TypeScript validation compiler

TypeSea

Schema in. Optimized type guard out.

Define one immutable schema, narrow unknown input safely, then choose interpreted, JIT, AOT, or boolean-only execution for each boundary.

npm install typesea

Quick start

Runtime dependencies: zero
Execution paths: plan · JIT · AOT
Module format: ESM-only
Node.js: ≥ 20.19

Quick start

Schema → guard → compiled predicate.

import { compile, t, type Infer } from "typesea";

const User = t.strictObject({
    id: t.string.uuid(),
    age: t.number.int().gte(0),
    role: t.enum(["admin", "user"])
});

type User = Infer<typeof User>;
const isUser = compile(User);

if (isUser(input)) {
    input.id;
}

Execution model

One schema, explicit execution choices.

The safe path defends hostile inputs. Trusted-data modes exchange those checks for direct property reads without changing the schema API.

01 Immutable schema

02 Validation plan

03A Interpreter

03B JIT / AOT

Safe by default

Own-property descriptor reads avoid executing getters while strict objects reject undeclared own keys.

Hot-path control

Compile once, cache explicitly, or emit AOT source. Unsafe and unchecked modes remain opt-in.

Schema analysis tools

SeaFlow derives adversarial cases; SeaBreeze joins observed values into a compact inferred schema.

Measured performance

Warm-path results, with execution modes kept separate.

The chart is generated from the checked-in benchmark result. Compare safe, unsafe, unchecked, interpreted, and ecosystem paths as different contracts.

Apple M4 Node v24.13.0 V8 13.6.233.17-node.37 median · 3 runs Jul 10, 2026

Valid object · boolean guard

Operations per second · warmed median

Valid object · boolean guard
Validator	Operations per second
TS interpreted	420592
TS safe	5103157
TS unsafe	33092344
TS unchecked	40373998
Zod	1291315
Valibot	1279777
Ajv	4219206

Valid object · diagnostics

Operations per second · warmed median

Valid object · diagnostics
Validator	Operations per second
TS interpreted	417305
TS safe	4319802
TS unsafe	27269601
TS unchecked	33987147
Zod	1282523
Valibot	1204020
Ajv	4262427

Invalid object · fast-fail

Operations per second · warmed median

Invalid object · fast-fail
Validator	Operations per second
TS interpreted	3095730
TS safe	42378094
TS unsafe	50016548
TS unchecked	50468276
Zod	82542
Valibot	928058
Ajv	29102274

Invalid object · diagnostics

Operations per second · warmed median

Invalid object · diagnostics
Validator	Operations per second
TS interpreted	35271
TS safe	1983296
TS unsafe	2830517
TS unchecked	3352127
Zod	76309
Valibot	895002
Ajv	29650288

Methodology and raw data

Existing Zod-shaped code

Try the compatibility facade without rewriting the call site.

The facade is documented as a compatibility layer, while TypeSea-native builders expose compiler and analysis features directly.

API reference

// Existing import
import { z } from "zod";

// Compatibility experiment
import { z } from "typesea/v4";

const User = z.object({
    id: z.string().uuid(),
    email: z.string().email()
}).strict();