▲ 1 ▼ Checker - Zero-dependency Go input validation, in-place normalization, and JSON Schema generation.

Validating user input in Go often requires piecing together separate libraries: one for struct validation, another for string trimming and normalization, and custom code or extra tooling for JSON Schemas.

Checker provides a single, zero-dependency pipeline designed around three core pillars:

• Zero External Dependencies — The core module imports nothing beyond the Go standard library. No supply-chain bloat or dependency drift.
• Unified Normalization & Validation — Clean, transform, and validate input in one atomic pass (trim lower required email). Input is mutated in-place.
• Living JSON Schemas — Struct tags generate Draft 2020-12 JSON Schema documents for frontend contract sharing and API docs without duplicating rules.