systemd

aid: systemd
name: systemd
description: |
  systemd is a suite of basic building blocks for a Linux system. It runs as PID 1 and is the system and service
  manager that bootstraps the rest of the userspace, supervises long-running services, and exposes a coordinated
  set of D-Bus and Varlink IPC interfaces for managing services (systemd1), users and sessions (logind),
  network interfaces (networkd), name resolution (resolved), containers/VMs (machined), home directories
  (homed), boot entries (boot1/sysupdate1), system hostname/locale/timedate, OOM protection (oomd), portable
  services, and image imports. The project also publishes a stable command-line surface (systemctl,
  journalctl, networkctl, resolvectl, loginctl, machinectl, hostnamectl, timedatectl, localectl, busctl,
  varlinkctl, bootctl, homectl, coredumpctl, oomctl, portablectl, importctl, systemd-analyze and more).
  systemd is dual-licensed (LGPL-2.1-or-later for libraries and most code, GPL-2.0-or-later for select tools)
  and developed openly on GitHub at systemd/systemd.
type: Index
position: Consumer
access: 3rd-Party
image: https://systemd.io/assets/systemd-logo.svg
tags:
  - Boot
  - Cgroups
  - Container
  - D-Bus
  - Init
  - IPC
  - Journal
  - Linux
  - Logging
  - Network
  - Open Source
  - PID 1
  - Service Manager
  - System
  - Systemd
  - Varlink
created: '2026-05-23'
modified: '2026-05-23'
url: https://raw.githubusercontent.com/api-evangelist/systemd/refs/heads/main/apis.yml
specificationVersion: '0.19'
apis:
  - aid: systemd:org-freedesktop-systemd1
    name: systemd Manager (org.freedesktop.systemd1)
    description: |
      Core D-Bus API exposed by PID 1 on the system bus. The Manager object at /org/freedesktop/systemd1
      enumerates and controls units (services, sockets, mounts, targets, timers, paths, slices, scopes, swaps,
      devices), starts and stops jobs, loads/reloads configuration, manages cgroup-backed transient units, and
      emits lifecycle signals (UnitNew, UnitRemoved, JobNew, JobRemoved, Reloading, StartupFinished). Per-unit
      interfaces (Unit, Service, Socket, Mount, Slice, Scope, Path, Swap, Timer, Target) expose state,
      properties, and operations on individual units.
    humanURL: https://www.freedesktop.org/software/systemd/man/latest/org.freedesktop.systemd1.html
    baseURL: dbus:org.freedesktop.systemd1
    tags:
      - Cgroups
      - D-Bus
      - Service Manager
      - Systemd
      - Units
    properties:
      - type: Documentation
        url: https://www.freedesktop.org/software/systemd/man/latest/org.freedesktop.systemd1.html
      - type: InterfaceDefinition
        url: https://github.com/systemd/systemd/blob/main/man/org.freedesktop.systemd1.xml
      - type: OpenAPI
        url: openapi/systemd1-openapi.yml
  - aid: systemd:org-freedesktop-login1
    name: systemd-logind (org.freedesktop.login1)
    description: |
      D-Bus API of systemd-logind for tracking user logins, seats, sessions, and inhibitor locks. Manages
      session creation, switching, idle hints, lock/unlock, power-button handling, lid-switch handling,
      suspend/hibernate/reboot/power-off operations, and ACLs for hot-pluggable devices.
    humanURL: https://www.freedesktop.org/software/systemd/man/latest/org.freedesktop.login1.html
    baseURL: dbus:org.freedesktop.login1
    tags:
      - D-Bus
      - Logind
      - Sessions
      - Users
    properties:
      - type: Documentation
        url: https://www.freedesktop.org/software/systemd/man/latest/org.freedesktop.login1.html
      - type: InterfaceDefinition
        url: https://github.com/systemd/systemd/blob/main/man/org.freedesktop.login1.xml
      - type: OpenAPI
        url: openapi/login1-openapi.yml
  - aid: systemd:org-freedesktop-network1
    name: systemd-networkd (org.freedesktop.network1)
    description: |
      D-Bus API of systemd-networkd for managing network interfaces, link configuration, DHCP server state,
      and netdev/network unit reload. Exposes Manager and per-Link interfaces with methods to set link
      properties, reconfigure, force renew, and query link state.
    humanURL: https://www.freedesktop.org/software/systemd/man/latest/org.freedesktop.network1.html
    baseURL: dbus:org.freedesktop.network1
    tags:
      - D-Bus
      - DHCP
      - Network
      - Networkd
    properties:
      - type: Documentation
        url: https://www.freedesktop.org/software/systemd/man/latest/org.freedesktop.network1.html
      - type: InterfaceDefinition
        url: https://github.com/systemd/systemd/blob/main/man/org.freedesktop.network1.xml
      - type: OpenAPI
        url: openapi/network1-openapi.yml
  - aid: systemd:org-freedesktop-resolve1
    name: systemd-resolved (org.freedesktop.resolve1)
    description: |
      D-Bus API of systemd-resolved for DNS/mDNS/LLMNR resolution, DNSSEC validation, per-link DNS
      configuration, search domain management, DNS-over-TLS settings, and cache flushing. Exposes
      ResolveHostname, ResolveAddress, ResolveRecord, ResolveService and per-Link configuration methods.
    humanURL: https://www.freedesktop.org/software/systemd/man/latest/org.freedesktop.resolve1.html
    baseURL: dbus:org.freedesktop.resolve1
    tags:
      - D-Bus
      - DNS
      - DNSSEC
      - Resolved
    properties:
      - type: Documentation
        url: https://www.freedesktop.org/software/systemd/man/latest/org.freedesktop.resolve1.html
      - type: InterfaceDefinition
        url: https://github.com/systemd/systemd/blob/main/man/org.freedesktop.resolve1.xml
      - type: OpenAPI
        url: openapi/resolve1-openapi.yml
  - aid: systemd:org-freedesktop-machine1
    name: systemd-machined (org.freedesktop.machine1)
    description: |
      D-Bus API of systemd-machined for tracking and managing local containers and virtual machines,
      enumerating their associated images, opening shells/login sessions inside them, copying files in/out,
      and binding mounts across container boundaries.
    humanURL: https://www.freedesktop.org/software/systemd/man/latest/org.freedesktop.machine1.html
    baseURL: dbus:org.freedesktop.machine1
    tags:
      - Containers
      - D-Bus
      - Machined
      - VMs
    properties:
      - type: Documentation
        url: https://www.freedesktop.org/software/systemd/man/latest/org.freedesktop.machine1.html
      - type: InterfaceDefinition
        url: https://github.com/systemd/systemd/blob/main/man/org.freedesktop.machine1.xml
      - type: OpenAPI
        url: openapi/machine1-openapi.yml
  - aid: systemd:org-freedesktop-hostname1
    name: systemd-hostnamed (org.freedesktop.hostname1)
    description: |
      D-Bus API of systemd-hostnamed for getting and setting the system hostname (static, transient, pretty),
      deployment/location/icon metadata, chassis type, and machine info.
    humanURL: https://www.freedesktop.org/software/systemd/man/latest/org.freedesktop.hostname1.html
    baseURL: dbus:org.freedesktop.hostname1
    tags:
      - D-Bus
      - Hostname
      - Hostnamed
    properties:
      - type: Documentation
        url: https://www.freedesktop.org/software/systemd/man/latest/org.freedesktop.hostname1.html
      - type: InterfaceDefinition
        url: https://github.com/systemd/systemd/blob/main/man/org.freedesktop.hostname1.xml
      - type: OpenAPI
        url: openapi/hostname1-openapi.yml
  - aid: systemd:org-freedesktop-locale1
    name: systemd-localed (org.freedesktop.locale1)
    description: |
      D-Bus API of systemd-localed for getting and setting the system locale, X11 keymap, and console keymap.
    humanURL: https://www.freedesktop.org/software/systemd/man/latest/org.freedesktop.locale1.html
    baseURL: dbus:org.freedesktop.locale1
    tags:
      - D-Bus
      - Locale
      - Localed
    properties:
      - type: Documentation
        url: https://www.freedesktop.org/software/systemd/man/latest/org.freedesktop.locale1.html
      - type: InterfaceDefinition
        url: https://github.com/systemd/systemd/blob/main/man/org.freedesktop.locale1.xml
  - aid: systemd:org-freedesktop-timedate1
    name: systemd-timedated (org.freedesktop.timedate1)
    description: |
      D-Bus API of systemd-timedated for getting and setting the system time, timezone, NTP enablement, and
      RTC-in-local-time policy.
    humanURL: https://www.freedesktop.org/software/systemd/man/latest/org.freedesktop.timedate1.html
    baseURL: dbus:org.freedesktop.timedate1
    tags:
      - D-Bus
      - NTP
      - Time
      - Timedated
    properties:
      - type: Documentation
        url: https://www.freedesktop.org/software/systemd/man/latest/org.freedesktop.timedate1.html
      - type: InterfaceDefinition
        url: https://github.com/systemd/systemd/blob/main/man/org.freedesktop.timedate1.xml
  - aid: systemd:org-freedesktop-timesync1
    name: systemd-timesyncd (org.freedesktop.timesync1)
    description: |
      D-Bus API of systemd-timesyncd exposing the current NTP server, peers, root delay/dispersion, and
      synchronization status.
    humanURL: https://www.freedesktop.org/software/systemd/man/latest/org.freedesktop.timesync1.html
    baseURL: dbus:org.freedesktop.timesync1
    tags:
      - D-Bus
      - NTP
      - SNTP
      - Timesyncd
    properties:
      - type: Documentation
        url: https://www.freedesktop.org/software/systemd/man/latest/org.freedesktop.timesync1.html
      - type: InterfaceDefinition
        url: https://github.com/systemd/systemd/blob/main/man/org.freedesktop.timesync1.xml
  - aid: systemd:org-freedesktop-home1
    name: systemd-homed (org.freedesktop.home1)
    description: |
      D-Bus API of systemd-homed for managing portable, encrypted user home directories (LUKS, btrfs subvol,
      fscrypt, CIFS, directory) including create/remove/update/list operations, activation, authentication,
      and rebalancing.
    humanURL: https://www.freedesktop.org/software/systemd/man/latest/org.freedesktop.home1.html
    baseURL: dbus:org.freedesktop.home1
    tags:
      - D-Bus
      - Home Directories
      - Homed
      - LUKS
    properties:
      - type: Documentation
        url: https://www.freedesktop.org/software/systemd/man/latest/org.freedesktop.home1.html
      - type: InterfaceDefinition
        url: https://github.com/systemd/systemd/blob/main/man/org.freedesktop.home1.xml
  - aid: systemd:org-freedesktop-import1
    name: systemd-importd (org.freedesktop.import1)
    description: |
      D-Bus API of systemd-importd for importing, exporting, downloading, listing, and removing container/VM
      machine images (tar, raw, dkr/OCI, qcow2) used by machined and portable services.
    humanURL: https://www.freedesktop.org/software/systemd/man/latest/org.freedesktop.import1.html
    baseURL: dbus:org.freedesktop.import1
    tags:
      - Containers
      - D-Bus
      - Images
      - Importd
    properties:
      - type: Documentation
        url: https://www.freedesktop.org/software/systemd/man/latest/org.freedesktop.import1.html
      - type: InterfaceDefinition
        url: https://github.com/systemd/systemd/blob/main/man/org.freedesktop.import1.xml
  - aid: systemd:org-freedesktop-oom1
    name: systemd-oomd (org.freedesktop.oom1)
    description: |
      D-Bus API of systemd-oomd, the userspace out-of-memory killer that uses cgroup v2 PSI signals to kill
      cgroups under memory or swap pressure. Exposes per-slice/cgroup state and policy.
    humanURL: https://www.freedesktop.org/software/systemd/man/latest/org.freedesktop.oom1.html
    baseURL: dbus:org.freedesktop.oom1
    tags:
      - Cgroups
      - D-Bus
      - OOM
      - Oomd
      - PSI
    properties:
      - type: Documentation
        url: https://www.freedesktop.org/software/systemd/man/latest/org.freedesktop.oom1.html
      - type: InterfaceDefinition
        url: https://github.com/systemd/systemd/blob/main/man/org.freedesktop.oom1.xml
  - aid: systemd:org-freedesktop-portable1
    name: systemd-portabled (org.freedesktop.portable1)
    description: |
      D-Bus API of systemd-portabled for attaching/detaching portable service images, listing attached
      images, inspecting them, and managing their lifecycle on the host.
    humanURL: https://www.freedesktop.org/software/systemd/man/latest/org.freedesktop.portable1.html
    baseURL: dbus:org.freedesktop.portable1
    tags:
      - D-Bus
      - Portable Services
      - Portabled
    properties:
      - type: Documentation
        url: https://www.freedesktop.org/software/systemd/man/latest/org.freedesktop.portable1.html
      - type: InterfaceDefinition
        url: https://github.com/systemd/systemd/blob/main/man/org.freedesktop.portable1.xml
  - aid: systemd:org-freedesktop-sysupdate1
    name: systemd-sysupdated (org.freedesktop.sysupdate1)
    description: |
      D-Bus API of systemd-sysupdated for transactional A/B updates of system/host/portable/container images
      using systemd-sysupdate transfers, including target enumeration, version listing, and update jobs.
    humanURL: https://www.freedesktop.org/software/systemd/man/latest/org.freedesktop.sysupdate1.html
    baseURL: dbus:org.freedesktop.sysupdate1
    tags:
      - A/B Updates
      - D-Bus
      - Sysupdated
      - System Updates
    properties:
      - type: Documentation
        url: https://www.freedesktop.org/software/systemd/man/latest/org.freedesktop.sysupdate1.html
      - type: InterfaceDefinition
        url: https://github.com/systemd/systemd/blob/main/man/org.freedesktop.sysupdate1.xml
  - aid: systemd:org-freedesktop-logcontrol1
    name: LogControl1 (org.freedesktop.LogControl1)
    description: |
      Generic D-Bus interface that systemd daemons (and other services) implement to expose runtime log
      level and log target configuration. Allows tools like systemd-analyze to change verbosity without
      restart.
    humanURL: https://www.freedesktop.org/software/systemd/man/latest/org.freedesktop.LogControl1.html
    baseURL: dbus:org.freedesktop.LogControl1
    tags:
      - D-Bus
      - Logging
      - Observability
    properties:
      - type: Documentation
        url: https://www.freedesktop.org/software/systemd/man/latest/org.freedesktop.LogControl1.html
      - type: InterfaceDefinition
        url: https://github.com/systemd/systemd/blob/main/man/org.freedesktop.LogControl1.xml
  - aid: systemd:io-systemd-varlink
    name: systemd Varlink Interfaces (io.systemd.*)
    description: |
      Modern JSON-line IPC surface exposed by systemd daemons via Varlink (single-fd, self-describing,
      discoverable through `varlinkctl`). Covers ~39 interfaces including io.systemd.Manager, io.systemd.Unit,
      io.systemd.Job, io.systemd.Login, io.systemd.Machine, io.systemd.Machine.Image,
      io.systemd.MachineInstance, io.systemd.VirtualMachineInstance, io.systemd.Network,
      io.systemd.Network.Link, io.systemd.Resolve, io.systemd.Resolve.Hook, io.systemd.Resolve.Monitor,
      io.systemd.Journal, io.systemd.JournalAccess, io.systemd.Hostname, io.systemd.BootControl,
      io.systemd.Credentials, io.systemd.FactoryReset, io.systemd.Import, io.systemd.InstanceMetadata,
      io.systemd.AskPassword, io.systemd.Metrics, io.systemd.ManagedOOM, io.systemd.MountFileSystem,
      io.systemd.MuteConsole, io.systemd.NamespaceResource, io.systemd.PCRExtend, io.systemd.PCRLock,
      io.systemd.Repart, io.systemd.Shutdown, io.systemd.StorageProvider, io.systemd.Udev,
      io.systemd.UserDatabase, io.systemd.oom, io.systemd.oom.Prekill, io.systemd.service, io.systemd.sysext.
    humanURL: https://systemd.io/USER_GROUP_API/
    baseURL: varlink:io.systemd
    tags:
      - IPC
      - JSON
      - Varlink
    properties:
      - type: Documentation
        url: https://www.freedesktop.org/software/systemd/man/latest/varlinkctl.html
      - type: SourceCode
        url: https://github.com/systemd/systemd/tree/main/src
      - type: OpenAPI
        url: openapi/varlink-openapi.yml
common:
  - type: Website
    url: https://systemd.io
  - type: Documentation
    url: https://www.freedesktop.org/software/systemd/man/latest/
  - type: GitHubOrganization
    url: https://github.com/systemd
  - type: GitHubRepository
    url: https://github.com/systemd/systemd
  - type: SourceCode
    url: https://github.com/systemd/systemd
  - type: License
    url: https://github.com/systemd/systemd/blob/main/LICENSES/LGPL-2.1-or-later.txt
  - type: License
    url: https://github.com/systemd/systemd/blob/main/LICENSES/GPL-2.0-or-later.txt
  - type: ReleaseNotes
    url: https://github.com/systemd/systemd/releases
  - type: ChangeLog
    url: https://github.com/systemd/systemd/blob/main/NEWS
  - type: IssueTracker
    url: https://github.com/systemd/systemd/issues
  - type: PullRequests
    url: https://github.com/systemd/systemd/pulls
  - type: MailingList
    url: https://lists.freedesktop.org/mailman/listinfo/systemd-devel
  - type: Mastodon
    url: https://mastodon.social/@pid_eins
  - type: Tool
    url: https://www.freedesktop.org/software/systemd/man/latest/systemctl.html
  - type: Tool
    url: https://www.freedesktop.org/software/systemd/man/latest/journalctl.html
  - type: Tool
    url: https://www.freedesktop.org/software/systemd/man/latest/networkctl.html
  - type: Tool
    url: https://www.freedesktop.org/software/systemd/man/latest/resolvectl.html
  - type: Tool
    url: https://www.freedesktop.org/software/systemd/man/latest/loginctl.html
  - type: Tool
    url: https://www.freedesktop.org/software/systemd/man/latest/machinectl.html
  - type: Tool
    url: https://www.freedesktop.org/software/systemd/man/latest/hostnamectl.html
  - type: Tool
    url: https://www.freedesktop.org/software/systemd/man/latest/timedatectl.html
  - type: Tool
    url: https://www.freedesktop.org/software/systemd/man/latest/localectl.html
  - type: Tool
    url: https://www.freedesktop.org/software/systemd/man/latest/busctl.html
  - type: Tool
    url: https://www.freedesktop.org/software/systemd/man/latest/varlinkctl.html
  - type: Tool
    url: https://www.freedesktop.org/software/systemd/man/latest/bootctl.html
  - type: Tool
    url: https://www.freedesktop.org/software/systemd/man/latest/homectl.html
  - type: Tool
    url: https://www.freedesktop.org/software/systemd/man/latest/coredumpctl.html
  - type: Tool
    url: https://www.freedesktop.org/software/systemd/man/latest/oomctl.html
  - type: Tool
    url: https://www.freedesktop.org/software/systemd/man/latest/portablectl.html
  - type: Tool
    url: https://www.freedesktop.org/software/systemd/man/latest/importctl.html
  - type: Tool
    url: https://www.freedesktop.org/software/systemd/man/latest/systemd-analyze.html
  - type: SDK
    url: https://www.freedesktop.org/software/systemd/man/latest/sd-bus.html
  - type: SDK
    url: https://www.freedesktop.org/software/systemd/man/latest/sd-varlink.html
  - type: SDK
    url: https://www.freedesktop.org/software/systemd/man/latest/sd-journal.html
  - type: SDK
    url: https://www.freedesktop.org/software/systemd/man/latest/sd-event.html
  - type: Vocabulary
    url: vocabulary/systemd-vocabulary.yml
  - type: JSONLD
    url: json-ld/systemd-context.jsonld
license: LGPL-2.1-or-later AND GPL-2.0-or-later
maintainer:
  FN: systemd developers
  email: systemd-devel@lists.freedesktop.org
  url: https://lists.freedesktop.org/mailman/listinfo/systemd-devel