OpLimitBypass

About

Vanilla lets an operator with bypassesPlayerLimit join a full server, but once connected they still occupy one of the max-players slots. On a server with a cap of 20, three such operators leave room for only 17 other players.

OpLimitBypass excludes them from the count, so the cap applies to everyone else exactly as configured. With max-players=20, twenty players plus three bypassing operators can be online at once. Whitelist and ban checks are untouched.

This is a server-side mod. Clients do not need to install it.

Features

Player limit

• Operators with bypassesPlayerLimit no longer occupy a slot
• The reported player count matches the rule being enforced, so a full server never advertises 23/20
• max-players can be changed at runtime without a restart

Maintenance mode

• Closes the server to everyone except bypassing operators and a named allow list
• Disconnects players who are no longer permitted, and reports 0/0 with a maintenance MOTD
• The allow list is stored in oplimit-maintenance.json and survives a restart

Operator flag management

• Reads and writes bypassesPlayerLimit in ops.json directly, applied immediately
• Vanilla only reads ops.json at startup and offers no command for this flag

Localisation

• English and Japanese
• Messages are sent as translation keys with a server-resolved fallback, so clients render their own language where possible

Commands

All commands require permission level 4.

Running /oplimit with no arguments shows the status.

Requirements

Forge 1.20.1 bundles Mixin, so no extra dependency is needed there.

Notes

• While maintenance mode is on, the server reports 0/0: players who are still permitted do not occupy a slot either.
• Maintenance mode itself is held in memory. Restarting the server leaves maintenance mode, and max-players returns to the value in server.properties. The allow list is unaffected.
• Enabling maintenance mode disconnects the operator running the command unless they are permitted to stay. Running it from the console is unaffected.
• When only bypassing operators are online the reported count is 0, which matters if you also run a mod that idles the server at zero players.
• On 1.12.2, /list takes its count from this mod but still names every player, so the two can disagree.
• On 1.12.2, running /op or /deop rewrites ops.json with vanilla's view of the flag. Re-apply with /oplimit bypass <player> true afterwards.

Source

Source, issue tracker and full documentation: GitHub