OpenAPI Validation Starter Kit for JavaScript

An application template for validating requests against an OpenAPI 3.x definition, in JavaScript, for Fastly Compute.

OpenAPI, briefly

The OpenAPI Specification (OAS – originally based on the Swagger Specification) defines a standard, language-agnostic interface to RESTful APIs which allows both humans and computers to discover and understand the capabilities of the service without access to source code, additional documentation, or inspection of network traffic.

An OpenAPI definition is a document (or set of documents) that defines or describes an API.

How this starter kit helps

This starter kit makes it possible to define custom request handling logic at the edge, based on whether a request matches an OpenAPI definitions. This means:

✅ Relieving load on origins

✅ Improved API security

Running the application

To create an application using this starter kit, create a new directory for your application and switch to it, and then type the following command:

npm create @fastly/compute@latest -- --language=javascript --starter-kit=openapi-validation

Replace the contents of src/definition.json with your own OpenAPI 3.x definition, and change any references to httpbin.org to your origin in fastly.toml – by replacing the url in local_server.backends.origin, and the address (hostname) in setup.backends.origin.

To build and run your new application in the local development environment, type the following command:

npm run start

To build and deploy your application to your Fastly account, type the following command. The first time you deploy the application, you will be prompted to create a new service in your account.

npm run deploy

Request handling

The default application behavior is to only forward valid requests to the origin, and return a synthetic HTTP 400 response for invalid requests.

OpenAPI validation errors are logged in both cases.

To forward all requests to the origin, set the constant REJECT_INVALID_REQUESTS to false.

For more details about other starter kits for Compute, see the Fastly Developer Hub

Security issues

Please see our SECURITY.md for guidance on reporting security-related issues.