Hey there! Let’s break down your questions one by one based on hands-on experience with Line’s developer tools:

Short answer: No, not for messages sent by other users. The Line Messaging API only lets your bot delete messages that it itself has sent. There’s no endpoint to remove messages posted by other group members directly through the API.

If you need to handle unwanted messages from other users, your best bet is to either:

• Use Line’s native group admin features (manually deleting messages or setting permissions)
• Build a workaround where your bot detects the message and prompts human group admins to take action via a private alert.

Absolutely—this is a common use case, though you’ll need to work around the message deletion limitation I mentioned earlier. Here’s how most developers approach it:

• Set up webhook listening: Configure your bot to receive all incoming message events from the group. This lets you check the sender’s user ID every time someone posts.
• Whitelist approved users: Maintain a list of user IDs that are allowed to send messages in the group. When a message comes in, cross-reference the sender’s ID against this list.
• Handle non-approved senders:
  • Since you can’t delete their message via the API, you can post a clear message in the group (e.g., *This message violates group rules—only approved users may post here*) to signal that the content isn’t permitted.
  • Immediately send a private message to the non-approved user via the Messaging API, explaining the group’s rules and why their message wasn’t allowed.
• Boost effectiveness with admin privileges: Make your bot a group admin. This lets you use Line’s native tools to mute non-compliant users temporarily, which adds an extra layer of enforcement alongside your bot’s messaging.

I’ve seen several developers build similar bots for Line groups—they’re effective for keeping conversations controlled, even without direct message deletion capabilities.

内容的提问来源于stack exchange，提问作者JSowa