TypeScript · free, forever
The type system is the best prompt you will ever write.
Free TypeScript tutorials, plus how to use the type system as a correctness harness for AI-generated code.
Three tracks
Most tutorial sites stop at track one. Track one is the part your assistant already knows.
Track 01 · 23 lessons
Foundations
The syntax and the mental model. Short, runnable, no fluff.
Track 02 · 4 lessons
AI-Native TypeScript
Configuring agents, harnesses and feedback loops for this language. Updated as the tooling moves.
Track 03 · 4 lessons
Review & Verify
How generated code fails in this language, and the checks that catch it before your users do.
Start here
The pages people actually come back to.
AI-Native
The type system is the best prompt you will ever write
A type is a specification the compiler enforces on every edit, for free, forever. That makes TypeScript unusually well suited to a workflow where a machine writes most of the code.
AI-Native
Writing an AGENTS.md for TypeScript
Half of what people put in a TypeScript instructions file belongs in tsconfig.json instead, where it is enforced rather than suggested.
AI-Native
Type-safe LLM applications in TypeScript
A model returns a string. Your application needs a value. Everything interesting about building LLM apps in TypeScript happens at that boundary — and it is the one place `as` will hurt you most.
Foundations
Short, runnable, and honest about what you can safely skim.
Hello, World!
Your first TypeScript file, and the two commands that check it and run it.
Variables and Types
TypeScript is JavaScript plus a type checker. This is where the types start — and where you stop writing var.
Arrays
TypeScript arrays are JavaScript arrays with an element type — `string[]` rather than a bag of anything.
Manipulating Arrays
Arrays can also function as a stack. The push and pop methods insert and remove variables from the end of an array.
Operators
The arithmetic, comparison and logical operators, and the two TypeScript-relevant ones: ?? and ?.
Conditions
The if statement allows us to check if an expression is equal to true or false, and execute different code according to the result.
Get the TypeScript agent pack
A battle-tested AGENTS.md, the review checklist, and the failure-mode cheat sheet for TypeScript. One email, then occasional updates when the tooling shifts. No course pitch.
AGENTS.md now — no email needed.