Chat App with File Sharing – Google Sheets Apps Script

The second release of the Google Sheets chat app. Everything from the first build is still here — signup, blue seen ticks, presence, email alerts — and on top of it sits the set of things people asked for after using it: attachments, deleting messages, blocking people yourself, and a refresh loop fast enough that a conversation feels live.

Files in the conversation

Images and PDFs can be sent directly in a chat, with an optional caption typed before sending, and the recipient opens them inside the app rather than downloading a mystery link. An upload notice runs while the file is on its way.

Taking messages back

Any message you sent can be deleted on its own, or all of them at once, and the other side sees a clear message-deleted marker rather than a silent gap. Messages the other person sent stay under their control — you cannot delete someone else's words out of your own thread.

Blocking without an admin

Users block and unblock each other themselves, with a blocked list to manage it, and a blocked sender is told plainly that they are not allowed to message that person. Sound effects fire on send and receive, a browser notification lands when a message arrives, and messages appear within about a second.

Changing your name safely

A username change is checked for duplicates and then applied backwards through your chat history, so the person you were talking to last week still sees the same identity rather than a stranger's name on old messages.