An in-code, AI-native annotation system + multi-language toolchain: markers like @spec/@why/@ideal/@rule/@link live right on the code, distilled by per-language tools into a machine-readable asset for AI to consume. It is the shared source-of-truth for spec/case assets bound to code, used white-box by case-code-review (ccr) and black-box by test/eval/perf harnesses. ｜ 中文: README.zh-CN.md

A spec states the intent/contract of a code symbol. A CaseSet case is a reusable black-box stimulus plus per-face judgment criteria; spec.json carries the smaller white-box checklist projection attached to a symbol. spec-case's distinct contribution is the stable code↔spec/case binding — the symbol-id — shared by those assets. That binding supports two consumer paths:

• A harness runs black-box cases (case → verdict).
• ccr attaches the white-box projection to a changed review unit as a per-function checklist.

A review unit is the review-side twin of a case: same "requirement/contract" asset, two consumers. why, ideal, rule, and link are white-box structured intent; they compile into spec.json and do not alter the black-box CaseSet.

Think of spec-case markers as structured comments bound to code symbols — more precisely, structured intent annotations. They preserve the reasoning that cannot be recovered reliably from the implementation alone, while keeping it addressable and machine-readable:

• spec records what the code is intended to guarantee.
• why records why the symbol uses its current design, ordering, or boundary when code only reveals how.
• ideal records the shape the symbol should converge toward when current constraints no longer apply; it is not a roadmap commitment.
• rule records what a future change or review must keep in mind.
• link points to design context or a related symbol through an explicit repo:// or component:// path anchor.
• case adds a concrete validation scenario when one is worth preserving; it is optional.

Their primary purpose is not to replace unit or e2e tests. Tests and harnesses prove behavior; markers preserve the intent behind that behavior. Unlike free-form comments, markers use a stable vocabulary, bind to a symbol-id, compile into spec.json, and can be checked for drift with specgen --check.

• docs/ — concepts.md, glossary.md
• spec/ — normative schemas, the symbol-id contract, and per-language marker grammars
• conformance/ — shared behavior fixtures every language toolchain must pass
• toolchains/python/ — the pip package: markers, specgen, and the optional canonical Case model
• toolchains/go/ — Go specgen plus the importable canonical model package
• toolchains/typescript/ — TypeScript decorators, JSDoc markers, and the Compiler API specgen
• toolchains/rust/ — Rust doc-comment markers and the syn-based specgen

pip install spec-case          # markers + specgen only, zero deps
pip install 'spec-case[model]' # + canonical Case model (pydantic, pyyaml)
npm install @compforge/spec-case # TypeScript CaseSet runtime + markers + specgen
cargo run --manifest-path toolchains/rust/Cargo.toml --bin specgen -- --help # Rust specgen

Early WIP. The case model and vocabulary are standard test/eval terms; the symbol-id binding is the new piece this project owns.