Skip to content
UHPUHPDeveloper Guide
Independent resource · Not affiliated with HarnessRouter · Site data checked 24 Sep 2026

Adoption tracker

UHP adoption tracker

Verified implementation facts are separated from native vendor adoption, third-party UHP servers and claims that still lack independent evidence.

Verified: Protocol: 2026-09-12Static SSG

Current adoption status

Section titled “Current adoption status”
ClaimStatusEvidence boundary
UHP specification existsVerifiedPublished protocol is 2026-09-12 Draft.
HarnessRouter CE implements UHPVerifiedReference implementation; stable/current main is v0.23.12 / 5c2d3bb3.
Current conformance sourceVerified75 checks, package 2026.9.12.post2. PR #217 changes installed schema packaging; PR #260 corrects standards-valid SSE parsing in the suite client. Neither changes protocol semantics, verdict classes or the denominator.
HarnessRouter released backend supportVerified implementation15 backends: the prior thirteen plus OpenHands (v0.20.0) and System One (v0.21.0).
Explicit HarnessRouter target resolution fails closedVerified implementationv0.23.10 / PR #252: an explicit unknown/deleted harness id returns 404 harness_not_found instead of falling through to the default backend; built-in base ids and omitted ids retain their intended paths.
HarnessRouter public OpenAPI excludes console-only routesVerified implementationv0.23.11 / PR #254: the public schema honors FastAPI include_in_schema=False; fifteen console/kits handlers under public-looking prefixes are excluded while protocol routes under the same prefix remain included.
HarnessRouter conformance client accepts standards-valid SSE framingVerified implementationv0.23.12 / PR #260: LF, CRLF and CR line endings plus multi-line data: fields are parsed according to SSE framing, removing false negatives against valid servers; this does not add a UHP check or upgrade an implementation measurement.
OpenHands is a HarnessRouter backendVerified implementationPR #215; current adapter defaults to agent-server/tools/SDK 1.49.2.
OpenHands natively implements UHPNot establishedReviewed OpenHands primary sources do not publish native UHP server support.
System One is a HarnessRouter backendVerified implementationPR #225; current HarnessRouter pin is System One 0.4.0.
System One natively implements UHPNot establishedIts finite action loop and dual-loop calibration architecture are distinct from UHP server adoption.
Scoped dual-loop calibration exists in HarnessRouterVerified implementationPR #232 / v0.23.0: one calibrator may drive one declared target through a short-lived target-scoped credential.
Aider is a HarnessRouter backendVerified implementationPR #211 / v0.19.0; adapter-owned MCP bridge and pinned Python seam.
Native UHP support by HarnessRouter backend vendorsNot establishedBackend support proves HarnessRouter can drive those runtimes; it does not prove upstream UHP adoption.
Independent non-HarnessRouter UHP servers existVerified implementationaenawi/uhp-go and SuperQode provide separate server evidence.
SuperQode measured conformanceVerified CoreHistorical Full-requested report 42/74, with all 40 Core checks passing; revision-bounded.
Historical HarnessRouter checked Full evidenceVerified and revision-boundedPR #175/#178/#190 preserve 74/74 Full evidence for the pre-X-09 source.
Later HarnessRouter 75/75 evidenceVerified candidate runPR #211 reports 75/75 for the source released as v0.19.0; not a replacement checked versioned report.
Cross-server client interoperabilityNot establishedNo reviewed primary evidence demonstrates the same independent UHP client across multiple independently maintained servers.

The 23–24 September release train expands implementation support and fidelity, not native adoption

Section titled “The 23–24 September release train expands implementation support and fidelity, not native adoption”

HarnessRouter advanced from the previously tracked v0.19.0 line to v0.23.12 while UHP remained 2026-09-12.

The meaningful adoption classification changes are limited:

  • OpenHands becomes a verified HarnessRouter backend in v0.20.0.
  • System One becomes a verified HarnessRouter backend in v0.21.0.
  • The released backend count therefore rises from 13 to 15.
  • System One’s direct TypeSafe provider and later dual-loop calibration increase HarnessRouter capability, not UHP vendor adoption.
  • v0.23.x environment/secrets, kit, model-catalog and runtime fixes likewise do not create new native-UHP rows.
  • v0.23.10 / PR #252 hardens explicit target identity: a typoed/deleted explicit harness id no longer executes through a generic/default backend. This changes HarnessRouter dispatch safety, not adoption status or the UHP protocol.
  • v0.23.11 / PR #254 corrects the public OpenAPI boundary so console-only handlers do not appear as customer-facing API surface; PR #257 and #253 separately improve live terminal-detail rendering and benchmark trace retention. None creates a new backend, conformance claim or upstream UHP adoption row.
  • v0.23.12 / PR #260 corrects the measurement client so valid CRLF/CR/multi-line SSE is not falsely rejected and advances package metadata to 2026.9.12.post2; PR #258 rejects deterministic chain/provider mismatches before execution and stops retrying non-429 runner 4xx verdicts. Neither creates native adoption or changes UHP.

The durable distinction is that HarnessRouter adapter support is an implementation fact; native UHP adoption requires the upstream project itself to name and implement UHP. Reviewed primary sources still do not establish native UHP adoption by the 15 upstream harness projects represented in current HarnessRouter.

Conformance package revisions do not upgrade adoption claims

Section titled “Conformance package revisions do not upgrade adoption claims”

PR #217, released in v0.19.1, ensures an installed uhp-conformance package contains the exact canonical schema and can run schema-backed checks outside a repository checkout. Package metadata became 2026.9.12.post1, with 75 checks still in the suite.

PR #260, released in v0.23.12, advances package metadata to 2026.9.12.post2 because the suite client now follows standards-valid SSE framing: LF, CRLF or CR line endings and multi-line data: fields. The check set remains 75, UHP remains 2026-09-12, and older checked/candidate measurements remain tied to the source/package state they actually ran.

These changes improve measurement fidelity; they do not upgrade any implementation’s prior measured class or rewrite historical evidence.

Independent implementation status

Section titled “Independent implementation status”
  • HarnessRouter CE/Cloud: verified UHP implementations.
  • SuperQode: client + server; measured Core on a historical 74-check source.
  • uhp-go: separately maintained Go server/client with 63/63 Full evidence for its pinned earlier suite.
  • AIWG and mini-ork: independent client-side implementation evidence.

A future adoption upgrade should be tied to direct upstream implementation evidence or a reproducible conformance/interoperability result at a named source revision.

What would upgrade a row?

Section titled “What would upgrade a row?”
  • A vendor-native row becomes Verified only when a primary vendor source names UHP directly and documents support.
  • A higher conformance claim needs a reproducible complete result for that class at a named suite/source revision.
  • A cross-server client claim should demonstrate the same client against multiple independently maintained UHP servers without relying on HarnessRouter-private behavior.

Primary sources

Section titled “Primary sources”