line-go

An experimental Go client for the LINE Android 26.11 protocol, designed for persistent SYNC4 listeners, E2EE v2 messaging, multi-account workloads, and editable bot examples.

This is an unofficial project. Use it only with accounts and groups you are authorized to manage. Avoid excessive requests and respect LINE rate limits.

Features

• QR/PIN login with an atomically saved local session
• Phone registration with LINE's official manual human-verification flow
• Access-token renewal through refresh tokens
• getProfile, chat listing, message history, and message-box operations
• Persistent SYNC4 listener with revision recovery and worker pools
• E2EE v2 text decryption and sending for direct and group chats
• Self bot, public bot, and multi-account guard examples
• Configurable endpoints, hosts, application identity, and session paths

Requirements

• Go 1.23 or newer
• A LINE account you are authorized to use
• Chrome or Chromium when phone registration requires human verification

Build

go build -o bin/linego ./cmd/linego
go build -o bin/guard_bot ./examples/guard_bot

Generated binaries, sessions, credentials, tokens, local account files, logs, and QR images are excluded by .gitignore.

QR login

go run ./cmd/linego qr

The command prints a scannable QR code, writes linego-login-qr.png, waits for PIN confirmation when required, and saves the session to .linego/session.json with 0600 permissions. Tokens are never printed.

Phone registration

The password is read from the environment instead of a command-line argument:

export LINEGO_REGISTER_PASSWORD='StrongPass9!'
go run ./cmd/linego register \
  --phone 0812345678 \
  --region TH \
  --display-name "LINE User"

You can also start registration without command-line options:

export LINEGO_REGISTER_PASSWORD='StrongPass9!'
go run ./cmd/linego register

When no registration options are supplied, the CLI asks only for the required two-letter country/region code and phone number. It requests the SMS PIN after LINE sends it. Use TW for Taiwan, TH for Thailand, JP for Japan, KR for Korea, or HK for Hong Kong. The display name remains LINE User; the device model and application identity use the built-in Android defaults.

The CLI validates that the mobile-number format matches the selected region before contacting LINE. It accepts common local and international formats and prints the expected format when they do not match.

The account password is intentionally not prompted or accepted as a command-line option. Set LINEGO_REGISTER_PASSWORD before starting so it does not appear in shell history or the process list.

The password must contain at least 8 characters and at least 3 of these 4 categories: an uppercase letter, a lowercase letter, a number, and a symbol.

If LINE returns error 5, the client opens an isolated browser profile for the official https://w.line.me human-verification flow. Complete the challenge manually. CAPTCHA solving and verification bypasses are not implemented. When HTTPS_PROXY is configured, Chrome uses the same proxy as the LEGY registration session. Authenticated proxy credentials remain in the Go process behind a temporary loopback bridge and are not included in Chrome's command line.

Successful registration stores the access token, refresh token, and session metadata in .linego/session.json. Registration can be customized with project-specific environment variables:

• LINEGO_REGISTER_APP — Android application identity
• LINEGO_REGISTER_DEVICE — device model reported to LINE
• LINEGO_REGISTER_NAME — default profile display name
• LINEGO_REGISTER_PHONE — default phone number
• LINEGO_REGISTER_REGION — default two-letter region code
• LINEGO_VERIFICATION_BROWSER — Chrome/Chromium executable path
• LINEGO_SIM_HNI — SIM HNI/MCC-MNC reported during registration
• LINEGO_SIM_CARRIER — SIM carrier name reported during registration

The same values can be supplied explicitly with --registration-application, --device-model, --display-name, and --browser. Use --human-verification-timeout 5m to change the manual challenge timeout.

SMS is selected automatically by default. If LINE reports voice verification as available, use --verification-method voice to receive the PIN through an automated call. The CLI prints the normalized destination in masked form and lists the methods returned by LINE. LINEGO_REGISTER_VERIFICATION can be set to auto, sms, or voice.

When SIM metadata is known, provide HNI and carrier together. For example, a Chunghwa Telecom profile in Taiwan can be supplied as follows:

export LINEGO_SIM_HNI='46692'
export LINEGO_SIM_CARRIER='Chunghwa'

The equivalent CLI options are --sim-hni 46692 --sim-carrier Chunghwa. Do not guess these values when the real mobile carrier is unknown.

CLI

go run ./cmd/linego profile
go run ./cmd/linego refresh
go run ./cmd/linego ticket
go run ./cmd/linego sync
go run ./cmd/linego listen --workers 4
go run ./cmd/linego chats
go run ./cmd/linego send <TARGET_CHATID> "hello"
go run ./cmd/linego e2ee-check

refresh exchanges the stored refresh token for a new access token and saves rotated credentials atomically. V3_TOKEN_CLIENT_LOGGED_OUT indicates a closed session and requires a new login rather than a normal refresh.

send automatically retries with E2EE v2 when the destination requires it or LINE returns service error 82.

Extended Talk APIs

The client includes typed wrappers for contacts, chat management, recent messages, announcements, followers, configuration, and E2EE key lookup:

contacts, err := line.GetAllContactIDs(ctx)
blocked, err := line.GetBlockedContactIDs(ctx)

chat, err := line.CreateChat(ctx, "New group", []string{"USER_MID"}, 0, "")
err = line.UpdateChatName(ctx, chat.MID, "Renamed group")
err = line.UpdateChatTicket(ctx, chat.MID, false)

messages, err := line.GetRecentMessages(ctx, chat.MID, 50)
announcements, err := line.GetChatAnnouncements(ctx, chat.MID)
_, err = line.CreateChatAnnouncement(
	ctx, chat.MID, "Important notice", "https://example.com/notice",
)

Low-level request and response values remain available through line.Talk for applications that need fields not represented by the convenience models.

Bot examples

go run ./examples/self_bot
go run ./examples/public_bot

The self bot processes only the account's own op.type 25 messages. The public bot processes op.type 25 and 26. Their command maps are intentionally kept inside the examples so users can edit behavior directly.

Multi-account listener

The same accounts.json format is used by both the multi-account listener and the guard bot. Start from the shared example:

cp accounts.example.json accounts.json
go run ./cmd/linego multi-listen --accounts accounts.json

.linego/session.example.json documents the session-file structure. Prefer creating real session files through login instead of editing tokens manually:

LINEGO_SESSION_PATH=.linego/session.json go run ./cmd/linego qr
LINEGO_SESSION_PATH=.linego/second.json go run ./cmd/linego qr

These paths match the two entries in accounts.example.json. Add or remove account entries and session files as needed.

Each account receives an isolated session, HTTP/2 transport, revision stream, and handler worker pool. Do not place raw tokens in the account configuration; reference local session files instead.

Guard bot

cp accounts.example.json accounts.json
cp .linego/guard.example.json .linego/guard.json
go run ./examples/guard_bot \
  --accounts accounts.json \
  --state .linego/guard.json

The example guard state contains no account IDs or group IDs. If creator is left empty, the first user who invites a guard account becomes a Creator.

Validate account profiles and application identities without starting listeners:

go run ./examples/guard_bot \
  --accounts accounts.json \
  --state .linego/guard.json \
  --check

The guard supports persistent roles, group-specific administrators, blacklist management, protection settings, health-aware account selection, history, lurk/readers, and time-limited war mode. The first user who invites a guard account becomes a Creator when the state has no Creator.

Role hierarchy:

Creator > Owner > Admin > GAdmin > User

See GUARD_COMMANDS.md and WAR_COMMANDS.md for the complete command reference.

Environment

• LINEGO_API_HOST
• LINEGO_APPLICATION
• LINEGO_LANGUAGE
• LINEGO_API_TIMEOUT
• LINEGO_SESSION_PATH
• LINEGO_TO_TYPE
• LINEGO_DEBUG=true

Debug mode logs short SHA-256 fingerprints instead of credential values.

Project layout

api/           Endpoint and shared Thrift method constants
auth/          QR orchestration and X25519 handling
client/        Profile, chat, message, SYNC4, and listener APIs
config/        Hosts, application identity, defaults, and environment settings
e2ee/          Keychains, AES-CBC/AES-GCM, and key caches
examples/      Editable self, public, and guard bots
guard/         Roles, state, protection, health, and war-mode engine
multi/         Isolated multi-account listener manager
protocol/      Compact and binary Thrift codecs
qrdisplay/     Terminal and PNG QR rendering
registration/  PAIS/LEGY phone registration and manual verification
service/       TalkService, QR, and token-refresh calls
storage/       Atomic session persistence
transport/     Shared HTTP/2 and keep-alive transport
cmd/linego/    Command-line interface

Security

• Never commit .linego/, accounts.json, .env, credential exports, private keys, or generated QR images.
• Rotate any credential that has previously been pasted into a chat, log, issue, commit, or public repository.
• Keep local session and account files at 0600 permissions.
• Review example configuration before use; it must contain placeholders only.

Support and contact

If you encounter a problem, find something that should be added, or want to suggest an improvement, contact the project maintainer: