Overview

JAMES (Just A Machine, Engineered for Speech) is a browser-native AI chat interface. It runs a quantized language model entirely inside your browser using WebGPU or WASM — no server, no API, no data leaving your device.

Conversation state is persisted in IndexedDB. Model weights are cached by the browser after first download. Once cached, JAMES works completely offline.

Model Loading

On first launch, JAMES downloads model weights from Hugging Face. This is a one-time operation — weights are cached by the browser indefinitely.

Model files are fetched in parallel chunks and cached locally, so the download can recover gracefully and load faster on future launches.

The progress bar at the top of the terminal reflects download progress. Status transitions are:

downloading → streaming → complete → done

Backends

JAMES selects the best available execution path for your hardware and automatically falls back if a preferred backend is unavailable.

WebGPU — primary (GPU)

The preferred high-performance backend for Chrome/Edge with a compatible GPU. JAMES tries progressively larger models based on your available VRAM.

GPU models (WebGPU / q4f16):
  Qwen2.5 0.5B   — ~400 MB  (auto-select)
  SmolLM2 1.7B   — ~950 MB  (auto-select)
  Llama 3.2 1B   — ~750 MB  (auto-select)
  Qwen2.5 1.5B   — ~950 MB  (auto-select)
  Llama 3.2 3B   — ~2.1 GB  (auto-select)
  Gemma 3 1B     — ~600 MB  (manual only)
  DeepSeek-R1 1.5B — ~1 GB  (manual only)
  Phi-3.5-mini 3.8B — ~2.2 GB (manual only)

WASM — CPU fallback

Used when WebGPU is unavailable. Slower but compatible with any modern browser.

CPU models (WASM / q4 or q8):
  Llama 3.2 1B   — ~650 MB
  TinyLlama 1.1B — ~600 MB
  Qwen2.5 0.5B   — ~400 MB
  SmolLM2 1.7B   — ~950 MB

Threads

Each conversation is a thread in the sidebar. Threads represent independent context histories and are saved locally.

• Click + New Chat to start a fresh session.
• Thread titles are derived from the first user message.
• Use the × button to delete a thread permanently.
• The active thread and its history are stored in IndexedDB and restored on revisit.

Stop Generation

The stop button terminates the worker and restarts generation state.

1. Worker is terminated immediately.
2. Partial streamed text is saved if available.
3. The model restarts from the browser cache.

Python Execution

JAMES can execute Python code in-browser via Pyodide. Ask JAMES to run a Python calculation and it will use the python tool automatically:

```tool:run
{"tool": "eval_python", "params": {"code": "import math; print(math.factorial(20))"}}
```

Execution results are returned into the conversation and used to answer your query. Pyodide loads on first use; subsequent calls are instant.

Tool Reference

JAMES uses model-driven tool calling. When you ask a question that needs live or external data, the model emits a tool call block, the app executes it, and feeds the result back to the model for a final answer:

```tool:run
{"tool": "weather", "params": {"location": "Tel Aviv"}}
```

Both JSON and XML formats are supported in addition to the legacy key: value format. The app auto-detects which format was used.

Information Tools

{"tool": "weather", "params": {"location": "Tel Aviv"}}

{"tool": "wikipedia", "params": {"query": "Bijective numeration"}}

{"tool": "currency", "params": {"from": "USD", "to": "EUR", "amount": 100}}

time
timezone: Asia/Jerusalem

date
action: diff, date: 2025-01-01, date2: 2026-01-01

web_search
query: best local AI models 2025

fetch_page
url: https://news.ycombinator.com

ip
target: self

Utility Tools

uuid
count: 3

password
length: 24, count: 1, symbols: true

timer
seconds: 1500, label: Pomodoro

calculator
expr: (12 * 8) / 3 + sqrt(144)

convert
value: 100, from: km, to: miles

base64
mode: encode, value: Hello World

hash
algorithm: sha256, value: hello

color
mode: hex2rgb, hex: #ff6b6b

random
mode: dice, count: 2, sides: 6

countdown
target: 2027-01-01

ascii_art
text: JAMES

python
code: print('Hello from Python')

palette
base: #00ff41, scheme: triadic, count: 5

file
filename: data.txt, content: ...

search
query: browser inference

write_note
note: User's name is Alex and they are 28 years old.

Device Tools

clipboard

location

Games ♟️

JAMES has two fully playable games built into the chat. Just say "let's play chess" or "start a game of checkers" — a live board appears right in the conversation.

start_game
game: chess

start_game
game: checkers

make_move
move: e5          <!-- Chess SAN -->

make_move
move: 5,2 to 4,3  <!-- Checkers row,col -->

Architecture

The application is modularized for efficiency: the worker layer (split into multiple specialized worker-*.js modules) owns inference and model state. The main thread owns the UI, the modular tool routing system, and storage.

Privacy Model

JAMES is designed so no conversation data leaves your browser unless you explicitly request external information via tools.

Service Worker

The service worker caches static app assets as an enhancement. Model weights bypass the SW and use the browser cache instead.

• App logic: network-first.
• CDN assets: cache-first.
• Model weights: browser cache.