diff --git a/frankenphp/frankenphp.php b/frankenphp/frankenphp.php
new file mode 100644
index 000000000..99ba64bbc
--- /dev/null
+++ b/frankenphp/frankenphp.php
@@ -0,0 +1,58 @@
+<?php
+
+/**
+ * Sends HTTP response headers immediately.
+ *
+ * This function can be used to send 1XX informative responses, for instance 103 "Early Hints" responses.
+ * This function can be called multiple times, allowing to send multiple informative responses before the final one.
+ *
+ * @link https://frankenphp.dev/docs/early-hints/
+ *
+ * @return int the HTTP status code of this response
+ */
+function headers_send(int $status = 200): int {}
+
+/**
+ * Handles an HTTP request with the provided callbacl.
+ *
+ * When called, superglobals, php://input and the like are reset to reflect the values of the handled request.
+ *
+ * @link https://frankenphp.dev/docs/worker/
+ *
+ * @return bool returns <b>FALSE</b> if the server is terminating, giving the opportunity to the worker script to finish cleanly
+ */
+function frankenphp_handle_request(callable $callback): bool {}
+
+/**
+ * Flushes all response data to the client and finishes the request.
+ * This allows for time-consuming tasks to be performed without leaving the connection to the client open.
+ *
+ * Alias of <b>fastcgi_finish_request</b>.
+ *
+ * @link https://www.php.net/manual/en/function.fastcgi-finish-request.php
+ *
+ * @return bool Returns <b>TRUE</b> on success or <b>FALSE</b> on failure.
+ */
+function frankenphp_finish_request(): bool {}
+
+/**
+ * Fetches all HTTP request headers from the current request.
+ *
+ * Alias of <b>apache_request_headers</b>.
+ *
+ * @link https://php.net/manual/en/function.apache-request-headers.php
+ *
+ * @return array An associative array of all the HTTP headers in the current request.
+ */
+function frankenphp_request_headers(): array {}
+
+/**
+ * Fetches all HTTP response headers.
+ *
+ * Alias of <b>apache_response_headers</b>.
+ *
+ * @link https://php.net/manual/en/function.apache-response-headers.php
+ *
+ * @return array|false An array of all FrankenPHP response headers on success or <b>FALSE</b> on failure.
+ */
+function frankenphp_response_headers(): array|bool {}