- Seppuku is free, open source, and built for MC 1.12.2 anarchy servers, a version most of the game moved past years ago.
- Opal is $8.99 and actively developed for MC 26.2, with 70 modules tuned for BedWars/SkyWars-style minigame combat.
- Setup is launcher, login, play on Opal. Seppuku means installing Forge yourself and dropping the mod in.
- These two are not really fighting for the same player: one is an anarchy client frozen in place, the other is a minigame client still shipping updates.
- If you are on MC 1.12.2, want free and open source, and do not mind that development stopped years ago, Seppuku is a legitimately solid pick.
At a glance
| Feature | Opal | Seppuku |
|---|---|---|
| Price | $8.99, one-time | Free (open source) |
| Source | Closed source | Open source |
| Tuned for | BedWars / SkyWars-style minigame combat | Anarchy servers |
| Setup | Launcher, login, play | Install Forge, drop the mod in, launch |
| Updates and support | Active development on the current release | Legacy, no longer maintained |
| Minecraft version | MC 26.2 | MC 1.12.2 |
Opal by the numbers
Free and open source, or $8.99 and closed
If cost is the deciding factor, Seppuku wins outright. It is open source: the code is there to read, build, or fork, and nobody is asking you to pay for it. That is a real, honest advantage, and we are not going to argue around it.
Opal costs $8.99, one-time, no subscription. It is closed source. What that money buys is a client somebody is still actively building: a launcher that logs you in and drops you into a match, a real interface instead of a bare clickgui, and a module set kept current for the Minecraft version people are actually playing on right now.
Two different servers, two different clients
This is the honest part: Seppuku is built for anarchy servers, where the point is chaos and griefing with effectively no rules. Opal is built around BedWars/SkyWars-style minigame combat, tuned for winning organized fights on most servers rather than surviving lawlessness on one. If you are choosing between these two for the same reason, you are probably choosing wrong. They solve different problems for different players.
Credit where it is due: keeping an anarchy client open source and free for as long as Seppuku has is a genuinely useful thing for that corner of the game, even years after development stopped.
A legacy client vs one still being pushed forward
Seppuku is marked legacy and built for MC 1.12.2, a version most servers moved past years ago. It still works for players who never left that version, but nothing new is coming; the project stopped in place.
Opal tracks MC 26.2, the current release, on Java 25 via Fabric. It is marked active, meaning it keeps getting attention as Minecraft updates, rather than sitting frozen wherever development happened to stop.
What is documented about each
To be straight about it, public documentation on Seppuku is thin. What is known: it is open source, a Forge mod for MC 1.12.2, built for anarchy play, and several of its modules were later reused by SalHack, which says something about how much other client developers valued its code even after Seppuku itself went quiet.
Opal's architecture is fully documented: 70 modules split across combat, movement, visual, world, and utility, a custom glass UI engine, and an embedded GraalJS scripting engine that most clients at this price point do not attempt. That is not a knock on Seppuku, just a difference in how much either client has published about itself.
When Seppuku is the better call
Be honest with yourself about what you actually want.
Pros
- You already play on MC 1.12.2 and want a free, anarchy-focused client
- You want to read, build, or fork the source yourself
- You are fine running something that has not been updated in years, as long as it still works where you play
Cons
- No updates since the 1.12.2 era, so nothing new is coming
- You install Forge and drop the mod in yourself before you even reach a menu
- No launcher and no active support, and what documentation exists is thin
- Built for anarchy servers, not minigame combat, so it is the wrong tool if BedWars/SkyWars fights are the goal
If you want a client already tuned for BedWars/SkyWars-style fights, still getting updates for the Minecraft version you actually play, and $8.99 is not a decision that keeps you up at night, that is Opal. And if you are still on 1.12.2 anarchy servers and want to keep running something free and open source, Seppuku remains a fair, honest choice.
FAQ
No. It is documented as legacy, built for MC 1.12.2, with no ongoing updates.
No. Opal tracks the current release, MC 26.2, on Fabric and Java 25.
No. Opal is closed source. Seppuku is open source, which is a real reason to pick it if that matters to you.
Several of its modules were later reused by SalHack, a later client.
$8.99, one-time, no subscription.
Lifetime license, instant delivery, no subscription
Disclaimer
Independent comparison. Seppuku is a trademark of its owners; its use here is nominative and implies no affiliation or endorsement. Competitor details are accurate to the best of our knowledge as of 2026 and may contain errors.
