Load exportd JSON ACF fields via PHP – https://dev.to/jacobdb/import-acf-fields-via-php-without-losing-importability-5a8o/

acf-register-json-fields.php

<?php
/**
 * Read ACF fields from JSON
 */
function PREFIX_acf_register_json_fields() {
    if (function_exists("acf_add_local_field_group")) {
        $acf_json_data = locate_template("path/to/advanced-custom-fields.json");
        $custom_fields = $acf_json_data ? json_decode(file_get_contents($acf_json_data), true) : array();

        foreach ($custom_fields as $custom_field) {
            acf_add_local_field_group($custom_field);
        }
    }
}
add_action("init", "PREFIX_acf_register_json_fields");

@joshespi I just tested this, and it seems to be working correctly for me with the latest versions of WordPress and ACF Pro. The below code will add a text field called "Test" to all posts in the post post type.

Here's my PHP, in functions.php:

/**
 * Read ACF fields from JSON
 */
function PREFIX_acf_register_json_fields() {
    if (function_exists("acf_add_local_field_group")) {
        $acf_json_data = get_theme_file_path("acf-export-2023-04-12.json");
        $custom_fields = $acf_json_data ? json_decode(file_get_contents($acf_json_data), true) : array();

        foreach ($custom_fields as $custom_field) {
            acf_add_local_field_group($custom_field);
        }
    }
}
add_action("init", "PREFIX_acf_register_json_fields");

And here's my export file, in the root of the theme, named acf-export-2023-04-12.json:

[
    {
        "key": "group_6436dd39db816",
        "title": "Test",
        "fields": [
            {
                "key": "field_6436dd3ab6565",
                "label": "Test",
                "name": "test",
                "aria-label": "",
                "type": "text",
                "instructions": "",
                "required": 0,
                "conditional_logic": 0,
                "wrapper": {
                    "width": "",
                    "class": "",
                    "id": ""
                },
                "relevanssi_exclude": 0,
                "default_value": "",
                "maxlength": "",
                "placeholder": "",
                "prepend": "",
                "append": ""
            }
        ],
        "location": [
            [
                {
                    "param": "post_type",
                    "operator": "==",
                    "value": "post"
                }
            ]
        ],
        "menu_order": 0,
        "position": "normal",
        "style": "default",
        "label_placement": "top",
        "instruction_placement": "label",
        "hide_on_screen": "",
        "active": true,
        "description": "",
        "show_in_rest": 0
    }
]

thanks for the quick reply!

I figured out my issue. I was trying to put the function to load the json in a plugin rather than my functions.php file.

moving things made it work as you described. Thanks for helping me work through that!