name: line-client description: LINE messaging integration via Chrome extension gateway. Send/read LINE messages, manage contacts, groups, profile, and reactions. Authenticate with QR code login. Provides HMAC-signed API access through the Chrome extension gateway (line-chrome-gw.line-apps.com).

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)
• 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

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.

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 cert verified in step 4)
6. checkPinCodeVerified — poll until user enters PIN
7. qrCodeLoginV2 → JWT token + certificate + refresh token

Server-Side Login Script

python scripts/qr_login_server.py /tmp/qr.png

Emits JSON events on stdout: {"event": "qr", "path": "...", "url": "..."}, {"event": "pin", "pin": "123456"}, {"event": "done", "mid": "U..."}.

All API Methods

Contacts & Friends

| Method | Args | Description | |--------|------|-------------| | get_profile() | — | Get your own profile (displayName, mid, statusMessage, etc.) | | get_contact(mid) | mid: str | Get a single contact's profile | | get_contacts(mids) | mids: list[str] | Get multiple contacts | | get_all_contact_ids() | — | List all friend MIDs | | find_contact_by_userid(userid) | userid: str | Search by LINE ID | | find_and_add_contact_by_mid(mid) | mid: str | Add friend by MID | | find_contacts_by_phone(phones) | phones: list[str] | Search by phone numbers | | add_friend_by_mid(mid) | mid: str | Add friend (RelationService) | | get_blocked_contact_ids() | — | List blocked MIDs | | get_blocked_recommendation_ids() | — | List blocked recommendations | | block_contact(mid) | mid: str | Block a contact | | unblock_contact(mid) | mid: str | Unblock a contact | | block_recommendation(mid) | mid: str | Block a friend suggestion | | update_contact_setting(mid, flag, value) | mid, flag: int, value: str | Update contact setting (e.g. mute) | | get_favorite_mids() | — | List favorited contact MIDs | | get_recommendation_ids() | — | List friend suggestions |

Messages

| Method | Args | Description | |--------|------|-------------| | send_message(to, text, ...) | to: str, text: str, reply_to: str (opt) | Send a text message. Supports replies via reply_to=message_id | | unsend_message(message_id) | message_id: str | Unsend/delete a sent message | | get_recent_messages(chat_id, count=50) | chat_id: str | Get latest messages in a chat | | get_previous_messages(chat_id, end_seq, count=50) | chat_id, end_seq: int | Paginated history (older messages) | | get_messages_by_ids(message_ids) | message_ids: list[str] | Fetch specific messages | | get_message_boxes(count=50) | — | Get chat list with last message (inbox view) | | get_message_boxes_by_ids(chat_ids) | chat_ids: list[str] | Get specific chats with last message | | get_message_read_range(chat_ids) | chat_ids: list[str] | Get read receipt info | | send_chat_checked(chat_id, last_message_id) | chat_id, last_message_id: str | Mark messages as read | | send_chat_removed(chat_id, last_message_id) | chat_id, last_message_id: str | Remove chat from inbox | | send_postback(to, postback_data) | to, postback_data: str | Send postback (bot interactions) |

Chats & Groups

| Method | Args | Description | |--------|------|-------------| | get_chats(chat_ids, with_members=True, with_invitees=True) | chat_ids: list[str] | Get chat/group details | | get_all_chat_mids() | — | List all chat MIDs (groups + invites) | | create_chat(name, target_mids) | name: str, target_mids: list[str] | Create a new group chat | | accept_chat_invitation(chat_id) | chat_id: str | Accept group invite | | reject_chat_invitation(chat_id) | chat_id: str | Reject group invite | | invite_into_chat(chat_id, mids) | chat_id: str, mids: list[str] | Invite users to group | | cancel_chat_invitation(chat_id, mids) | chat_id: str, mids: list[str] | Cancel pending invites | | delete_other_from_chat(chat_id, mids) | chat_id: str, mids: list[str] | Kick members from group | | leave_chat(chat_id) | chat_id: str | Leave a group chat | | update_chat(chat_id, updates) | chat_id: str, updates: dict | Update group name/settings | | set_chat_hidden_status(chat_id, hidden) | chat_id: str, hidden: bool | Archive/unarchive a chat | | get_rooms(room_ids) | room_ids: list[str] | Get legacy room info | | invite_into_room(room_id, mids) | room_id: str, mids: list[str] | Invite to legacy room | | leave_room(room_id) | room_id: str | Leave legacy room |

Reactions

| Method | Args | Description | |--------|------|-------------| | react(message_id, reaction_type) | message_id: str, type: int | React to a message. Types: 2=like, 3=love, 4=laugh, 5=surprised, 6=sad, 7=angry | | cancel_reaction(message_id) | message_id: str | Remove your reaction |

Profile & Settings

| Method | Args | Description | |--------|------|-------------| | update_profile_attributes(attr, value, meta={}) | attr: int, value: str | Update profile. Attrs: 2=DISPLAY_NAME, 16=STATUS_MESSAGE, 4=PICTURE_STATUS | | update_status_message(message) | message: str | Shortcut: update status message | | update_display_name(name) | name: str | Shortcut: update display name | | get_settings() | — | Get all account settings | | get_settings_attributes(attr_bitset) | attr_bitset: int | Get specific settings | | update_settings_attributes(attr_bitset, settings) | attr_bitset: int, settings: dict | Update settings |

Polling & Events

| Method | Args | Description | |--------|------|-------------| | get_last_op_revision() | — | Get latest operation revision number | | fetch_ops(count=50) | — | Fetch pending operations (may long-poll) | | poll() | — | Generator yielding operations as they arrive | | on_message(handler) | handler: Callable(msg, client) | Start polling thread, calls handler on new messages. Op types: 26=SEND_MESSAGE, 27=RECEIVE_MESSAGE | | stop() | — | Stop the polling thread |

Other Services

| Method | Args | Description | |--------|------|-------------| | get_server_time() | — | Get LINE server timestamp | | get_configurations() | — | Get server configurations | | get_rsa_key_info() | — | Get RSA key for auth | | issue_channel_token(channel_id) | channel_id: str | Issue channel token (LINE Login/LIFF) | | get_buddy_detail(mid) | mid: str | Get official account info | | report_abuse(mid, category=0, reason="") | mid: str | Report a user | | add_friend_by_mid(mid) | mid: str | Add friend (RelationService) | | logout() | — | Logout and invalidate token |

MID Format

LINE identifies entities by MID:

• U... or u... → User (toType=0)
• C... or c... → Group chat (toType=2)
• R... or r... → Room (toType=1)

The client auto-detects toType from the MID prefix when sending messages.

HMAC Signing

All API calls require X-Hmac header. The WASM signer handles this automatically:

• Derives key from version "3.7.1" + access token via proprietary KDF (in lstm.wasm)
• Signs path + body → base64 → X-Hmac
• Server mode: ~13ms/sign (Node.js HTTP server on port 18944, auto-started)
• Subprocess mode: ~2s/sign (fallback)

Error Handling

from src.chrome_client import APIError

try:
    client.send_message(mid, "test")
except APIError as e:
    print(e.code, e.api_message)
    # 10051 = session expired / invalid
    # 10052 = HTTP error from backend
    # 10102 = invalid arguments

Architecture

User's Phone (LINE app)
    ↕ (scan QR / enter PIN)
LINE Servers (line-chrome-gw.line-apps.com)
    ↕ (JSON REST + X-Hmac signing)
LineChromeClient (this repo)
    ↕ (WASM HMAC via Node.js signer)
lstm.wasm + lstmSandbox.js

The Chrome Gateway translates JSON ↔ Thrift internally. We never deal with Thrift binary — everything is clean JSON.