Opcore starts by counting the repository. TypeScript, JavaScript, Rust sources, Cargo.toml, retained Rust metadata, and Python .py/.pyi files are recognized for alpha checks. Unsupported extensions are still counted with examples so reports do not imply broader coverage than exists.
Python coverage is experimental and degraded-honest. Graph-backed structure, untested modules, dead exports, syntax, source-hygiene, import graph, and relevant-test signals may be reported for .py/.pyi files. python.types executes exactly one configured mypy or Pyright authority per project over the same hypothetical after-state. Missing, conflicting, or unavailable authority evidence is degraded instead of becoming a fake pass/fail finding.
Findings are named signals such as typescript.type_errors, rust.source_hygiene, python.syntax, python.source-hygiene, python.types, python.import-graph, python.dead-code, python.relevant-tests, and coverage.unsupported_stacks. Counts come from validation diagnostics, graph evidence when available, optional-tool degradation, and repository census data. Opcore does not blend them into a single rating.
Successful scans may write only these artifacts:
.opcore/report.json
.opcore/history.jsonl
.opcore/telemetry.jsonl
Telemetry is bounded command latency evidence capped at 500 records or 1 MiB.
Scan/status/check/measure are read-only for source files. opcore measure
reads existing report and history artifacts and reports baseline/previous
deltas. It does not run checks, build graph data, install packages, or edit
source.
opcore init is approval-gated. Without --approve, it returns a plan. With
--approve, it writes only additive .opcore/config, one delimited guidance
block in an existing agent file or new AGENTS.md, a managed .opcore/ line in
.gitignore for Git repos, and .opcore/init-undo.json.
Undo with opcore init --undo; it removes only recorded setup artifacts where
supported.
For private ASP-hosted dogfood, Opcore can run as the check provider behind a host. The host owns workspace grants, decisions, and receipts; Opcore returns provider assessments and degraded coverage when graph or tool surfaces are unavailable.