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API Request Validation with JSON Schema

Zuplo is an API gateway that helps any business offer a Stripe-quality experience to developers. You can quickly set up a gateway for your any API, and add validation and documentation in minutes using JSON Schema.

Before we start, create a new project in

1/ Create a route


You can also import an OpenAPI specification to setup your gateway and routes.json quickly. This feature is in private beta - e-mail us at [email protected] to request access.

Your project will open on the Route Designer which helps you edit the routes.json file. Let's add a route with the following properties:

  • Method: POST
  • Path: /products
  • URL Rewrite:

This route will create a proxy where the gateway will forward traffic to our demo API at

2/ Add a JSON Schema

Go to and sign in (or continue as guest) and paste the following example JSON (a product) in the left window:

"name" : "Intelligent Metal Salad",
"description" : "A slim & simple Metal Gaming Keyboard",
"material" : "Metal",
"price" : 894.26

Click submit button to generate your JSON Schema specification in the right window. Click the copy button at the top right to copy the generated JSON Schema specification.

Now, in the Zuplo portal make sure you're on the Files tab and click the [+] button next to the schemas folder. Choose New Empty Schema and enter the file name product.json. Paste your JSON Schema definition into the empty file and save your changes.

3/ Add JSON Schema validation to specify a request body

Zuplo can automatically validate the body of incoming requests using your new JSON Schema. To add this to your route, open routes.json again and expand the Policies section of your route. Click Add Policy to the request pipeline. Choose the JSON Body Validation schema and change the policy configuration as follows (note that it specifies your new file):

"export": "ValidateJsonSchemaInbound",
"module": "$import(@zuplo/runtime)",
"options": {
"validator": "$import(./schemas/product.json)"

Save your changes - your API is now live with validation. Test it out using the API Test Console tab. Also, check out your developer portal by clicking the Open your Developer Portal link at the top left of the screen. Note that the documentation contains information about the request body (and you can add much more metadata in the routes.json file too to enhance your docs).

Congratulations - you validated requests with JSON Schema

Related Docs

Next Steps