diff --git a/http_stuff.c b/http_stuff.c
index ab235e1..8de6e98 100644
--- a/http_stuff.c
+++ b/http_stuff.c
@@ -117,4 +117,20 @@ char* get_header_value_request(http_request* req, char* key) {
         }
     }
     return NULL;
+}
+
+void request_add_header_n(http_request* req, char* key, size_t key_length,
+                          char* value, size_t value_length) {
+    req->num_headers++;
+    req->headers = realloc(req->headers, req->num_headers * sizeof(header_kv));
+    req->headers[req->num_headers - 1].key = malloc(key_length + 1);
+    req->headers[req->num_headers - 1].value = malloc(value_length + 1);
+    memcpy(req->headers[req->num_headers - 1].key, key, key_length);
+    memcpy(req->headers[req->num_headers - 1].value, value, value_length);
+    req->headers[req->num_headers - 1].key[key_length] = '\0';
+    req->headers[req->num_headers - 1].value[value_length] = '\0';
+}
+
+void request_add_header(http_request* req, char* key, char* value) {
+    request_add_header_n(req, key, strlen(key), value, strlen(value));
 }
\ No newline at end of file
diff --git a/http_stuff.h b/http_stuff.h
index 1d1e56f..239fbf3 100644
--- a/http_stuff.h
+++ b/http_stuff.h
@@ -2,6 +2,7 @@
 #define HTTP_STUFF_H
 
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 #include <sys/types.h>
 
@@ -141,4 +142,35 @@ char* reponse_to_string(http_response* res);
  */
 char* get_header_value_request(http_request* req, char* key);
 
+/**
+ * Adds a new header to an http_request struct with the given key and value.
+ *
+ * @param req The request to add the header to
+ * @param key The key of the header
+ * @param key_length The length of the key
+ * @param value The value of the header
+ * @param value_length The length of the value
+ *
+ * @details
+ * This function is meant to be used when the lengths of the key and value are
+ * already known. It is more efficient than request_add_header, which calls
+ * strlen to get the lengths of the key and value.
+ */
+void request_add_header_n(http_request* req, char* key, size_t key_length,
+                          char* value, size_t value_length);
+
+/**
+ * Adds a header to the given HTTP request.
+ *
+ * @param req The request to add the header to
+ * @param key The key of the header to add
+ * @param value The value of the header to add
+ *
+ * @details
+ * This is a convenience function for request_add_headern. It will add a header
+ * with the given key and value to the given request. It will automatically
+ * calculate the length of the key and value.
+ */
+void request_add_header(http_request* req, char* key, char* value);
+
 #endif
\ No newline at end of file