Linejs

linejs

@evex/linejs is a TypeScript-first client library for the LINE Messenger protocol. It speaks LINE's Thrift binary wire format directly, supports E2EE, polling for events, and ships hand-written wrappers for the methods CHRLINE-Patch covers.

This skill is a roadmap, not a manual. The library moves fast; rather than freezing details that will rot, this file points the agent at the canonical sources to read on demand.

Install

deno add jsr:@evex/linejs
# Types are also available standalone:
deno add jsr:@evex/linejs-types

Latest release: check JSR — https://jsr.io/@evex/linejs or curl -s https://jsr.io/@evex/linejs/meta.json | jq -r .latest. The skill prompt does not pin a version; pin in user code.

Minimum-viable bot

import { BaseClient } from "@evex/linejs/base";
import { FileStorage } from "@evex/linejs/storage";

const storage = new FileStorage("./storage.json");
const client = new BaseClient({ device: "DESKTOPWIN", storage });

client.on("qrcall",  (url) => console.log("scan:", url));
client.on("pincall", (pin) => console.log("PIN:", pin));
client.on("update:authtoken", (t) => storage.set(".auth", t));

const cached = await storage.get(".auth");
await client.loginProcess.login(
    typeof cached === "string" ? { authToken: cached } : {},
);

for await (const op of client.createPolling().listenTalkEvents()) {
    if (op.type === "RECEIVE_MESSAGE" || op.type === "SEND_MESSAGE") {
        const msg = await client.e2ee.decryptE2EEMessage(op.message);
        if (msg.text === "!ping") {
            await client.talk.sendMessage({
                to: msg.to === client.profile?.mid ? msg.from : msg.to,
                text: "pong!",
                e2ee: !!op.message.chunks,
            });
        }
    }
}

That's the smallest useful bot. For richer surfaces start with the Client wrapper in @evex/linejs (it builds on BaseClient) — it has getMyProfile(), updateMy{DisplayName,StatusMessage,Profile}(), fetchJoinedChats(), getChat(), getUser(), uploadMyProfileImage(), uploadMyProfileBackground() and more.

Roadmap — where to look for what

In all cases, looking at the latest code is best. https://github.com/evex-dev/linejs

When in doubt, read the source under packages/linejs/client/features/ — feature classes are short and read like documentation.

Known constraints

• LINE 26+ requires the ForSecure QR login (createQrCodeForSecure + qrCodeLoginV2ForSecure). Legacy createQrCode is silently expired by the server. linejs v2.7+ uses ForSecure by default; older versions cannot log in.
• map<i32, V> encoding was broken on JS-object keys before v2.7 — JS keys are strings, the encoder rejected them. Fixed in v2.7. If you're targeting older linejs, build the map as a NestedArray tuple.
• E2EE decryption is required for most chat messages — see client.e2ee.decryptE2EEMessage(op.message). Don't read op.message.text directly.
• Agent I needs Yahoo cookies. The LINE Android app loads the WebView with whatever Yahoo session the user already has; programmatic use requires you to obtain those cookies yourself (Yahoo Japan login → extract cookies). linejs ships the call shape, not the auth.
• Device type matters for feature gating. DESKTOPWIN lacks several APIs that ANDROID has (e.g. getContactsV3, getContactCalendarEvents). For pure bot work DESKTOPWIN is usually enough; if a method returns API method not capable, switch device type or use a legacy fallback.

Bugs / issues

Report to https://github.com/evex-dev/linejs/issues. Useful context to include:

• linejs version (deno info jsr:@evex/linejs shows resolved version)
• device type and LINE app version you're targeting
• minimal repro: the smallest snippet that reproduces, plus the error from Request internal failed: status=… headers=… body=<…> (v2.7+ includes the HTTP status / headers in the thrown message — very helpful for triage)
• if QR login–related: which step (createSession, createQrCodeForSecure, checkQrCodeVerified, qrCodeLoginV2ForSecure) and the [login] ForSecure: maxCount=… intervalSec=… nonce=… debug line if it printed.

CHRLINE-Patch-compatible behaviour reports (e.g. "this RPC works in CHRLINE but not linejs") are also useful — name the method and we'll port it.

What this skill deliberately does NOT contain

• Frozen API signatures — they change. Read the source.
• A list of every wrapped method — there are 130+, see packages/linejs/base/service/ for the live set.
• Reverse-engineering details for LINE Android — Join Our Discord.