Published in openvibe-contracts v0.33.0 (docs/adr/ADR-016-active-client-updates.md), rendered as is.

ADR-016: Active client update safety and the supported mixed-version window

Status: Accepted 2026-09-23. Governs Track R.

Context and current evidence

Live serves content-hashed asset URLs (server/web/assets.js) and posts one rolling deploy notice in chat.
/shared/* on Network is served from the pinned OpenVibe.Shared release:
plain URLs carry max-age=300;
?v=<hash> and /shared/v1/* URLs are immutable for a year.
Cloudflare currently raises short browser TTLs to 4 hours, a zone setting that needs changing to "respect existing headers".
Open tabs can run a client built several releases ago against a new server.

Mixed-version window: a server supports clients from the current and the previous release of its API contract for at least 24 hours after a deploy, and never breaks a contract version inside its major (ADR-002).
Assets: every asset a page loads is either content-hash addressed (immutable) or explicitly short-lived. An HTML document never references a mutable URL for code.
Release manifest: each web surface serves /release.json (service, release id, contract versions, min supported client release). Clients compare on focus/reconnect. When they have fallen outside the window, they show a non-blocking "new version" prompt, and reload automatically only when idle with no unsent input, upload, call or stream.
Protected sessions: a deploy never ends an upload, a call, a live broadcast or a recording. Host (Wave 21) drains or waits, as Live's --wait-idle does today.
Shared chrome: a release of OpenVibe.Shared must not break a page that pinned the previous minor.

Forced reload on deploy: rejected; it loses input and interrupts sessions.
Service workers for version pinning: deferred; the release manifest is enough and is simpler to reason about.

Live, Network, Community, Media and Tools add /release.json. The Cloudflare browser-TTL setting is changed so origin cache headers are respected.

The manifest is advisory; removing it returns clients to today's behaviour.