diff --git a/crypto_api.h b/crypto_api.h
new file mode 100644
index 0000000..633463d
--- /dev/null
+++ b/crypto_api.h
@@ -0,0 +1,43 @@
+/* $OpenBSD: crypto_api.h,v 1.1 2013/12/06 13:39:49 markus Exp $ */
+
+/* Placed in the public domain. */
+
+#ifndef crypto_api_h
+#define crypto_api_h
+
+#include <stdint.h>
+#include <stdlib.h>
+
+typedef int32_t crypto_int32;
+typedef uint32_t crypto_uint32;
+
+#define randombytes(buf, buf_len) arc4random_buf((buf), (buf_len))
+
+#define crypto_hashblocks_sha512_STATEBYTES 64U
+#define crypto_hashblocks_sha512_BLOCKBYTES 128U
+
+int	crypto_hashblocks_sha512(unsigned char *, const unsigned char *,
+     unsigned long long);
+
+#define crypto_hash_sha512_BYTES 64U
+
+int	crypto_hash_sha512(unsigned char *, const unsigned char *,
+    unsigned long long);
+
+int	crypto_verify_32(const unsigned char *, const unsigned char *);
+
+#define crypto_sign_BYTES crypto_sign_ed25519_BYTES
+#define crypto_sign_PUBLICKEYBYTES crypto_sign_ed25519_PUBLICKEYBYTES
+#define crypto_sign_SECRETKEYBYTES crypto_sign_ed25519_SECRETKEYBYTES
+
+#define crypto_sign_ed25519_SECRETKEYBYTES 64U
+#define crypto_sign_ed25519_PUBLICKEYBYTES 32U
+#define crypto_sign_ed25519_BYTES 64U
+
+int	crypto_sign_ed25519(unsigned char *, unsigned long long *,
+    const unsigned char *, unsigned long long, const unsigned char *);
+int	crypto_sign_ed25519_open(unsigned char *, unsigned long long *,
+    const unsigned char *, unsigned long long, const unsigned char *);
+int	crypto_sign_ed25519_keypair(unsigned char *, unsigned char *);
+
+#endif /* crypto_api_h */