docs: add AGENTS.md and update README with CPU/CUDA setup

AGENTS.md

@@ -0,0 +1,129 @@
+# VibePod — Agent Guide
+
+This file gives AI coding agents (Jules, Copilot, Claude Code, etc.) the context needed to work effectively on this repo without breaking the two-service setup.
+
+---
+
+## Project overview
+
+VibePod is a text-to-speech web app. It has two services that must both run for the app to work:
+
+| Service | Language | Entry point | Port |
+|---------|----------|-------------|------|
+| **server** | Python 3.10+ (FastAPI + VibeVoice) | `server/start.sh` | 8000 |
+| **web** | TypeScript (Next.js 15, React 19) | `pnpm --filter vibepod-web dev` | 3000 |
+
+The Next.js frontend proxies all model requests through its own API routes to the FastAPI server — it never calls the Python server directly from the browser.
+
+---
+
+## Environment (Jules sandbox)
+
+- **No GPU** — always use CPU mode (`pnpm dev:cpu` / `start.sh --cpu`)
+- Python venv lives at `server/.venv-cpu` — do **not** use `server/.venv`
+- The VibeVoice model (~1 GB) is pre-downloaded to `~/.cache/huggingface` during setup
+- Voice presets live at `server/voices/streaming_model/`
+- `server/uv.lock` is committed and must not be modified — if `uv sync` rewrites it, run `git checkout server/uv.lock`
+
+---
+
+## Running the app
+
+```bash
+# Full stack — CPU (correct for Jules)
+pnpm dev:cpu
+
+# Full stack — CUDA (local dev with GPU)
+pnpm dev
+
+# Individual services
+pnpm dev:server:cpu   # Python server, CPU only
+pnpm dev:server       # Python server, CUDA
+pnpm dev:web          # Next.js only
+
+# Production build
+pnpm build
+```
+
+---
+
+## Device selection
+
+The `--cpu` flag in `start.sh` sets `VIBEPOD_DEVICE=cpu` and uses a separate venv (`server/.venv-cpu`) so CUDA and CPU installs never conflict. `vibevoice_server.py` reads `VIBEPOD_DEVICE` at startup via `_resolve_device()` — do not remove or rename that function.
+
+| Env var | Values | Set by |
+|---------|--------|--------|
+| `VIBEPOD_DEVICE` | `cpu` \| `cuda` | `server/start.sh` |
+| `UV_PROJECT_ENVIRONMENT` | `.venv-cpu` \| `.venv` | `server/start.sh` |
+| `HF_TOKEN` | HuggingFace token | Jules secret / `.env.local` |
+| `VIBEVOICE_SERVER_URL` | `http://localhost:8000` | `.env.local` |
+
+---
+
+## Python environment rules
+
+- Python deps are managed by [uv](https://docs.astral.sh/uv/) — **never use pip directly**
+- Always `cd server` before running uv commands
+- Add a package: `uv add <package>`
+- Remove a package: `uv remove <package>`
+- Upgrade deps: `uv lock --upgrade`
+- The `[tool.uv.sources]` block in `pyproject.toml` points torch at the CUDA 12.4 index — `--no-sources` bypasses this for CPU installs
+
+---
+
+## Key files
+
+```
+server/
+├── vibevoice_server.py   FastAPI app — /health and /generate (SSE) endpoints
+├── download_model.py     Standalone model prefetch script
+├── start.sh             Startup: parses --cpu flag, syncs venv, launches uvicorn
+└── pyproject.toml       Python deps (torch CUDA index configured here)
+
+web/
+├── app/api/generate/    Proxies POST → Python server, streams SSE to browser
+├── app/api/health/      Proxies GET /health from Python server
+└── app/page.tsx         Main UI
+
+package.json             Root — defines all pnpm dev:* scripts
+dev.sh                   Concurrent launcher (forwards flags to start.sh)
+```
+
+---
+
+## API reference
+
+### `GET /health`
+Returns server status. Safe to poll.
+```json
+{
+  "status": "online",
+  "model": "microsoft/VibeVoice-Realtime-0.5B",
+  "device": "cpu",
+  "voices": ["carter", "davis", "emma", "frank", "grace", "mike"]
+}
+```
+`status` values: `downloading` | `loading` | `online` | `error`
+
+### `POST /generate`
+Streams audio as SSE events.
+```json
+{ "text": "Hello world", "speaker": "carter", "cfg_scale": 1.5, "inference_steps": 10 }
+```
+Event types: `audio_chunk` (base64 float32 PCM) | `complete` | `error` | `cancelled`
+
+---
+
+## Do / Don't
+
+**Do:**
+- Use `pnpm dev:cpu` in Jules — never plain `pnpm dev`
+- Run `git checkout server/uv.lock` if uv rewrites it during setup
+- Keep `_resolve_device()` in `vibevoice_server.py` — it's the CPU/CUDA switching logic
+- Test server changes against `GET /health` and `POST /generate`
+
+**Don't:**
+- Run `uv sync` without `UV_PROJECT_ENVIRONMENT=.venv-cpu` in the Jules sandbox
+- Install Python packages with pip
+- Modify `server/uv.lock` manually
+- Remove the `[tool.uv.sources]` torch entry from `pyproject.toml` — it's needed for CUDA installs

README.md

@@ -25,8 +25,8 @@ The Next.js app proxies audio generation requests to the FastAPI server, keeping
 
 ```bash
 # 1. Clone
-git clone https://github.com/LyAhn/VibePod.git
+git clone https://github.com/JezzWTF/vibepod.git
-cd VibePod
+cd vibepod
 
 # 2. Install Node dependencies (root + web workspace)
 pnpm install
@@ -35,22 +35,39 @@ pnpm install
 cp .env.example .env.local
 
 # 4. Start everything
-pnpm dev
+pnpm dev          # CUDA (requires NVIDIA GPU + driver >= 525.60)
+pnpm dev:cpu      # CPU-only (no GPU required)
 ```
 
-`pnpm dev` starts both services concurrently:
+`pnpm dev` / `pnpm dev:cpu` start both services concurrently:
 
-- **SERVER** — `http://localhost:8000` — on first run `uv sync` creates the Python venv and downloads the ~1 GB VibeVoice model from HuggingFace
+- **SERVER** — `http://localhost:8000` — on first run uv creates the Python venv and downloads the ~1 GB VibeVoice model from HuggingFace
 - **WEB** — `http://localhost:3000` — Next.js dev server with Turbopack
 
 The frontend shows a loading indicator while the model downloads. Once the server reports `status: online`, generation is available.
 
+## CUDA vs CPU
+
+VibePod maintains two completely separate Python virtual environments so CUDA and CPU torch installs never conflict:
+
+| Mode | Command | venv | torch source |
+|------|---------|------|--------------|
+| CUDA (default) | `pnpm dev` | `server/.venv` | PyTorch CUDA 12.4 index |
+| CPU-only | `pnpm dev:cpu` | `server/.venv-cpu` | PyPI (CPU wheel) |
+
+On first run, each mode creates its own venv automatically. You can switch between them freely — they are fully independent. The active device is reported by the `/health` endpoint as `"device": "cpu"` or `"device": "cuda"`.
+
+> **CUDA requirement:** driver >= 525.60 (RTX 30/40 series all qualify). Run `nvidia-smi` to check.
+
 ## Individual commands
 
 ```bash
-pnpm dev:web      # Next.js only
+pnpm dev              # CUDA — server + web
-pnpm dev:server   # Python server only
+pnpm dev:cpu          # CPU  — server + web
-pnpm build        # Production build of the frontend
+pnpm dev:server       # CUDA — Python server only
+pnpm dev:server:cpu   # CPU  — Python server only
+pnpm dev:web          # Next.js only (no Python server)
+pnpm build            # Production build of the frontend
 ```
 
 ## Environment variables
@@ -93,8 +110,8 @@ server/
 | Parameter | Range | Default | Effect |
 |-----------|-------|---------|--------|
 | `speaker` | `carter`, `davis`, `emma`, `frank`, `grace`, `mike` | `carter` | Voice preset used for the generated audio |
-| `cfg_scale` | 0.5 - 4.0 | 1.5 | Higher = more expressive guidance |
+| `cfg_scale` | 0.5 – 4.0 | 1.5 | Higher = more expressive guidance |
-| `inference_steps` | 5 - 20 | 10 | More steps = higher quality, slower generation |
+| `inference_steps` | 5 – 20 | 10 | More steps = higher quality, slower generation |
 
 ## How it works
 
@@ -115,3 +132,5 @@ cd server && uv add <package>
 # Upgrade all dependencies
 cd server && uv lock --upgrade
 ```
+
+> **Note:** The `[tool.uv.sources]` block in `pyproject.toml` pulls torch from the PyTorch CUDA 12.4 index by default. Running with `--cpu` (or `uv sync --no-sources`) bypasses this and installs the standard PyPI CPU wheel instead.