line-client

# LINE Client Skill

Full LINE messaging client via the Chrome extension gateway JSON API.

## Repo & Files

- **Repo:** `/data/workspace/line-client` ([github.com/2manslkh/line-api](https://github.com/2manslkh/line-api))
- **Main client:** `src/chrome_client.py` → `LineChromeClient`
- **QR login:** `src/auth/qr_login.py` → `QRLogin`
- **HMAC signer:** `src/hmac/signer.js` (Node.js, auto-starts on port 18944)
- **Token storage:** `~/.line-client/tokens.json`
- **Certificate cache:** `~/.line-client/sqr_cert`
- **WASM files:** `lstm.wasm` + `lstmSandbox.js` (required, in repo root)

## Quick Start

```python
import json
from pathlib import Path
from src.chrome_client import LineChromeClient

tokens = json.loads((Path.home() / ".line-client" / "tokens.json").read_text())
client = LineChromeClient(auth_token=tokens["auth_token"])

# Send a message
client.send_message("U...", "Hello!")

# Get profile
profile = client.get_profile()
```

Tokens expire in ~7 days. If expired (`APIError(10051)`), re-run QR login.

## QR Login (Authentication)

QR login requires user interaction: scan QR on phone + enter PIN.

```python
from src.hmac import HmacSigner
from src.auth.qr_login import QRLogin
import qrcode

signer = HmacSigner(mode="server")
login = QRLogin(signer)
result = login.run(
    on_qr=lambda url: send_qr_image_to_user(qrcode.make(url)),
    on_pin=lambda pin: send_pin_to_user_IMMEDIATELY(pin),  # TIME SENSITIVE!
    on_status=lambda msg: print(msg),
)
# result.auth_token, result.mid, result.refresh_token
```

**Critical:** The PIN must reach the user within ~60 seconds. Send it the instant `on_pin` fires.

### QR Login State Machine
1. `createSession` → session ID
2. `createQrCode` → callback URL (append `?secret={curve25519_pubkey}&e2eeVersion=1`)
3. `checkQrCodeVerified` — poll until scan (uses `X-Line-Session-ID`, no `origin` header)
4. **`verifyCertificate`** — MUST be called even if it fails (required state transition!)
5. `createPinCode` → 6-digit PIN (skip if ce...