@oh-my-pi/omptype

@oh-my-pi/omptype

Fast, ArkType-compatible schema validation for JavaScript and TypeScript. Schemas start with a small interpreter and lazily compile after repeated use, keeping construction cheap without giving up hot-path validation speed.

Installation

npm install @oh-my-pi/omptype
# or
bun add @oh-my-pi/omptype

Runs on Node 20+ (published as compiled ESM with bundled type declarations) and Bun 1.3.14+ (which resolves the TypeScript source directly via the bun export condition). No runtime dependencies.

Usage

import { type } from "@oh-my-pi/omptype";

const Config = type({
  name: "string",
  "retries?": "number.integer >= 0",
  enabled: "boolean = true",
});

const config = Config.assert({ name: "worker" });
// { name: "worker", enabled: true }

const result = Config({ name: 42 });
if (result instanceof type.errors) {
  console.error(result.summary);
}

Schemas are callable and expose composition (.or(), .and(), .array(), .pipe(), .narrow()), object transforms (.pick(), .omit(), .partial(), .required(), .merge(), .map()), refinements, semantic comparison, error configuration, and JSON Schema emission.

Built-in keyword modules include type.string.email, type.string.uuid.v4, type.string.date.iso.parse, type.string.normalize.NFKC, type.number.integer, and the parsers under type.parse.

Named and recursive schemas

const models = type
  .scope({
    User: { name: "string", "manager?": "User" },
    Users: "User[]",
    PublicUser: "Pick<User, 'name'>",
  })
  .export();

models.User.assert({ name: "Ada", manager: { name: "Grace" } });

Scopes resolve aliases lazily, including cycles. type.module() exports a scope directly, type.define() preserves literal definitions, and type.generic("<value>", definition) builds parameterized runtime schemas.

Failed validation returns OmpErrors; each entry exposes code, path, expected, actual, problem, and message, while the aggregate exposes summary and byPath. .configure() accepts string or callback overrides for error text. .toJsonSchema() accepts target, dialect, and fallback options.

Compatibility adapters

TypeBox-style and Zod-style builders produce native omptype schemas:

import { Type, type Static } from "@oh-my-pi/omptype/typebox";
import { z } from "@oh-my-pi/omptype/zod";

const TypeBoxUser = Type.Object({ name: Type.String() });
type TypeBoxUser = Static<typeof TypeBoxUser>;

const ZodUser = z.object({ name: z.string() });
const user = ZodUser.parse({ name: "Ada" });

@oh-my-pi/omptype/ark provides the repository's ArkType compatibility facade and re-exports the same type and scope implementations.

Performance

Run the benchmark from the repository root:

bun packages/omptype/bench/bench.ts

The harness first requires every candidate to accept, reject, and transform the same fixtures correctly. Compile and cold-start results use 400 unique object schemas and report the fastest of five repetitions. Hot validation mixes valid and invalid inputs after 2,000 warmup calls. The valid-only row uses each library's public boolean path after 20,000 warmup calls.

Representative result on an Apple M4 Max with Darwin 25.6.0 and Bun 1.3.14:

Phase	omptype	ArkType	TypeBox
Compile type()	509ns	271.08µs (532.3×)	27.36µs (53.7×)
Compile + 2 validations	2.18µs	526.46µs (241.5×)	46.90µs (21.5×)

Hot workload	omptype	ArkType	TypeBox
flat-small	25ns	5.10µs (203.7×)	1.23µs (49.2×)
enum-union	27ns	4.92µs (185.0×)	2.20µs (83.0×)
nested-arrays	29ns	4.80µs (163.0×)	3.01µs (102.2×)
strict-defaults	40ns	4.85µs (122.1×)	4.92µs (123.9×)
delete-extras	22ns	4.12µs (191.6×)	2.07µs (96.0×)
record-mixed	43ns	4.32µs (100.4×)	3.35µs (77.9×)
deep-message	31ns	6.32µs (202.5×)	5.13µs (164.5×)
nested-arrays valid-only	15ns	28ns (1.8×)	45ns (2.9×)

Lower times are better. Parenthetical values show how many times slower each candidate was than omptype in this run. Results vary with hardware, runtime, thermal state, and dependency versions; use the command above for local measurements.

License

MIT