# Docs Module Index
Entity Model Document for `api_claude` documentation collections.
### Scope
- **Purpose**: Define the entity model, mutability schema, and instance-naming conventions for the `docs/` documentation collection.
- **Responsibility**: Maintained by crate maintainers; updated whenever a new entity type is added to or removed from `docs/`.
- **In Scope**: All entity directories directly under `docs/` — their type, mutability, allowed operations, and ordering.
- **Out of Scope**: Entity types in other crates; workspace-level documentation structure; test surface entities in `tests/docs/`.
### Entity Tree
```
Entity Type Mut? Instances Purpose
──────────────────────────────────────────────────────────────────────────────
api/ Collection ✓ 1 API contracts and endpoint coverage
feature/ Collection ✓ 1 Optional enterprise feature specifications
invariant/ Collection ✓ 2 Non-negotiable behavioral constraints
operation/ Collection ✓ 1 Operational procedures for client users
pattern/ Collection ✓ 1 Reusable design patterns for contributors
```
### Entities
| `api/` | Collection | ✓ | Create, Read, Archive | 1 | No |
| `feature/` | Collection | ✓ | Create, Read, Archive | 1 | No |
| `invariant/` | Collection | ✓ | Create, Read, Archive | 1 | No |
| `operation/` | Collection | ✓ | Create, Read, Archive | 1 | No |
| `pattern/` | Collection | ✓ | Create, Read, Archive | 1 | No |
### Instance Naming
All entities use independent sequential NNN format (3-digit zero-padded, e.g. `001_`, `002_`). IDs are permanent once assigned — never reuse after deletion.