Flashback Server

Record your Paper/Folia server's gameplay into Flashback-format replays — entirely server-side. The players being recorded need no mods; you view the results with the Flashback client mod.

Features

Record any player server-side → .flashback files readable by the Flashback client.
Clip system — keep a rolling buffer per player and save the last N seconds on demand, or automatically when a player dies.
Folia-ready — works on the regionized Paper fork, no extra config.
Zero dependencies — pure Netty packet capture; no ProtocolLib to break on every update.
Renderable snapshots — recordings include a synthesized initial state (registries, chunks, player) so the Flashback client renders them from the start.
Multi-chunk recordings for long sessions + dimension changes.

Commands (`flashbackserver.replay`, default op)

Command	Description
`/replay start players <player>`	Start recording a player
`/replay stop players <player>`	Stop & save a recording
`/replay clip arm/disarm/save <player>`	Rolling clip buffer controls
`/replay verify <file>`	Decode-check a saved replay (diagnostic)
`/replay help`	Help

Configuration

clips.window-seconds (default 30) — rolling clip length.
clips.auto-clip-on-death (default true) — auto-save a clip when an armed player dies.
telemetry.enabled (default true) — anonymous, no-PII usage telemetry; set false to disable.

Install

Paper or a Paper fork (Purpur/Folia) for Minecraft 1.21.5–1.21.11.
Drop the jar in plugins/, restart. No dependencies.
View replays with the Flashback client mod.

Privacy

Anonymous, opt-out telemetry (server platform/version, recording/clip counts & sizes, error class names). No player names, UUIDs, or IPs are ever collected. Disable with telemetry.enabled: false.

Flashback Server is an independent project, not affiliated with or endorsed by the Flashback mod or its author. It produces files compatible with the Flashback format for interoperability.