diff --git a/commit.h b/commit.h
new file mode 100644
index 0000000..4afd27b
--- /dev/null
+++ b/commit.h
@@ -0,0 +1,27 @@
+#ifndef COMMIT_H
+#define COMMIT_H
+
+#include "object.h"
+#include "tree.h"
+
+struct commit_list {
+	struct commit *item;
+	struct commit_list *next;
+};
+
+struct commit {
+	struct object object;
+	unsigned long date;
+	struct commit_list *parents;
+	struct tree *tree;
+};
+
+extern const char *commit_type;
+
+struct commit *lookup_commit(unsigned char *sha1);
+
+int parse_commit(struct commit *item);
+
+void free_commit_list(struct commit_list *list);
+
+#endif /* COMMIT_H */