htmx:config:request

The htmx:config:request event fires after request parameters are built but before validation and sending.

When It Fires

After htmx has constructed the request context but before htmx:confirm or htmx:before:request.

Event Detail

The event provides a ctx object with the following structure:

{
    sourceElement,  // Element that triggered the request
    sourceEvent,    // Event that triggered it
    target,         // Where the response will go
    select,         // hx-select value
    selectOOB,      // hx-select-oob value
    swap,           // hx-swap value
    push,           // hx-push-url value
    replace,        // hx-replace-url value
    transition,     // Whether to use view transitions
    request: {
        validate,     // Whether to validate the form
        action,       // Request URL
        method,       // HTTP method
        headers,      // Request headers object
        body,         // Request body (FormData)
        credentials,  // Fetch credentials mode
        mode,         // Fetch mode
        cache,        // Fetch cache mode
        timeout,      // Timeout in milliseconds
        // ... any other fetch options
    }
}

You can modify any property to change the request.

Call evt.preventDefault() to cancel the request.

Examples

Add authentication to all requests

document.body.addEventListener('htmx:config:request', function(evt) {
    evt.detail.ctx.request.headers['X-Auth-Token'] = getAuthToken();
});

Set longer timeout for specific endpoint

htmx.on('htmx:config:request', (evt) => {
    if (evt.detail.ctx.request.action.includes('/slow-endpoint')) {
        evt.detail.ctx.request.timeout = 30000;
    }
});

Include credentials for CORS requests

document.body.addEventListener('htmx:config:request', function(evt) {
    if (evt.detail.ctx.request.action.startsWith('https://api.example.com')) {
        evt.detail.ctx.request.credentials = 'include';
        evt.detail.ctx.request.mode = 'cors';
    }
});

Cancel request based on condition

htmx.on('htmx:config:request', (evt) => {
    if (!isUserAuthorized()) {
        evt.preventDefault();
    }
});

Notes

• This is the ideal place to modify request configuration globally
• Changes made here apply after hx-config attributes are processed
• Use this for cross-cutting concerns like authentication, logging, or global timeouts