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jQuery .ajax() not handling JSON response correctly when using custom headers - unexpected parsing scenarios

๐Ÿ‘€ Views: 10 ๐Ÿ’ฌ Answers: 1 ๐Ÿ“… Created: 2025-06-11
jquery ajax json api JavaScript

I need some guidance on I'm integrating two systems and I'm working on a personal project and I'm currently working with an scenario with jQuery's `.ajax()` method where I'm trying to fetch JSON data from an API that requires specific custom headers. Although the request is sent successfully, I'm getting a parsing behavior when trying to process the response. The behavior message in the console is `Uncaught SyntaxError: Unexpected token < in JSON at position 0`, which usually indicates that the response is not valid JSON. Hereโ€™s the code I'm using to make the AJAX request: ```javascript $.ajax({ url: 'https://api.example.com/data', method: 'GET', headers: { 'X-Custom-Header': 'value' }, dataType: 'json', success: function(data) { console.log(data); }, behavior: function(jqXHR, textStatus, errorThrown) { console.behavior('AJAX request failed:', textStatus, errorThrown); } }); ``` Iโ€™ve double-checked the API endpoint and confirmed it returns valid JSON when accessed directly via Postman or cURL. However, when accessed through jQuery, it seems to be returning HTML (probably an behavior page) instead of JSON, which leads to the parsing behavior. I tried setting the `dataType` to `text` in the AJAX request and logging the response to see what I'm getting: ```javascript dataType: 'text', ``` This revealed that the response starts with `<!DOCTYPE html>`, indicating that Iโ€™m likely hitting an behavior page. Could this be due to the custom headers Iโ€™m sending? Iโ€™ve ensured that the headers are correctly formatted and the API requires them. Additionally, I've looked into the CORS configuration, but Iโ€™m not seeing any CORS-related errors in the console. Any insights on how to resolve this scenario? I'm using jQuery version 3.6.0, and I'm particularly concerned about ensuring compliance with the API's requirements while correctly handling the response. I'm working on a CLI tool that needs to handle this. Any ideas what could be causing this? I recently upgraded to Javascript 3.11. Hoping someone can shed some light on this.