header property is required but headers property is used for sending headers

[Weeb6279]

Environment

---

• Operating System: Windows_NT
• Node Version: v22.11.0
• Nuxt Version: 3.14.159
• CLI Version: 3.15.0
• Nitro Version: 2.10.4
• Package Manager: npm@10.9.0
• Builder: -
• User Config: default
• Runtime Modules: nuxt-open-fetch@0.9.5
• Build Modules: -

---

Reproduction

Client usage

useApiClient('/api/endpoint', {
  method: 'GET',
  header: { 'X-Header': 'value' },
  mode: 'cors',
  credentials: 'same-origin',
  server: false
})

Open API schema:

{
    "x-generator": "NSwag v14.0.7.0 (NJsonSchema v11.0.0.0 (Newtonsoft.Json v13.0.0.0))",
    "openapi": "3.0.0",
    "info": {
        "title": "Api",
        "version": "1.0.0"
    },
    "servers": [
        {
            "url": "https://localhost:5071"
        }
    ],
    "paths": {
        "/api/endpoint": {
            "get": {
                "tags": [
                    "Endpoint"
                ],
                "operationId": "Endpoint_Operation",
                "parameters": [
                    {
                        "name": "X-Header",
                        "x-originalName": "xheader",
                        "in": "header",
                        "required": true,
                        "description": "Header",
                        "schema": {
                            "type": "string"
                        }
                    }
                ],
            }
        }
    }
}

Describe the bug

When generating the api client from an OpenAPI schema the header property is generated with the required headers. However when specifying the header option on the fetch function the header will not be send.
The correct property is headers. Specifying this property will send the header with fetch.

Generated Code:

    Endpoint_Operation: {
        parameters: {
            query?: never;
            header: {
                /** @description Header */
                "X-Header": string;
            };
            path?: never;
            cookie?: never;
        };
    };

Expected Code:

    Endpoint_Operation: {
        parameters: {
            query?: never;
            headers: {
                /** @description Header */
                "X-Header": string;
            };
            path?: never;
            cookie?: never;
        };
    };

Additional context

No response

Logs

No response

[emavitta]

i'm getting the same exact problem. Header is typed but it works only if the key is headers thus triggering typescript errors

[zlotnika]

I'm getting the same issue. It looks like everything is working as expected, so I'd be surprised if anyone doesn't have it. https://swagger.io/docs/specification/v3_0/describing-parameters/#header-parameters. Can we merge that PR?