all you need to "learn" ArkType syntax: 1️⃣ start with a typescript keyword 2️⃣ .autocomplete to discover constraints 3️⃣ compose if needed with &, |, etc.

tools are just introspectable functions... what if you could define them like this?🤔

wish TS had rust-style pattern matching? (it already does)🪄

🚨Standard JSON Schema v1 just dropped🚨 🟢libraries can now accept ArkType wherever they need JSON Schema 🟢100% type-safe with inference built-in 🟢day one support from AI SDK 🟢TanStack AI and MCP SDK support imminent

🎉Announcing Standard JSON Schema🎉 The next spec in the Standard Schema family is here to bring library-agnostic JSON Schema to TS. Let's make sure everyone sees it🔁

Introducing ✨ Standard JSON Schema ✨ It's a sister spec to Standard Schema that provides a common interface for any entity that can be converted to JSON Schema

mission accomplished @mattpocock.com

the typescript ecosystem *desperately* needs type performance tooling. it's not an overstatement to say this is one of the biggest leaps in that area in the history of the language🙇

sounds fake but I'm starting a company with my nemesis Colin P. Zod and our first hire is @AndaristRake and our first product is now in beta

95% of ArkType syntax is just TypeScript. The other 5% are extensions like this that are... ✅composable ✅consistent across data types ✅100% safe with helpful type-level error messages

once you go type("string") you never go z.back()

iyky (you don't)

In the next version of ArkType, any Standard Schema is a valid definition. Zod migration is about to get a whole lot easier🚀

fastest, cleanest tuple validation around

RIP z.shark() long live sharktype

use a wrapper

agonized for a long time on syntax to return a regex's capture groups rather than just validating the input string... what do you think?

📈arkregex just hit 100k installs/week📈 if you're still using untyped RegExp() you may as well just write raw .js

string validation has never been this easy arktype🤝arkregex

problem: your RegExp is beyond human comprehension solution: pnpm i arkregex

I'll take "meticulously typed regex features you probably didn't know existed" for $500

in the latest version of arktype: regex properties and index signatures from arkregex🔒

imagine using untyped regex in 2025

arkregex is ridiculously optimized. even expressions like this are inferred instantly. but what about the most extreme cases?🧵

new RegExp(): ❌types 😴tired arkregex: ✅types 🫨wired

I am looking for a full-time job. Being independent in open source for 3.5+ years has been wonderful. I've gotten done most of the high-level goals I wanted to, and miss having people & structure around me. If you know of a role for a staff-level TypeScript+web developer, let me know! 🙂

hopefully this is not too insensitive

my abusive relationship with typescript's type system continues

📢Introducing ArkRegex📢 a drop in replacement for new RegExp() with types ⬇️

new to typescript? here's a handy little type for parsing regular expressions:

soon

🙅convoluted regex 👍simple types

days of remaining sanity also numbered btw

Ever get mixed up about unions and intersections? ArkType has your back🫡

"any sufficiently advanced typescript types are indistinguishable from magic" - Arthur C. Clark, 1962

Like type-safe environment variables? Now there's a better way to get them with arkenv⛵❤️

worth it

had an amazing time with @typescript.fm. if you're interested in a deep-dive on typescript validation and @arktype.io, this is for you! 👇

attest can snapshot types, type errors and autocomplete results. all from your existing unit tests📚🔗⬇️

⚠️trade offer⚠️ i receive: JSON Schema you receive: lightning-fast validation and clear errors

How to use ArkType: 1️⃣ write typescript 2️⃣ use it in editor 3️⃣ use it at runtime

This opens up so many doors. Counting on the community to help find them🙏

it's just too easy

zod4 is 5x faster than zod3 for object validation. arktype is 20x faster than zod4.

JSON Schema: Making illegal states representable since 2007

shoutout to @typescriptlang.org- still blown away that this works🤯

you deserve better type errors

the fields medal is a lock if you can do this

you haven't lived until you've seen autocomplete for "string | n" try it in-browser 🛝🔗👇

🌶️hover clarity is a huge part of typescript dx