Conformance is observable behavior
UHP does not define conformance as “we implement similar endpoints” or a self-declaration. The official suite sends requests to a live server and verifies required behavior, including real agent tasks.
| Class | Current checks | Main coverage |
|---|---|---|
| Core | 37 | Discovery, version negotiation, auth, errors, harness/model discovery, execution, streaming, sessions and cancellation. |
| Extended | +8 | Session inspection, file input, artifacts, download headers and traversal probes. |
| Full | +7 | Harness lifecycle, unsupported-base refusal, skill bundles, MCP and disabled-tool persistence. |
Total: 52 checks in the current repository state reviewed on 15 August 2026.
Why schema validation is not enough
Some protocol failures only appear during execution. A stream can have the correct media type and still buffer every event until the task is over. A cancellation endpoint can return success while the underlying agent keeps running. An artifact route can match its schema while allowing unsafe path traversal.
The conformance suite therefore includes live behavioral checks such as progressive stream delivery, cancellation reaching a terminal state, artifact security headers and path traversal probes.
Current reference result
The repository records HarnessRouter Community Edition 0.3.0 as passing the Full class against UHP 2026-08-11, with 52 of 52 checks passed in the documented run.
What to demand from a third-party claim
- Protocol version named explicitly.
- Conformance class stated: Core, Extended or Full.
- A reproducible run or machine-readable report.
- No skipped tests presented as passes.
- Independent verification where the claim matters commercially.