One JAR for every platform
ReplayCore ships as a single, self-contained JAR (`ReplayCore-<version>.jar`). The same file is what you install whether you run Paper 1.8.8 or Paper 26.2, so you never have to pick a platform-specific build by hand.
On Paper, Purpur and Folia, official PacketEvents 2.13.0+ must already be in the server plugins folder. Recording stays idle until it is present. Download it from Modrinth (https://modrinth.com/plugin/packetevents) or GitHub releases (https://github.com/retrooper/packetevents/releases). Spigot 1.8.8 does not need this step.
The ReplayCore JAR bundles the full recording engine. There is no separate ReplayCore implementation file to fetch and no plugins/ReplayCore/lib/ directory to manage.
How platform detection works
On first start the plugin inspects the running server to determine the platform (Paper, Purpur, Spigot) and Minecraft version. It then activates the bundled recording engine that matches your environment, the legacy engine for 1.8.8 or the modern engine for 1.13 and above, all from inside the one JAR.
No network call is needed to load the bundled classes. Before recording starts, ReplayCore authenticates, verifies or establishes the private server binding and retrieves the managed configuration described in the Licence activation article.
Offline and air-gapped servers
Because the recording engine ships inside the JAR, a server with no internet access at boot can still load the plugin classes. A fresh install cannot authenticate or retrieve its managed policy, so ReplayCore fails closed and records nothing while the Minecraft server keeps running. A previously verified install may continue only while its matching authenticated grace and last-known-good state remain eligible.
If the JAR itself fails to load (for example after an interrupted download leaves a truncated file), delete it from plugins/, download a fresh copy from the Downloads page of your dashboard, and restart.