This is the official Go implementation of JSON Web Tokens (JWT), currently at v5. It provides a comprehensive library for creating, signing, parsing, and validating JWTs. The core package implements all standard JWT claims (RegisteredClaims and MapClaims), multiple signing algorithms (HMAC-SHA, RSA, RSA-PSS, ECDSA, Ed25519), and a flexible parser with functional options for configuration (e.g., allowed algorithms, leeway, audience/issuer/subject validation). The library also includes a `request` subpackage for extracting tokens from HTTP requests via headers or form/query parameters, and a `cmd/jwt` CLI tool for debugging and batch operations. Architecturally, it follows a clean separation of concerns: signing methods implement a common `SigningMethod` interface, claims implement a getter-based `Claims` interface, and validation is handled by a stand-alone `Validator` struct that can be used independently of parsing. The code is well-tested, uses only the Go standard library (no third-party dependencies), and follows modern Go idioms like functional options and error wrapping (Go 1.20+). It is actively maintained with CI, linting, CodeQL, and spell-check workflows.