux / macOS
 source Promethean/bin/activate
 
 uvicorn synapse.main:sio_app          --host 127.0.0.1 --port 8000 --reload   # backend (serves the UI too)
@@ -199,7 +228,7 @@ Nexus's dependencies out of the system Python. To add a package, activate it
 and `pip install` as usual:
 
 ```bash
-# Linux
+# Linux / macOS
 source Promethean/bin/activate
 pip install <package>
 ```
@@ -274,7 +303,9 @@ are the exception (YAML files in `data/playbooks/`). All paths are defined in
 - **Filesystem paths** — `synapse/nexus_config.py`
 - **Frontend API base URL** — `interface/web/src/config.js`
 - **Python deps** — `requirements-base.txt` + amd/nvidia GPU overlay;
-  `requirements-windows.txt` = standalone CPU runtime
+  `requirements-windows.txt` = standalone CPU runtime; macOS uses
+  `requirements-base.txt` with no overlay (Ollama, not this venv, does
+  inference — natively, with Metal)
 
 ## Issues and feature requests
 

bin/check.sh

@@ -40,7 +40,7 @@ else
 fi
 
 echo "== shell parse =="
-for f in scripts/install-termux.sh launch_nexus.sh management/nexus-cli.sh; do
+for f in scripts/install-termux.sh install-macos.sh launch_nexus.sh management/nexus-cli.sh; do
     [ -f "$f" ] && { bash -n "$f" || fail=1; }
 done
 

bin/sync.py

@@ -66,9 +66,11 @@ def ensure_exec_bits() -> None:
 
 
 def linux_stage(script: str, *args) -> None:
-    """Run one of the Linux-only bash stages. A no-op on Windows, where apt,
+    """Run one of the Linux-only bash stages. A no-op on Windows and macOS,
-    xfconf, plank and the rest have nothing to act on."""
+    where apt, xfconf, plank and the rest have nothing to act on. os.name is
-    if os.name == "nt":
+    'posix' on both Linux and macOS, so the Windows-only os.name check alone
+    doesn't exclude macOS - needs the explicit darwin check too."""
+    if os.name == "nt" or sys.platform == "darwin":
         return
     path = ROOT / "bin" / script
     bash = shutil.which("bash")
@@ -109,6 +111,13 @@ def requirements() -> str:
     """Pick the PyTorch overlay for this host."""
     if os.name == "nt":
         return "requirements-windows.txt"        # CPU / pure-Python, right for native Windows
+    if sys.platform == "darwin":
+        # No ROCm/CUDA overlay applies here, and none is needed: Ollama does
+        # all inference over HTTP (see requirements-ml.txt), and on macOS
+        # that's a natively-installed, Metal-accelerated Ollama binary
+        # (OllamaManager falls back to it on PATH - see synapse/ollama_manager.py),
+        # entirely outside this venv.
+        return "requirements-base.txt"
     if shutil.which("nvidia-smi"):
         return "requirements-nvidia.txt"
     lspci = shutil.which("lspci")

install-macos.sh

@@ -0,0 +1,43 @@
+#!/bin/bash
+# NexusOS installer, macOS. One painless command:
+#
+#   git clone <repo> nexus-core && cd nexus-core && ./install-macos.sh
+#
+# Mirrors install.sh's philosophy: every portable step - git pull, venv, pip
+# with the right overlay, npm build - lives in bin/sync.py, shared with Linux
+# and Windows. This script only does what sync.py can't do for itself on a
+# bare Mac: install the Homebrew packages needed before Python even exists to
+# run sync.py with. Re-run any time to update; --check dry-runs it.
+#
+# Ollama itself is *not* fetched here - bin/fetch-ollama.sh only ships a Linux
+# x86-64 binary, and linux_stage() in bin/sync.py already no-ops on macOS, so
+# that stage is skipped entirely. The Homebrew `ollama` installed below is
+# picked up automatically instead: synapse/ollama_manager.py prefers the
+# bundled Linux binary and falls back to whatever `ollama` it finds on PATH,
+# which on macOS is this one - with full Metal GPU acceleration, no flags
+# needed. The XFCE desktop branding (theme/panel/splash) is Linux-only and
+# already gated off macOS the same way; nothing to install for it here.
+set -euo pipefail
+cd "$(dirname "$0")"
+
+if ! command -v brew >/dev/null; then
+    echo "Homebrew is required (it installs Python/Node/git/Ollama)." >&2
+    echo "Install it, then re-run this script:  https://brew.sh" >&2
+    exit 1
+fi
+
+echo "Installing/checking system packages (python@3.12, node, git, ollama)..."
+brew install python@3.12 node git ollama
+
+py="$(brew --prefix python@3.12)/bin/python3.12"
+if [ ! -x "$py" ]; then
+    echo "python3.12 not found at $py after brew install - check 'brew doctor'." >&2
+    exit 1
+fi
+
+# Prefer the venv interpreter once it exists, same as install.sh; the brewed
+# interpreter above is only the bootstrap case on a fresh clone. sync.py is
+# stdlib-only either way.
+[ -x "Promethean/bin/python" ] && py="Promethean/bin/python"
+
+exec "$py" bin/sync.py restore "$@"