Introduction
Template Literal Types are one of TypeScript's most powerful features. They let you manipulate string types at compile time, creating dynamic combinations.
Basic Syntax
They use the same syntax as JavaScript template literals but with types: type Endpoint = `/api/${'users' | 'posts'}` generates the union /api/users | /api/posts.
String Manipulators
TypeScript includes Uppercase, Lowercase, Capitalize, and Uncapitalize for transforming string types. Useful for normalizing formats.
Real Use Cases
Typing API routes with dynamic parameters, creating event types like onClick, onSubmit from a base, and generating CSS types like marginTop, marginLeft.
Advanced Inference
Combine Template Literal Types with inference to parse routes: split /api/users/123 into parts and extract dynamic parameters.
Conclusion
Template Literal Types take TypeScript typing to another level. At Vynta, we use them to create type-safe APIs and catch errors at compile time.