Client Brand
Lunar Client can be detected by checking the Minecraft client brand sent to the server. This allows you to detect and track Lunar Client players, if you're unable to use the full Apollo integration.
This is not a cryptographically secure detection method. Malicious clients can spoof the client brand sent to the server.
Brand Format
The client brand is sent as a comma-delimited list of identifiers. For example: lunarclient:<VERSION>,fabric
The first identifier is always lunarclient:<VERSION>, where <VERSION> is the Lunar Client build that the user is running. Additional identifiers may be appended to indicate other mod loaders or relevant context. See the next section for info about the version format.
Format Change: As of 1st December 2025, the client brand was sent as a single string (lunarclient:<VERSION>). This change aligns the Lunar Client brand format with other modern mod loaders such as Fabric and Forge, improving compatibility with mods and plugins that rely on client branding to detect mod loaders.
Version Format
We do not provide any guarantees about the exact format of the version, and it may change without notice. An unexpected version format does not mean that a user is running an unofficial build of Lunar Client. The version will be visible on the Minecraft F3 menu, and in the window title, in addition to being present in the client brand.
Most, but not all, users will have a version in the format of v<MAJOR>.<MINOR>.<PATCH>-<RELEASE YEAR><RELEASE WEEK>. For example, v2.12.0-2349 is version v2.12.0, which
was built in the 49th week of 2023.