Lightweight library to validate requests and responses, according to your API blueprint.

Usage no npm install needed!

<script type="module">
  import bluth from '';



A lightweight promise-based library to validate payloads against a specified JSON Schema within your API Blueprint.


It encourages developers to utilise their API blueprint as a 'source of truth', creating synergy between documentation and source code. This ultimately improves quality and developer-experience for those using the API.

For example:

  • Validate request bodies in your routing middleware
  • Validate response bodies within tests


npm install bluth --save


var Bluth = require( 'bluth' );

 * A default error schema can be provided to catch any
 * response status codes that aren't listed in the Blueprint
var bluth = new Bluth( myBlueprintMarkdown, {
  defaultErrorSchema: myDefaultErrorSchema
} );
Finding a schema
bluth.find( {

  // 'request' or 'response'
  type: 'reponse',

  // URL path
  route: '/my/route',

  // HTTP method
  method: 'GET',

  // HTTP status code (required if type is 'response')
  statusCode: 200

} )
  .then( function( schema ) {
    // hooray!
  } );
Validating a payload

Uses jsonschema's built in validation method.

bluth.validate( myRequestData, {
  type: 'request',
  route: '/my/resource/:resourceId',
  method: 'GET'
} )
  .then( function() {
    // Success!
  } )
  .catch( function( error ) {
    // Error thrown from jsonschema, with validation errors listed
  } );
Retrieving the Blueprint object
  .then( function( blueprint ) {
    // hooray!
  } );

Why the name?

A pun on 'Blueprint' and 'source of truth', with Arrested Development references. I thought it was funny at the time.