Initial state of openapi-request-validation library

Author: maxdev1

.gitignore

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+dist
+node_modules
+.idea

LICENSE.md

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+MIT License
+
+Copyright 2026 Max Schlüssel
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

README.md

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+# openapi-request-validation
+
+Build-time OpenAPI request validation for serverless and lightweight Node runtimes. Performs request validation based on
+OpenAPI specifications. Supports AWS Lambda API Gateway events, lambda-api requests and Express.
+
+Uses AJV to generate standalone request validators and ships runtime helpers for easy validation.
+
+## Install
+
+Install the package as a normal dependency, since it is required both at build time and runtime:
+```bash
+npm install openapi-request-validation
+```
+
+## CLI
+
+Generate validators from a spec into a target directory:
+
+```bash
+openapi-request-validation ./openapi.yaml ./src/generated
+```
+
+This writes a file such as `./src/generated/openapi-validators.js`. Each operation with a request shape gets an export
+like `validateCreateUserRequest`. Your tsconfig must specify `allowJs: true` to use these validators.
+
+## Runtime use
+
+### API Gateway
+
+Use `validateApiGatewayEvent(...)` to validate a raw API Gateway event before your handler logic runs.
+
+```ts
+import {validateCreateCustomerOrderRequest} from "./generated/openapi-validators.js"
+import {validateApiGatewayEvent} from "openapi-request-validation"
+
+export async function handler(event: unknown) {
+  validateApiGatewayEvent(validateCreateCustomerOrderRequest, event)
+
+  return {
+    statusCode: 204,
+  }
+}
+```
+
+### lambda-api
+
+Wrap route handlers with `withValidation(...)` or call `validateLambdaApiRequest(...)` directly.
+
+```ts
+import {validateCreateCustomerOrderRequest} from "./generated/openapi-validators.js"
+import {withValidation} from "openapi-request-validation"
+
+api.post(
+  "/customers/:customerId/orders",
+  withValidation(validateCreateCustomerOrderRequest, (req, res) => {
+    res.send({ok: true})
+  }),
+)
+```
+
+### Express
+
+Wrap Express handlers with `withExpressValidation(...)` or call `validateExpressRequest(...)` directly.
+
+```ts
+import express from "express"
+import {validateCreateCustomerOrderRequest} from "./generated/openapi-validators.js"
+import {withExpressValidation} from "openapi-request-validation"
+
+const app = express()
+app.use(express.json())
+
+app.post(
+  "/customers/:customerId/orders",
+  withExpressValidation(validateCreateCustomerOrderRequest, (req, res) => {
+    res.status(201).json({ok: true})
+  }),
+)
+```
+
+## Error handling
+
+The runtime helpers throw `RequestValidationError` with HTTP status `400`.
+
+If your application already uses its own error type, pass `createError` in the optional runtime options:
+
+```ts
+import {validateExpressRequest} from "openapi-request-validation"
+
+validateExpressRequest(validateCreateCustomerOrderRequest, req, {
+  createError: (message) => new BadRequestProblem(message),
+})
+```

jest.config.cjs

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+module.exports = {
+  preset: "ts-jest",
+  testEnvironment: "node",
+  testMatch: ["<rootDir>/test/**/*.test.ts"],
+  clearMocks: true,
+  moduleNameMapper: {
+    "^(\\.{1,2}/.*)\\.js$": "$1",
+  },
+  transform: {
+    "^.+\\.ts$": [
+      "ts-jest",
+      {
+        tsconfig: "<rootDir>/tsconfig.test.json",
+      },
+    ],
+  },
+}

package.json

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+{
+  "name": "openapi-request-validation",
+  "version": "0.1.0",
+  "description": "Build-time OpenAPI request validation for serverless and lightweight Node runtimes",
+  "type": "module",
+  "sideEffects": false,
+  "main": "./dist/cjs/index.js",
+  "module": "./dist/esm/index.js",
+  "types": "./dist/types/index.d.ts",
+  "bin": {
+    "openapi-request-validation": "./dist/cjs/cli.js"
+  },
+  "exports": {
+    ".": {
+      "types": "./dist/types/index.d.ts",
+      "import": "./dist/esm/index.js",
+      "require": "./dist/cjs/index.js"
+    },
+    "./generator": {
+      "types": "./dist/types/generator.d.ts",
+      "import": "./dist/esm/generator.js",
+      "require": "./dist/cjs/generator.js"
+    },
+    "./runtime": {
+      "types": "./dist/types/runtime.d.ts",
+      "import": "./dist/esm/runtime.js",
+      "require": "./dist/cjs/runtime.js"
+    },
+    "./package.json": "./package.json"
+  },
+  "typesVersions": {
+    "*": {
+      "generator": [
+        "dist/types/generator.d.ts"
+      ],
+      "runtime": [
+        "dist/types/runtime.d.ts"
+      ]
+    }
+  },
+  "files": [
+    "dist",
+    "README.md"
+  ],
+  "scripts": {
+    "build": "node ./scripts/build.mjs",
+    "test": "npm run build && node ./node_modules/jest/bin/jest.js --runInBand"
+  },
+  "keywords": [
+    "openapi",
+    "ajv",
+    "lambda",
+    "apigateway",
+    "validation"
+  ],
+  "engines": {
+    "node": ">=20"
+  },
+  "dependencies": {
+    "@apidevtools/swagger-parser": "^12.0.0",
+    "ajv": "^8.17.1",
+    "ajv-formats": "^3.0.1",
+    "openapi-types": "^12.1.3"
+  },
+  "devDependencies": {
+    "@types/express": "^5.0.3",
+    "@types/jest": "^29.5.14",
+    "@types/node": "^24.0.0",
+    "express": "^5.1.0",
+    "jest": "^29.7.0",
+    "ts-jest": "^29.4.1",
+    "typescript": "^5.8.2"
+  }
+}

playground/index.html

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+<!doctype html>
+<html lang="en">
+<head>
+  <meta charset="UTF-8" />
+  <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+  <title>OpenAPI Request Validation Playground</title>
+</head>
+<body>
+<div id="root"></div>
+<script type="module" src="/src/main.tsx"></script>
+</body>
+</html>