HN Showcase
Back to browse
GitHub Repository

JSON/YAML Type Checker

15 starsTypeScript

JTC – JSON/YAML Type Checker Using TypeScript

by disjukr·Mar 10, 2026·2 points·0 comments
Visit ProjectView on HN

AI Analysis

●MidShip It

Yet another JSON validator, but uses TypeScript types instead of JSON Schema.

Strengths
  • •TypeScript types as schema source means single source of truth for validation
  • •VSCode extension provides inline diagnostics and Go To Definition navigation
  • •CLI enables CI/CD pipeline integration with check and lsp commands
Weaknesses
  • •JSON Schema is established standard with broader ecosystem and tool support
  • •Early stage project with only 11 stars and planned features not yet implemented
Target Audience

TypeScript developers working with JSON/YAML configuration files

Similar To

JSON Schema · AJV · zod

Post Description

If you add a $schema field to JSON or YAML, you can run JSON Schema validation. Likewise, if you add a $type field, this tool performs TypeScript-based checks.

It provides both a VSCode extension and a CLI.

The VSCode extension offers Diagnostics (it draws a red underline when something is wrong) and a Go To Definition feature. Since it’s published on both the Marketplace and open-vsx, the extension can also be used in other VSCode-based editors such as Cursor.

The CLI provides check and lsp commands. With the check command, you can run JSON type checks in CI/CD, and with the lsp command, it can be integrated and used in editors other than VSCode.

I’m planning to soon implement type-based field auto-completion and a feature that shows documentation on mouse hover. I’m also considering adding type checking using other static type languages besides TypeScript.

Similar Projects