A LINE Official Account that gets hooked up to a chatbot often keeps replying with its old greeting or auto-reply message at the same time as the new bot, so the customer sees two different answers to one message. That happens because LINE ships Greeting Messages and Auto-reply messages switched on by default from the moment the channel is created, and connecting a webhook does not turn them off — someone has to do that by hand in LINE Official Account Manager.
Why customers get two replies after you connect a bot
Most shops set up a Greeting Message or Auto-reply message when they first opened their LINE OA, well before they had any bot — a welcome note, a business-hours message, or a holiday notice. When the shop later connects the Messaging API to a chatbot or a tool like 1CS, both systems now fire on the same trigger: a new friend add, or a customer’s first message in 24 hours. Nothing about adding the webhook disables the old settings, so the customer ends up with a reply from the bot and a leftover reply from LINE’s own auto-responder, often with contradicting information.
What LINE’s own documentation says
LINE’s Building a bot guide states plainly: “The default setting for Greeting Message and Auto-reply messages is Enabled when the channel is created.” It then recommends disabling both in LINE Official Account Manager, specifically to avoid confusion over which system actually sent a reply — advice LINE gives “especially if this is the first time for you to create a LINE Bot.”
A second LINE document, the Development guidelines for partners, lays out which combinations of three settings — Webhooks, Response mode, and Greeting message — are actually allowed. Turning Webhooks off while Response mode and Greeting message are also off is explicitly marked as not allowed, because that combination would leave the LINE Official Account unable to send any message to a customer at all. The order you flip these settings in matters; it isn’t something to toggle all at once without thinking it through.
Turn off LINE’s own defaults first
Before you switch on the webhook for real traffic, open LINE Official Account Manager for the channel you’re connecting and disable Auto-reply messages and Greeting messages — they’re enabled by default, per LINE’s own documentation above. Doing this before the webhook goes live, rather than after, is the order 1CS recommends to avoid the double-reply window; it’s a recommended sequence, not a rule LINE enforces for you.
Set up in 1CS
Connecting LINE to 1CS itself is a separate, standard step. Log in to 1CS, go to Settings > Inboxes, click Add Inbox, and choose the Line channel. Copy the Channel ID and Channel Secret from Settings > Messaging API in LINE Official Account Manager and paste them into the new Line channel form in 1CS, then create the channel. 1CS will show a Callback URL — paste that into the Webhook URL field on the same LINE Official Account Manager page and turn on Use webhook. This is the same flow documented in 1CS’s Connect a LINE inbox guide (Thai only), and LINE is one of eight channels covered by 1CS’s omnichannel inbox.
A pre-launch checklist to copy
Run through this every time a LINE OA gets connected to a bot, or moved to a new one:
[ ] Open manager.line.biz and disable Auto-reply messages
[ ] Disable Greeting messages (or accept it will fire alongside the bot)
[ ] Create the LINE inbox in 1CS and copy its Callback URL
[ ] Paste it into Webhook URL in LINE OA Manager, then turn on Use webhook
[ ] Send a test message from a personal LINE account that has never added this channel
[ ] Count the replies received — only one, from [bot/team name], should arriveFollow that order and the first real customer who messages the account gets a single answer, not two that contradict each other — a detail most generic “connect your LINE webhook” tutorials skip, since they stop at the API call and never mention what LINE already turned on for you.
Two related LINE OA limits worth checking next are LINE OA’s free message quota and how many product cards LINE lets you send in one message.
