The fastest schema with next-gen DX.

Highlights:

• Works with plain JavaScript, TypeScript, and ReScript. You don't need to use any compiler.
• The fastest parsing and validation library in the entire JavaScript ecosystem (benchmark)
• Small JS footprint & tree-shakable API (Comparison with Zod and Valibot)
• Implements the Standard Schema spec
• Built-in JSON Schema support
• Detailed and easy to understand error messages
• Declarative transformations with automatic serialization support
• Immutable API with 100+ different operations
• Flexible global config
• Opt-in ReScript codegen from type definitions (ppx)

Also, you can use Sury as a building block for your own tools or use existing ones:

• tRPC, TanStack Form, TanStack Router, Hono and 19+ more using Standard Schema spec
• Anything that supports JSON Schema with S.toJSONSchema
• rescript-rest - RPC-like client, contract, and server implementation for a pure REST API
• rescript-envsafe - Makes sure you don't accidentally deploy apps with missing or invalid environment variables
• rescript-stripe - Describe and manage Stripe billing in a declarative way with code
• Internal form library at Carla

• For JS/TS users
• For ReScript users
• For PPX users

⚠️ Be aware that Sury uses new Function for parsing. The approach is battle tested and has no known security issues. It's also used by TypeBox, Zod@4 and ArkType. Although, some environments like Cloudflare Workers will not allow it.

• Welcome Sury - The fastest schema with next-gen DX (Dev.to)
• ReScript Schema unique features (Dev.to)
• Building and consuming REST API in ReScript with rescript-rest and Fastify (YouTube)

Instead of relying on a few large functions with many methods, Sury follows Valibot's approach, where API design and source code is based on many small and independent functions, each with just a single task. This modular design has several advantages.

For example, this allows a bundler to use the import statements to remove code that is not needed. This way, only the code that is actually used gets into your production build. This can reduce the bundle size by up to 2 times compared to Zod.

Besides the individual bundle size, the overall size of the library is also significantly smaller.

At the same time Sury is the fastest composable validation library in the entire JavaScript ecosystem. This is achieved because of the JIT approach when an ultra optimized validator is created using new Function.