diff --git a/tools/helper/utils.h b/tools/helper/utils.h
new file mode 100644
index 0000000..d521b80
--- /dev/null
+++ b/tools/helper/utils.h
@@ -0,0 +1,90 @@
+#pragma once
+#include "common.h"
+#include <rawrtc.h>
+#include <rawrtcc.h>
+#include <rawrtcdc.h>
+#include <re.h>
+
+/*
+ * Convert string to uint16.
+ */
+bool str_to_uint16(uint16_t* const numberp, char* const str);
+
+/*
+ * Convert string to uint64.
+ */
+bool str_to_uint64(uint64_t* const numberp, char* const str);
+
+/*
+ * Convert string to uint32.
+ */
+bool str_to_uint32(uint32_t* const numberp, char* const str);
+
+/*
+ * Get a dictionary entry and store it in `*valuep`.
+ */
+enum rawrtc_code dict_get_entry(
+    void* const valuep,
+    struct odict* const parent,
+    char* const key,
+    enum odict_type const type,
+    bool required);
+
+/*
+ * Get a uint32 entry and store it in `*valuep`.
+ */
+enum rawrtc_code dict_get_uint32(
+    uint32_t* const valuep, struct odict* const parent, char* const key, bool required);
+
+/*
+ * Get a uint16 entry and store it in `*valuep`.
+ */
+enum rawrtc_code dict_get_uint16(
+    uint16_t* const valuep, struct odict* const parent, char* const key, bool required);
+
+/*
+ * Get JSON from stdin and parse it to a dictionary.
+ */
+enum rawrtc_code get_json_stdin(struct odict** const dictp  // de-referenced
+);
+
+/*
+ * Get the ICE role from a string.
+ */
+enum rawrtc_code get_ice_role(
+    enum rawrtc_ice_role* const rolep,  // de-referenced
+    char const* const str);
+
+/*
+ * Get the congestion control algorithm from a string.
+ */
+enum rawrtc_code get_congestion_control_algorithm(
+    enum rawrtc_sctp_transport_congestion_ctrl* const algorithmp,  // de-referenced
+    char const* const str);
+
+/*
+ * Create a data channel helper instance.
+ */
+void data_channel_helper_create(
+    struct data_channel_helper** const channel_helperp,  // de-referenced
+    struct client* const client,
+    char* const label);
+
+/*
+ * Create a data channel helper instance from parameters.
+ */
+void data_channel_helper_create_from_channel(
+    struct data_channel_helper** const channel_helperp,  // de-referenced
+    struct rawrtc_data_channel* channel,
+    struct client* const client,
+    void* const arg  // nullable
+);
+
+/*
+ * Add the ICE candidate to the remote ICE transport if the ICE
+ * candidate type is enabled.
+ */
+void add_to_other_if_ice_candidate_type_enabled(
+    struct client* const client,
+    struct rawrtc_ice_candidate* const candidate,
+    struct rawrtc_ice_transport* const transport);