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Service Upgrades

The LimaCharlie endpoint agent consists of two components that are versioned independently:

  • On-disk agent — the service binary installed on the host. It handles core identity, cryptography, and transport. This component rarely changes and is what gets replaced during a service upgrade.
  • Over-the-air core — the main functional component that delivers detection and response capabilities. It is downloaded from the LimaCharlie cloud and updated frequently. See Versioning & Upgrades for managing over-the-air updates.

The procedures on this page upgrade the on-disk agent only. This is useful when a new service binary is needed for bug fixes, platform compatibility, or to gain support for new on-disk features. Over-the-air core updates happen separately through the LimaCharlie cloud and do not require a service upgrade.

The upgrade process stops the running service, replaces the binary with the new version, and restarts the service. If the new version fails to start, an automatic rollback to the previous version occurs.

!!! note "Prerequisites" - The command must be run with root (Linux/macOS) or Administrator (Windows) privileges. - No installation key is required for upgrades.

Upgrade to Latest Version

curl -L --proto '=https' --tlsv1.2 -sSf https://downloads.limacharlie.io/sensor/posix/install | sudo sh -s -- --upgrade

irm https://downloads.limacharlie.io/sensor/windows/install.ps1 | iex; Upgrade-LCSensor

Upgrade or Downgrade to a Specific Version

The --version flag can be used to move to any available sensor version, whether newer or older than the currently installed version. This is useful for rolling back to a known-good version or pinning to a specific release.

Note

The --version flag requires sensor version 4.33.28 or later.

curl -L --proto '=https' --tlsv1.2 -sSf https://downloads.limacharlie.io/sensor/posix/install | sudo sh -s -- --upgrade --version 4.33.28

irm https://downloads.limacharlie.io/sensor/windows/install.ps1 | iex; Upgrade-LCSensor -Version "4.33.28"

Upgrade Using a Downloaded Sensor Binary

If you have already downloaded a sensor binary, you can upgrade the installed service directly by running it with the -u flag. This performs the same in-place upgrade without needing the shell installer.

Note

The -u flag requires sensor version 4.33.28 or later.

sudo ./hcp_linux_x64_release_4.33.28 -u

hcp_win_x64_release_4.33.28.exe -u

Upgrade from the Cloud with the upgrade_core Command (Beta)

Instead of running an installer on the host, you can task a sensor to upgrade its own on-disk agent with the upgrade_core sensor command. The sensor downloads, verifies, and installs the requested release itself — no local shell access or installer download is required. The automatic rollback on a failed start applies here as well.

The native upgrade procedure is currently in beta, so the --beta flag is required; the command is rejected without it.

limacharlie sensor task <SID> upgrade_core --beta

Optional flags:

  • --force: upgrade even if the sensor already reports the latest available release.
  • --version: pin the exact release to install (e.g. 5.3.3) instead of the latest; downgrades are allowed.

Note

The upgrade_core command requires sensor version 5.3.3 or later. Sensors running an older version silently drop the request and no upgrade takes place.

See the endpoint commands reference for more detail.

Advanced: Forcing an Upgrade

By default an in-place upgrade (-u) only replaces the installed service when the supplied binary is newer than what is installed. To re-apply or move to a build that is not strictly newer (for example to re-deploy a known-good version), set the LC_UPGRADE_SKIP_VERSION_CHECK environment variable to 1 (or true) on the upgrade process. This bypasses the version comparison and replaces the installed service unconditionally.

Warning

Use this only when you intend to override the version check. The automatic rollback on a failed start still applies, but skipping the check makes it possible to deliberately downgrade the on-disk agent.