Harness compatibility baseline
September 19, 2026 · View on GitHub
This is the first-release compatibility baseline observed on 2026-09-19. It records the installed harness versions used for the release-preparation checks; it is not a claim that every provider/model combination was exercised.
| Harness | Version observed | Release-preparation coverage |
|---|---|---|
| OMP | 18.2.6 | omp --version; OMP extension contract and host-owned execution path reviewed; Jev core smoke uses the same MCP/CLI contract. |
| Hermes | 0.21.3 (upstream b675e6de) | hermes --version; Python adapter syntax/contract reviewed; Jev core smoke uses the same CLI/MCP contract. |
| Codex CLI | 0.155.1 | codex --version; Codex MCP transport fixture and host-execution ownership path reviewed. The fixture does not invoke a Codex model. |
The adapters are thin and target the stable v1 contract documented in CONTRIBUTING.md and SCHEMA-VERSIONING.md. Full interactive harness/model/provider coverage is environment-specific and is not required for ordinary PR CI.
When a public release supports a different harness version, update this table, rerun the adapter/transport checks, and document any compatibility change in CHANGELOG.md before tagging.