# Feature Doc Entity
Behavioral requirements defining what the `unilang_parser` crate must do.
### Scope
- **Purpose:** Document functional requirements for parser behavior
- **Responsibility:** Answers: what parsing behaviors must the crate exhibit, what are the API contracts
- **In Scope:** Entry-point method signatures, input/output contracts, parser capability requirements
- **Out of Scope:** Internal parsing algorithms, tokenization implementation, architectural constraints
### Overview Table
| 001 | [Parser Public API](001_parsing_api.md) | Entry-point method signatures and semantic ignorance contract | ✅ |