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Author image Jan Henning Thorsen
and 3 contributors


Mojolicious::Plugin::OpenAPI - OpenAPI / Swagger plugin for Mojolicious


  use Mojolicious::Lite;

  # Will be moved under "basePath", resulting in "POST /api/echo"
  post "/echo" => sub {

    # Validate input request or return an error document
    my $c = shift->openapi->valid_input or return;

    # Generate some data
    my $data = {body => $c->req->json};

    # Validate the output response and render it to the user agent
    # using a custom "openapi" handler.
    $c->render(openapi => $data);
  }, "echo";

  # Load specification and start web server
  # Use "v3" instead of "v2" for "schema" if you are using OpenAPI v3
  # The plugin must be loaded *after* defining the routes in a Lite app
  plugin OpenAPI => {url => "data:///spec.json", schema => "v2"};

  @@ spec.json
    "swagger" : "2.0",
    "info" : { "version": "0.8", "title" : "Echo Service" },
    "schemes" : [ "http" ],
    "basePath" : "/api",
    "paths" : {
      "/echo" : {
        "post" : {
          "x-mojo-name" : "echo",
          "parameters" : [
            { "in": "body", "name": "body", "schema": { "type" : "object" } }
          "responses" : {
            "200": {
              "description": "Echo response",
              "schema": { "type": "object" }

See Mojolicious::Plugin::OpenAPI::Guides::OpenAPIv2 or Mojolicious::Plugin::OpenAPI::Guides::OpenAPIv3 for tutorials on how to write a "full" app with application class and controllers.


Mojolicious::Plugin::OpenAPI is Mojolicious::Plugin that add routes and input/output validation to your Mojolicious application based on a OpenAPI (Swagger) specification. This plugin supports both version 2.0 and 3.x, though 3.x might have some missing features.

Have a look at the "SEE ALSO" for references to more documentation.

Please report in issues or open pull requests to enhance the 3.0 support.



  $hash = $c->openapi->spec($json_pointer)
  $hash = $c->openapi->spec("/info/title")
  $hash = $c->openapi->spec;

Returns the OpenAPI specification. A JSON Pointer can be used to extract a given section of the specification. The default value of $json_pointer will be relative to the current operation. Example:

    "paths": {
      "/pets": {
        "get": {
          // This datastructure is returned by default


  @errors = $c->openapi->validate;

Used to validate a request. @errors holds a list of JSON::Validator::Error objects or empty list on valid input.

Note that this helper is only for customization. You probably want "openapi.valid_input" in most cases.


  $c = $c->openapi->valid_input;

Returns the Mojolicious::Controller object if the input is valid or automatically render an error document if not and return false. See "SYNOPSIS" for example usage.


Mojolicious::Plugin::OpenAPI will emit the following hooks on the application object.


Emitted after all routes have been added by this plugin.

  $app->hook(openapi_routes_added => sub {
    my ($openapi, $routes) = @_;

    for my $route (@$routes) {

This hook is EXPERIMENTAL and subject for change.


This plugin register a new handler called openapi. The special thing about this handler is that it will validate the data before sending it back to the user agent. Examples:

  $c->render(json => {foo => 123});    # without validation
  $c->render(openapi => {foo => 123}); # with validation

This handler will also use "renderer" to format the output data. The code below shows the default "renderer" which generates JSON data:

    OpenAPI => {
      renderer => sub {
        my ($c, $data) = @_;
        return Mojo::JSON::encode_json($data);



  $route = $openapi->route;

The parent Mojolicious::Routes::Route object for all the OpenAPI endpoints.


  $jv = $openapi->validator;

Holds a JSON::Validator::OpenAPI::Mojolicious object.



  $openapi = $openapi->register($app, \%config);
  $openapi = $app->plugin(OpenAPI => \%config);

Loads the OpenAPI specification, validates it and add routes to $app. It will also set up "HELPERS" and adds a before_render hook for auto-rendering of error documents. The return value is the object instance, which allow you to access the "ATTRIBUTES" after you load the plugin.

%config can have:


The OpenAPI specification does not allow "$ref" at every level, but setting this flag to a true value will ignore the $ref check.

Note that setting this attribute is discourage.


See "coerce" in JSON::Validator for possible values that coerce can take.

Default: booleans,numbers,strings

The default value will include "defaults" in the future, once that is stable enough.


A list of response codes that will get a "$ref" pointing to "#/definitions/DefaultResponse", unless already defined in the spec. "DefaultResponse" can be altered by setting "default_response_name".

The default response code list is the following:

  400 | Bad Request           | Invalid input from client / user agent
  401 | Unauthorized          | Used by Mojolicious::Plugin::OpenAPI::Security
  404 | Not Found             | Route is not defined
  500 | Internal Server Error | Internal error or failed output validation
  501 | Not Implemented       | Route exists, but the action is not implemented

Note that more default codes might be added in the future if required by the plugin.


The name of the "definition" in the spec that will be used for "default_response_codes". The default value is "DefaultResponse". See "Default response schema" in Mojolicious::Plugin::OpenAPI::Guides::OpenAPIv2 for more details.


log_level is used when logging invalid request/response error messages.

Default: "warn".


A list of OpenAPI classes to extend the functionality. Default is: Mojolicious::Plugin::OpenAPI::Cors, Mojolicious::Plugin::OpenAPI::SpecRenderer and Mojolicious::Plugin::OpenAPI::Security.

  $app->plugin(OpenAPI => {plugins => [qw(+Cors +SpecRenderer +Security)]});

You can load your own plugins by doing:

  $app->plugin(OpenAPI => {plugins => [qw(+SpecRenderer My::Cool::OpenAPI::Plugin)]});




route can be specified in case you want to have a protected API. Example:

  $app->plugin(OpenAPI => {
    route => $app->routes->under("/api")->to("user#auth"),
    url   => $app->home->rel_file("cool.api"),


Can be used to set a different schema, than the default OpenAPI 2.0 spec. Example values: "http://swagger.io/v2/schema.json", "v2" or "v3".

See also Mojolicious::Plugin::OpenAPI::Guides::OpenAPIv2 and Mojolicious::Plugin::OpenAPI::Guides::OpenAPIv3.


Name of the route that handles the "basePath" part of the specification and serves the specification. Defaults to "x-mojo-name" in the specification at the top level.


See "schema" in JSON::Validator for the different url formats that is accepted.

spec is an alias for "url", which might make more sense if your specification is written in perl, instead of JSON or YAML.


Can be used to overridden /info/version in the API specification, from the return value from the VERSION() method in version_from_class.

This will only have an effect if "version" is "0".

Defaults to the current $app.


Henrik Andersen

Ilya Rassadin

Jan Henning Thorsen

Joel Berger


Copyright (C) Jan Henning Thorsen

This program is free software, you can redistribute it and/or modify it under the terms of the Artistic License version 2.0.