Stability baseline and downstream pin ledger

stability-baseline-2026-08-26.json is a dated, machine-readable evidence snapshot. It records exact Open Control Engine refs and topology, package/toolchain facts, tag versus GitHub Release state, issue and pull-request inventories, repository-policy unknowns, Studio product/program identities, and downstream OCE pin states.

This is evidence, not authority. Live repository source and repository policy remain authoritative. Moving branch heads do not invalidate this historical capture, and a later capture must be added as a new dated artifact with an explicit supersession note; this file must never be silently rewritten as though its old observations were current.

Identity boundaries

The Studio entries deliberately keep three identities separate:

1. open-control-studio product source is the reviewed behavior.
2. The selected program locator is the immutable program revision named by that product source.
3. The program repository head is newer planning work and does not define product behavior until a reviewed product locator change selects it.

Likewise, the Library’s declared ENGINE_PIN remains its exact commit even though that commit’s OCE tree equals the captured OCE development tree. Tree equivalence never substitutes for commit identity. Sim and cxf-json use none_at_revision, which is intentionally different from UNKNOWN.

Provenance and supersession

Primary Git source is named in each artifact entry by repository, exact revision, and path. The OCE package claims come from Cargo.toml, rust-toolchain.toml, and crates/oce-api/Cargo.toml at the captured development commit. Studio pins come from Cargo.toml and its selected locator from docs/roadmap/README.md at the captured product commit. Library uses ENGINE_PIN; Sim uses its Cargo manifests and ocs-bridge source; cxf-json uses all Cargo manifests. Dated GitHub observations name the API endpoint used for compare, tag, release, issue, and pull-request evidence.

The local-only 2026-08-25 planning input at _spec/open-control-engine-2026-08-25/CURRENT-BASELINE.md is absent from clean checkouts. Its relevant stale statements are quoted in the JSON rather than treated as authority: Studio product main was c756d320aa495ddd66630f0987202c6d852f27f5, its locator was 5bc001ff9dbf980e5fb7f106e2d5eb9329e842c3, and the program head was 5dd50c97472020142503ec8fdb79823fc0e56c78. The 2026-08-26 capture records the refreshed values without modifying that historical input.

Branch protection and ruleset state is UNKNOWN: the available API evidence was authorization-limited, so no absence of protection is inferred. One concrete closure step remains: a repository administrator must inspect Settings → Rules → Rulesets and Settings → Branches and record every active rule applying to development and main. Issue program owners are also UNKNOWN; empty assignee lists do not permit inferring an owner from an issue author.

Deterministic verification

This verification tool requires Python 3.11 or newer for the standard-library tomllib module. That prerequisite applies only to this documentation/evidence tool; Open Control Engine runtime and library consumers do not require Python.

The standard-library-only tool performs no network access and never compares captured refs with today’s moving branch heads:

python3 tools/stability_baseline/baseline.py --check
python3 tools/stability_baseline/baseline.py --check --source open-control-engine=.

--check rejects duplicate/extra fields, malformed or shortened SHAs, noncanonical serialization, changed exact facts, pin/tree mismatches, conflated Studio identities, missing issue/PR distinctions, and no-pin/unknown substitution. The source option additionally verifies exact local Git objects, trees, divergence, and source files by commit. It does not fetch, so source access is explicit and historical verification cannot accidentally depend on mutable heads.

Downstream exact source can be checked from explicit local clones, individually or together:

python3 tools/stability_baseline/baseline.py --check \
  --source open-control-studio=PATH \
  --source open-control-studio-program=PATH \
  --source open-control-library=PATH \
  --source open-control-sim=PATH \
  --source cxf-json=PATH

Regeneration is deterministic and review-only:

python3 tools/stability_baseline/baseline.py --write
python3 -m unittest discover -s tools/stability_baseline -p 'test_*.py' -v

Regenerate only when reviewing this dated artifact itself. A new observation date belongs in a new artifact rather than rewriting historical evidence.