# Specifications

Formal Kaptan specifications should normally live next to the code item they govern.

Examples:

- `kaptan-runtime/src/control_loop.rs`
- `kaptan-runtime/src/control_loop.v0.1.0.spec.md`
- `kaptan-runtime/src/scheduler.rs`
- `kaptan-runtime/src/scheduler.v0.1.0.spec.md`

## Compile-Time Linking

Code implementations should link to their governing spec through `#[spec("...")]`.

Example:

```rust
use kaptan_spec::spec;

#[spec("control_loop.v0.1.0.spec.md")]
pub struct ControlLoop;
```

The attribute expands to a compile-time file inclusion guard. If the linked file does not exist, compilation fails.

## Spec Format

Formal specs are expected to declare these keys in YAML frontmatter:

- `title`
- `status`
- `owners`

Allowed statuses are:

- `in-progress`
- `implemented`
- `deprecated`

Owner entries must use full name and email address in this format:

```text
- Full Name <name@example.com>
```

The spec path is the identifier for linkage and traceability.

- The code path plus the `#[spec("...")]` reference identifies the governing spec.
- The version is part of the spec filename and therefore part of the spec identity.

## Template

Use this starter when creating a new colocated spec:

```markdown
---
title: Replace with title
status: in-progress
owners:
  - Full Name <name@example.com>
---

# TODO
```