Instant API – Build type-safe web APIs with JavaScript

In plain words

Instant API is a JavaScript framework for building web APIs with automatic type safety at the HTTP interface. It uses a function-as-a-service approach with modified JSDoc comments to enforce parameter validation and schema checking before requests reach endpoint code. The framework automatically generates OpenAPI specifications and handles user input sanitization, eliminating the need for separate schema validation libraries. It is designed for JavaScript developers building web APIs who want to maintain type contracts between endpoints and clients without manual validation work.

written from the facts on this page · September 2026

From the sources

Instant API: Build type-safe web APIs with JavaScript - instant-dev/api

In the maker’s words, at launch

Hey there HN! I just wrapped up an all-day documentation spree for Instant API, a JavaScript framework for easily building web APIs that implements type safety at the HTTP interface. It uses a function-as-a-service approach combined with a slightly modified JSDoc spec to automatically enforce parameter and schema…

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