Start from a preset
Ritual charge, Raid phase II, Evacuation: 3 minutes and Phase break incoming fill every field with a typical event. Change the ID before using one, so two events never share a bar.
Minecraft Bossbar Builder
Create bossbar command stacks for roleplay events, raids, rituals, countdowns, and server-wide warnings. Pick an ID, title, color, style, players, and progress value, then copy a clean sequence for command blocks or datapack functions.
Quick presets
Bossbar setup
Bossbars are strongest when they show state: danger, ritual charge, phase progress, evacuation time, or public server pressure. This builder creates the setup commands; live timers still need repeating command blocks or datapack functions to update the value.
Generated commands
How to use the builder
The builder writes seven /bossbar commands: one creates the bar, six set it up. The preview shows the title, color and fill before you copy anything.
Name it twice
The ID, for example cube:ritual_charge, is how later commands find the bar; it is lowercase and gets the cube: namespace if you leave one out. The title is what players read, drawn small above the bar, so keep it to a few words.
Color and style
Use progress for timers and anything continuous, and a notched style when players should be able to count phases. Pick a notch count that your maximum divides into evenly.
Max, value and players
Max and value share one unit: seconds, phases, offerings. Players decides who sees the bar right now; someone who logs in later sees nothing until that line runs again.
Copy and run
Paste the lines into chat one at a time to test, into command blocks one per block, or into a function file without the leading slash.
Three things the output cannot do for you
Run twice
The add line fails if the ID already exists. To rebuild a bar, run /bossbar remove first or skip the first line.
Count down
A bar shows the last value it was given. A timer needs a loop that keeps updating it; the event article has a working countdown.
Clean up
Custom bars are saved with the world and survive restarts. Run /bossbar remove when the scene ends and /bossbar list to catch leftovers.
Versions
Java Edition 1.13 to 26.3. The title is written as {"text":"…","color":"white"}: Minecraft reads it as JSON up to 1.21.4 and as SNBT from 1.21.5, so the same output works on both. Bedrock Edition has no /bossbar command.