UHP and HarnessRouter release tracker
Track protocol versions separately from HarnessRouter software releases and conformance-package revisions.
Page reviewed 4 Oct 2026 Source and review policy
Current coordinates
Section titled “Current coordinates”| Coordinate | Current state |
|---|---|
| UHP protocol | 2026-09-28 Draft |
| HarnessRouter stable | v0.29.1 |
| Stable release SHA | d257219281ef3b5a113fe8d8f2550ae0d12be320 |
| Conformance package | 2026.9.28.post3 |
| Executable checks | 85 |
| Released backends | 20 |
Separate an upgrade decision from release discovery
Section titled “Separate an upgrade decision from release discovery”When an upgrade spans several releases, use the dated update analysis to reconstruct which change introduced a behavior, then return to the release and implementation evidence for your installed version. A later suite or support matrix does not replace the denominator of an earlier measurement.
The stable release endpoint, rechecked 4 October, identifies v0.29.1 / d2572192. Development main was separately observed at the same d2572192 commit. The release listing also contains v0.30.0-rc.3, published earlier the same day as a prerelease; v0.29.1 remains the stable/Latest release.
| Change family | Before upgrading, verify |
|---|---|
| New backend/model | Required provider route and scenarios; upstream install/runtime policy |
| Runtime Plugin | Workspace inclusion, member authority and connection prerequisites |
| Environment protocol support | Advertised optional capability and metadata.environment request shape |
| Relay/artifact security fix | Targeted failure path plus affected authentication/delivery behavior |
| Conformance package change | Installed suite revision and a newly generated scoped report |
Pin the source/tag or container digest you intend to deploy, preserve its configuration/data recovery path, then validate the workflows affected by those changes. A protocol version can remain unchanged while implementation behavior changes materially. Conversely, optional Environments do not become mandatory merely because a server updates.
Treat release-note measurements as publisher evidence at the named build. Keep your deployment test receipt separate, including failures and untested paths. The conformance evidence remains revision-bounded; neither upgrading the executable package nor reading a new release note refreshes an older 74/74 report.
Key releases since v0.23.12
Section titled “Key releases since v0.23.12”v0.24.0 — Runtime Plugins
Section titled “v0.24.0 — Runtime Plugins”Published 25 Sep 2026 from 288a6dead48e114acd950f044f131d1212a733bf. PR #266 adds a Browser Use runtime service connected once per workspace and included per harness. See Runtime Plugins.
v0.25.0 — CheetahClaws
Section titled “v0.25.0 — CheetahClaws”Published 27 Sep 2026 from aab7597493b16f5ff12084d1f1400d3e7f4e46d5. PR #264 adds CheetahClaws 3.5.88 as backend sixteen. See CheetahClaws.
v0.26.x — UHP Environments
Section titled “v0.26.x — UHP Environments”PR #321 introduces UHP 2026-09-28 Environments. PR #331 patches task selection to metadata.environment, with schema, conformance and implementation moving together. Current package is 2026.9.28.post3 with 85 executable checks.
v0.26.18 — Sonnet 5.5 and Runtime Plugin availability
Section titled “v0.26.18 — Sonnet 5.5 and Runtime Plugin availability”Published 30 Sep 2026 at 21:33:01 UTC from 4fee4bcc4a4764e418b49d12d6d530a7de4b004f. PR #350 adds Claude Sonnet 5.5 coverage and removes the separate per-organization Runtime Plugin availability gate; PR #351 records the measured Sonnet 5.5 matrix.
v0.27.0 — Microsoft 365 Runtime Plugin
Section titled “v0.27.0 — Microsoft 365 Runtime Plugin”Published 1 Oct 2026 at 04:53:54 UTC from 31167726566186e4009790fe7e7ab7061ed99425. PR #343 adds Microsoft 365 through each organization’s Entra integration, with delegated calls bound to the signed-in workspace member.
v0.28.6 — public artifact sharing hardening
Section titled “v0.28.6 — public artifact sharing hardening”Published 2 Oct 2026 at 05:42:44 UTC from d80c540dcfd7ee8d09915fbedc12c8202ab9d527. PR #368 adds sandboxed public-artifact response policy and durable share-revocation revalidation.
v0.28.7 — GPT-6.1 Sol
Section titled “v0.28.7 — GPT-6.1 Sol”Published 2 Oct 2026 at 10:32:49 UTC from de674959316f6f2ef27be0f9407553f7552ace76. PR #369 adds GPT-6.1 Sol to the GPT-6 Sol-capable harness bases and records connection-specific measured coverage. It does not change the UHP protocol version.
v0.29.1 — current stable
Section titled “v0.29.1 — current stable”Published 4 Oct 2026 at 15:17:35 UTC from d257219281ef3b5a113fe8d8f2550ae0d12be320. PR #381 fixes provider-stream forwarding that could hold short responses behind a 4 KB read, and makes relay liveness depend on real provider events so comment-style keep-alive traffic cannot suppress HR_RELAY_UPSTREAM_TIMEOUT_S (600 seconds by default). The DeepSeek Harness relay takes the same rules. The release also fixes publication semantics so release candidates are marked prerelease and no longer take GitHub’s Latest badge. UHP remains 2026-09-28, conformance remains 2026.9.28.post3 / 85 checks, and the released backend count remains 20.
Publisher validation drove the real relay handlers over real sockets and reports 75 harness/model pairs on nine bases with 359/375 scenario runs, plus 14/14 family tours on DeepSeek Harness and Grok Build and 25/25 released-image checks on four bases. These are upstream release measurements, not this site’s independent provider run; the release explicitly says the relay defects were not caught on a live provider.
v0.29.0 — previous stable / backend expansion
Section titled “v0.29.0 — previous stable / backend expansion”Published 4 Oct 2026 at 00:33:05 UTC from 2826cf633b0588fa494da20fdf2828deacfb7e79. PR #373 adds Kilo CLI 7.8.1, MiniMax Code 0.5.4, Grok Build 1.0.41 and Agent Zero v2.13 as four new harness bases, taking the released backend set from 16 to 20. The same merge adds relay resilience and secret-handling hardening. UHP remains 2026-09-28 and conformance remains 2026.9.28.post3 / 85 checks.
Historical evidence
Section titled “Historical evidence”Historical conformance results remain tied to the source revision that produced them. A later check-count increase does not rewrite an earlier denominator.