Important:
This mod has been closed and there will be no active
development. Reason is, u/The_CodedOne has been working on the same mod,
and is ~~almost~~ finished. There would
be no point in competing Mods, so i'm gonna scrap this project ~~and~~
~~you're gonna have to wait until his Mod reaches release status~~. Thanks
for all the excitement - it was a short time (only 2 days lol), but i
enjoyed it.
Also, CDAGaming just released another RPC mod called CraftPresence - one of those should fit your need.

I was kinda surprised noone made a Mod for this yet, but well... here i am.

A quick explanation to those of you who don't know Discord: It's a relatively young Voice- and Textchat Service dedicated to Gamers, that has quickly become one of the top competitors in this sector. Creating an account is free, as is your personal server and everything else.

Just recently, Discord announced Rich Presence: A System that would allow Games to display their Info "live" on the User's profile. This includes the current Gamemode, remaining Time, Score, Party Members - You name it. Games can even add "Join" and "Spectate" Buttons, although these are still in Beta and can only be used by approved Developers.

Introducing - Minecraft-RPC!

Of course i hope that one day, Minecraft will natively support Rich Presence - but why wait? Just install this Mod and you're good to go.

Current Features (v1.1):

Enables fancy Rich Presence instead of the plain "is playing Minecraft" text
Displays wether you are in Singleplayer, Multiplayer or idle in the Main Menu
Shows elapsed time since your status changed last
Configurable client ID - you can use your own Rich Presence Application
Configurable Image Keys and Image Hover-over texts

The feature list is still short, but i only started this Mod today, so bear with me. I only layed the foundation so far. If you want to chat with me about features, feel free to DM me on Discord (@M*C*O#9635) or join my server.

In case you didn't realize it yet:

This Mod will send your current Gamestate to a third party service and display it publicly to anyone able to view your profile (= anyone that has ever DM'd you or is on one of the same servers as you are part of). You have been warned.

Changelog

1.0

Added Basic Functionality: Both images, hover-over texts and basic Details (Main Menu/Singeplayer/Multiplayer)

1.1
- Added Config with variables for both images, both hover-over texts and the Client ID

If you have any legal questions: Read the license - trust me, it's a good read.

[Discontinued] Minecraft-RPC