wtf is definitelytyped?

jkleinsc/definitelytyped — explained in plain English

Analysis updated 2026-07-18 · repo last pushed 2018-01-25

TypeScriptAudience · developerComplexity · 1/5DormantSetup · easy

Mindmap

mindmap
  root((repo))
    What it does
      Adds TypeScript types
      Covers JS libraries
      Enables autocomplete
    Tech stack
      TypeScript
      NPM at types
    Use cases
      Type check JS libraries
      Get editor autocomplete
      Catch bugs before running
    Audience
      TypeScript developers
    Setup
      npm install at types package
      TypeScript picks it up
      No config needed

mindmap root((repo)) What it does Adds TypeScript types Covers JS libraries Enables autocomplete Tech stack TypeScript NPM at types Use cases Type check JS libraries Get editor autocomplete Catch bugs before running Audience TypeScript developers Setup npm install at types package TypeScript picks it up No config needed

Why would anyone build with this?

REASON 1

Install @types packages to get TypeScript autocomplete for a JavaScript library.

REASON 2

Catch type errors in your editor before running code that uses an untyped library.

REASON 3

Contribute a new type definition for a library you use that lacks TypeScript support.

What's in the stack?

TypeScriptnpm

How it stacks up

	jkleinsc/definitelytyped	0xradioac7iv/tempfs	7vignesh/pgpulse
Stars	—	0	0
Language	TypeScript	TypeScript	TypeScript
Last pushed	2018-01-25	—	—
Maintenance	Dormant	—	—
Setup difficulty	easy	moderate	moderate
Complexity	1/5	3/5	4/5
Audience	developer	developer	developer

Figures from each repo's GitHub metadata at analysis time.

How do you spin it up?

Difficulty · easy Time to first run · 5min

Definitions can be removed if a library later ships its own built-in types.

Yoink these prompts

Prompt 1

Show me how to install @types definitions for a JavaScript library I'm using.

Prompt 2

Help me write and submit a type definition to DefinitelyTyped for a library.

Prompt 3

Explain why some JavaScript libraries need separate @types packages instead of built-in types.

Frequently asked questions