generated: '2026-07-21'
method: searched
source: https://docs.urbit.org/ + https://github.com/urbit/vere/releases
description: >-
  Lifecycle posture for the Urbit platform. Versioning is two-track: the Vere
  runtime releases as vere-vX.Y; the Arvo kernel uses Kelvin versioning,
  counting DOWN toward absolute zero (410 -> 409k -> 408k) with the explicit
  goal of a frozen, permanent kernel at 0K. Breaking kernel changes arrive as
  Kelvin decrements with published migration workflows (urbit.org's
  urbit-development skill ships kelvin-migrations references such as 409k to
  408k). No public status page, SLA, or RFC 8594 Sunset/Deprecation header
  support was found (probed status.urbit.org: unreachable; roadmap.urbit.org
  and urbit.org/roadmap: 404). Every desk pins compatible kernel versions in
  sys.kelvin (e.g. [%zuse 410]).
versioning:
  kernel:
    scheme: kelvin (counts down toward 0K; frozen forever at absolute zero)
    current: 408k
    compatibility: desks declare supported kernel versions in sys.kelvin
    docs: https://docs.urbit.org/build-on-urbit/environment#create-a-new-desk
  runtime:
    scheme: vere-vX.Y GitHub releases
    current: vere-v4.6
    releases: https://github.com/urbit/vere/releases
migration:
  policy: >-
    Kelvin decrements are the breaking-change vehicle; app developers follow
    published Kelvin migration workflows (e.g. 409k -> 408k) to move desks
    across kernel versions.
  docs: https://urbit.org/.agents/skills/urbit-development/SKILL.md
deprecation:
  policy_url: null
  sunset_header: false
  notes: No standalone deprecation policy or RFC 8594 header support documented.
sla: null
status_page: null
probes:
  - url: https://status.urbit.org/
    status: unreachable
  - url: https://roadmap.urbit.org/
    status: 404
  - url: https://urbit.org/roadmap
    status: 404