Koa 1.x Request Validation Middleware

koa-validate is a middleware designed for Koa 1.x applications to validate incoming request parameters, including body, query, URL parameters, files, and headers. It extends the Koa context with methods like `checkBody`, `checkQuery`, `checkParams`, `checkFile`, and `checkHeader`, allowing developers to define validation rules directly within route handlers. The library internally leverages the `validator.js` library for a wide range of validation methods and also supports custom error messages and data sanitization. It features specialized validation for multipart file uploads (requiring `koa-body`) and advanced JSON body validation using JSONPath expressions. The current stable version is 1.0.7, but it appears to be largely unmaintained, with no significant updates in several years. Its core functionality is built around Koa 1.x's generator-based middleware pattern, making it incompatible with modern Koa 2.x+ `async/await` applications without substantial refactoring or a legacy Koa setup.