typia

Typia is a TypeScript transformer library that provides super-fast runtime validators, safe JSON parsing/stringifying, and JSON schema generation. It uses AOT (Ahead of Time) compilation to achieve high performance.

Key features include:

• Super-fast Runtime Validators: Validates data against TypeScript types at runtime.
• Strict Validators: Performs deep equality checks.
• JSON Utilities: Safe parsing and fast stringification.
• JSON Schema: Generates schemas directly from TypeScript types.

All Typia functions are designed to be used with a single line of code, requiring no manual JSON schema definitions or decorators.

// RUNTIME VALIDATORS
export function is<T>(input: unknown | T): input is T; // returns boolean
export function assert<T>(input: unknown | T): T; // throws TypeGuardError
export function validate<T>(input: unknown | T): IValidation<T>; // detailed

// STRICT VALIDATORS
export function equals<T>(input: unknown | T): input is T;
export function assertEquals<T>(input: unknown | T): T;
export function validateEquals<T>(input: unknown | T): IValidation<T>;

// JSON
export function application<T>(): IJsonApplication; // JSON schema
export function assertParse<T>(input: string): T; // type safe parser
export function assertStringify<T>(input: T): string; // safe and faster

typia is a TypeScript compiler transformer. It hooks into tsc (the TypeScript compiler) to transform TypeScript types into specialized runtime code at compile time. This generated code can be used for:

• Runtime Validation: Creating high-performance validators (e.g., typia.createIs<T>()).
• JSON Serialization: Specialized serializers/deserializers.
• LLM Schemas: Generating schemas for Large Language Models.
• Random Generators: Generating random data based on types.

Because it is a transformer, it relies on the TypeScript compiler's AST (Abstract Syntax Tree) during the build process.

// Input
typia.createIs<IPoint3d>();

// What ends up in your dist/
const _io0 = (input) =>
  "number" === typeof input.x &&
  "number" === typeof input.y &&
  "number" === typeof input.z;
const check = (input) =>
  "object" === typeof input && null !== input && _io0(input);

AutoBe is an AI agent that generates production-grade backends (requirements, database schemas, API specs, tests, and implementation) from natural language. It uses a 5-phase waterfall pipeline where the LLM fills predefined JSON Schema structures instead of writing free-form code. These structures are then validated and transformed by specialized compilers.

The 5-Phase Pipeline:

1. Analyze: Generates structured SRS using AutoBeAnalyze.
2. Database: Generates DB schema AST using AutoBeDatabase.
3. Interface: Generates OpenAPI v3.2 specs using AutoBeOpenApi.
4. Test: Generates E2E test code using AutoBeTest (supporting 30+ expression types).
5. Realize: Generates implementation code via modularized collectors and transformers.

Key Concept: The LLM fills structures; compilers write code. This approach uses schema specs as unambiguous, model-independent prompts.

Typia provides benchmark results comparing its performance against other libraries like typebox, ajv, io-ts, zod, and class-validator. Benchmarks are categorized by operation type:

• Type Checking: is (boolean check), assert (throws on failure), and validate (returns result object).
• Error Handling: assert-error and validate-error (performance when handling invalid data).
• Optimization: optimizer performance.
• Serialization: stringify (JSON serialization).
• Server Integration: server-assert, server-stringify, and server-performance (comparing fastify-typia and express-typia against pure implementations and class-transformer).

Note on Data Integrity: Results for optimizer, AJV validate, and express server-performance in this specific benchmark set were produced before workload-integrity fixes in #2049 and should be treated as historical artifacts rather than current performance indicators.