new file mode 100644
--- /dev/null
+++ b/src/http/v3/ngx_http_v3.h
@@ -0,0 +1,89 @@
+
+/*
+ * Copyright (C) Roman Arutyunyan
+ * Copyright (C) Nginx, Inc.
+ */
+
+
+#ifndef _NGX_HTTP_V3_H_INCLUDED_
+#define _NGX_HTTP_V3_H_INCLUDED_
+
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+#include <ngx_http.h>
+
+
+#define NGX_HTTP_V3_STREAM             0x48335354   /* "H3ST" */
+
+
+#define NGX_HTTP_V3_VARLEN_INT_LEN     4
+#define NGX_HTTP_V3_PREFIX_INT_LEN     11
+
+
+typedef struct {
+    ngx_http_connection_t   hc;
+
+    ngx_array_t            *dynamic;
+
+    ngx_connection_t       *client_encoder;
+    ngx_connection_t       *client_decoder;
+    ngx_connection_t       *server_encoder;
+    ngx_connection_t       *server_decoder;
+} ngx_http_v3_connection_t;
+
+
+typedef struct {
+    ngx_str_t               name;
+    ngx_str_t               value;
+} ngx_http_v3_header_t;
+
+
+ngx_int_t ngx_http_v3_parse_header(ngx_http_request_t *r, ngx_buf_t *b,
+    ngx_uint_t pseudo);
+ngx_chain_t *ngx_http_v3_create_header(ngx_http_request_t *r);
+
+
+uintptr_t ngx_http_v3_encode_varlen_int(u_char *p, uint64_t value);
+uintptr_t ngx_http_v3_encode_prefix_int(u_char *p, uint64_t value,
+    ngx_uint_t prefix);
+uint64_t ngx_http_v3_decode_varlen_int(u_char *p);
+int64_t ngx_http_v3_decode_prefix_int(u_char **src, size_t len,
+    ngx_uint_t prefix);
+ngx_int_t ngx_http_v3_decode_huffman(ngx_connection_t *c, ngx_str_t *s);
+
+void ngx_http_v3_handle_client_uni_stream(ngx_connection_t *c);
+
+ngx_int_t ngx_http_v3_ref_insert(ngx_connection_t *c, ngx_uint_t dynamic,
+    ngx_uint_t index, ngx_str_t *value);
+ngx_int_t ngx_http_v3_insert(ngx_connection_t *c, ngx_str_t *name,
+    ngx_str_t *value);
+ngx_int_t ngx_http_v3_set_capacity(ngx_connection_t *c, ngx_uint_t capacity);
+ngx_int_t ngx_http_v3_duplicate(ngx_connection_t *c, ngx_uint_t index);
+ngx_int_t ngx_http_v3_ack_header(ngx_connection_t *c, ngx_uint_t stream_id);
+ngx_int_t ngx_http_v3_cancel_stream(ngx_connection_t *c, ngx_uint_t stream_id);
+ngx_int_t ngx_http_v3_inc_insert_count(ngx_connection_t *c, ngx_uint_t inc);
+ngx_http_v3_header_t *ngx_http_v3_lookup_table(ngx_connection_t *c,
+    ngx_uint_t dynamic, ngx_uint_t index);
+ngx_int_t ngx_http_v3_check_insert_count(ngx_connection_t *c,
+    ngx_uint_t insert_count);
+
+ngx_int_t ngx_http_v3_client_ref_insert(ngx_connection_t *c, ngx_uint_t dynamic,
+    ngx_uint_t index, ngx_str_t *value);
+ngx_int_t ngx_http_v3_client_insert(ngx_connection_t *c, ngx_str_t *name,
+    ngx_str_t *value);
+ngx_int_t ngx_http_v3_client_set_capacity(ngx_connection_t *c,
+    ngx_uint_t capacity);
+ngx_int_t ngx_http_v3_client_duplicate(ngx_connection_t *c, ngx_uint_t index);
+ngx_int_t ngx_http_v3_client_ack_header(ngx_connection_t *c,
+    ngx_uint_t stream_id);
+ngx_int_t ngx_http_v3_client_cancel_stream(ngx_connection_t *c,
+    ngx_uint_t stream_id);
+ngx_int_t ngx_http_v3_client_inc_insert_count(ngx_connection_t *c,
+    ngx_uint_t inc);
+
+
+extern ngx_module_t  ngx_http_v3_module;
+
+
+#endif /* _NGX_HTTP_V3_H_INCLUDED_ */