line

library0.8.2pypypi✓ verified 31d ago

LINE Messaging API enables bot development for LINE, the dominant messaging platform in Japan, Thailand, and Taiwan with 196M+ monthly users. Official SDKs exist for Python and Node.js. Primary documentation is in Japanese — English docs are complete but may lag Japanese versions.

communication

pip install line-bot-sdk

package ↗homepage ↗

INSTALL

IMPORT

SIG · LINE

line

communicationpythonv0.8.2

Install

8.1s avg

Import

1503ms

Disk

157MB

Pass rate

10/ 10

Env Coverage10 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v? · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

py 3.10–3.95 runs

installs and imports cleanly · install 0.0s · import 1.578s · 117.5MB

glibc

py 3.10–3.95 runs

installs and imports cleanly · install 8.1s · import 1.428s · 189MB

157MB installed

● package 157MB

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

WebhookHandler (Python v3)

✓ from linebot.v3 import WebhookHandler

✗ from linebot import WebhookHandler

linebot v2 imports (no .v3) still work but are legacy. All new code should use linebot.v3 namespace.

MessagingApi (Python v3)

✓ from linebot.v3.messaging import Configuration, ApiClient, MessagingApi

✗ from linebot import LineBotApi

LineBotApi is the v2 class. Replaced by MessagingApi in v3. Both still work but v3 is current.

Minimal LINE bot webhook handler using linebot.v3 SDK with Flask.

from flask import Flask, request, abort from linebot.v3 import WebhookHandler from linebot.v3.exceptions import InvalidSignatureError from linebot.v3.messaging import ( Configuration, ApiClient, MessagingApi, ReplyMessageRequest, TextMessage ) from linebot.v3.webhooks import MessageEvent, TextMessageContent app = Flask(__name__) configuration = Configuration(access_token='YOUR_CHANNEL_ACCESS_TOKEN') handler = WebhookHandler('YOUR_CHANNEL_SECRET') @app.route('/callback', methods=['POST']) def callback(): signature = request.headers['X-Line-Signature'] body = request.get_data(as_text=True) try: handler.handle(body, signature) except InvalidSignatureError: abort(400) return 'OK' @handler.add(MessageEvent, message=TextMessageContent) def handle_message(event): with ApiClient(configuration) as api_client: line_bot_api = MessagingApi(api_client) line_bot_api.reply_message( ReplyMessageRequest( reply_token=event.reply_token, messages=[TextMessage(text=event.message.text)] ) ) if __name__ == '__main__': app.run()

Debug

Known issues

breakingSignature verification is mandatory. Never process webhook events without verifying X-Line-Signature header using HMAC-SHA256 with your channel secret.

fix

Always call handler.handle(body, signature) and catch InvalidSignatureError. Abort 400 on failure.

affects: all

breakingDo not use body parsers (bodyParser.json, express.json) before LINE webhook middleware in Node.js. Pre-parsing the body breaks signature verification.

fix

Register LINE middleware before any body parser middleware on the webhook route

affects: all

breakingReply tokens are single-use and expire in 30 seconds. Storing and reusing a reply token will fail silently.

fix

Use push messages (push_message API) for delayed or async responses instead of reply tokens

affects: all

gotchaWebhook endpoint must return HTTP 200 within 30 seconds. LINE Platform retries failed webhooks if webhook redelivery is enabled.

fix

Process webhook events asynchronously. Return 200 immediately, handle events in background.

affects: all

gotchaChannel access token and channel secret are different credentials. Confusing them is the most common setup error.

fix

Channel secret → WebhookHandler constructor. Channel access token → Configuration/MessagingApi.

affects: all

gotchaNo error is returned when pushing messages to users who have blocked the bot. Delivery silently fails.

fix

Track opt-out webhook events to maintain your own block list and avoid unnecessary push API calls.

affects: all

gotchaContent from user messages (images, video, audio) must be fetched separately via GET /v2/bot/message/{messageId}/content using api-data.line.me domain, not api.line.me.

fix

Use https://api-data.line.me/v2/bot/message/{messageId}/content for binary content retrieval

affects: all

breakingMissing required Python packages (e.g., Flask, Django, etc.) will cause a `ModuleNotFoundError` when the application attempts to import them. This prevents the application from starting or functioning correctly.

fix

Ensure all necessary Python packages are installed in the environment where the script is executed. This can be done using `pip install <package_name>` for individual packages or `pip install -r requirements.txt` if a `requirements.txt` file is used to list dependencies.

affects: all

Errors

Common errors & fixes

InvalidSignatureError: <InvalidSignatureError [Invalid signature. signature=...]>

The webhook signature sent by the LINE Platform does not match the signature calculated by your bot server, often due to an incorrect Channel Secret or modifications to the request body before verification.

fix

Ensure the 'Channel Secret' in your bot application exactly matches the one in the LINE Developers Console, and use the raw request body without any modification (e.g., pretty-printing JSON) for signature validation with UTF-8 encoding.

LineBotApiError [Authentication failed due to the following reason: invalid token. Confirm that the access token in the authorization...]

The Channel Access Token used for API requests is invalid, expired, revoked, or incorrectly configured.

fix

Verify that the 'Channel Access Token' in your code is correct and currently valid in the LINE Developers Console. If it's a short-lived token, ensure it hasn't expired, and if it's been reissued or revoked, obtain a new valid token.

Request failed with status code 400

This error, often accompanied by an 'invalid replyToken', indicates an issue with the request payload sent to the LINE Messaging API, such as using an expired, already used, or incorrectly formatted reply token or message object.

fix

Ensure the 'reply_token' is used immediately after receiving the event and has not been used before, as reply tokens are single-use and time-sensitive. Also, verify that the message objects in your request adhere to the LINE Messaging API specifications.

ModuleNotFoundError: No module named 'linebot'

The 'line-bot-sdk' Python package has not been installed or is not accessible in the current Python environment.

fix

Install the library using pip: `pip install line-bot-sdk`. Confirm that your script is being executed within the Python environment where the package was installed.

LineBotSdkDeprecatedIn30: Call to deprecated method ... (Use 'from linebot.v3.messaging import MessagingApi' and 'MessagingApi(...)....' instead. See https://github.com/line/line-bot-sdk-python/blob/master/README.rst for more details.) -- Deprecated since version 3.0.0.

Your code is using older modules or methods from the `linebot` (version 2.x) namespace, but a newer version of the SDK (3.x) is installed, which has introduced a `v3` namespace with breaking changes.

fix

Update your imports and code to use the `linebot.v3` modules and classes as specified in the deprecation warning, adapting your code to the new API structure.

Upgrade

Version history

0.8.2latest on PyPI · released Nov 21, 2016

Audit

Dependencies

flaskoptionalRequired for webhook server in Python examples. Any WSGI framework works.

Agent activity

27 hits · last 30 days

node

OpenAI (training)

Resources

packagehttps://pypi.org/project/line/ ↗

homepagehttp://carpedm20.github.io/line ↗