diff --git a/src/http/modules/ngx_http_grpc_module.c b/src/http/modules/ngx_http_grpc_module.c
index f59ecbd..d4af66d 100644
--- a/src/http/modules/ngx_http_grpc_module.c
+++ b/src/http/modules/ngx_http_grpc_module.c
@@ -27,6 +27,9 @@
     ngx_str_t                  host;
     ngx_uint_t                 host_set;
 
+    ngx_array_t               *grpc_lengths;
+    ngx_array_t               *grpc_values;
+
 #if (NGX_HTTP_SSL)
     ngx_uint_t                 ssl;
     ngx_uint_t                 ssl_protocols;
@@ -119,6 +122,8 @@
     unsigned                   status:1;
 
     ngx_http_request_t        *request;
+
+    ngx_str_t                  host;
 } ngx_http_grpc_ctx_t;
 
 
@@ -135,6 +140,8 @@
 } ngx_http_grpc_frame_t;
 
 
+static ngx_int_t ngx_http_grpc_eval(ngx_http_request_t *r,
+    ngx_http_grpc_ctx_t *ctx, ngx_http_grpc_loc_conf_t *glcf);
 static ngx_int_t ngx_http_grpc_create_request(ngx_http_request_t *r);
 static ngx_int_t ngx_http_grpc_reinit_request(ngx_http_request_t *r);
 static ngx_int_t ngx_http_grpc_body_output_filter(void *data, ngx_chain_t *in);
@@ -524,22 +531,40 @@
         return NGX_HTTP_INTERNAL_SERVER_ERROR;
     }
 
+    ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_grpc_ctx_t));
+    if (ctx == NULL) {
+        return NGX_HTTP_INTERNAL_SERVER_ERROR;
+    }
+
+    ctx->request = r;
+
+    ngx_http_set_ctx(r, ctx, ngx_http_grpc_module);
+
     glcf = ngx_http_get_module_loc_conf(r, ngx_http_grpc_module);
 
     u = r->upstream;
 
-#if (NGX_HTTP_SSL)
-    u->ssl = (glcf->upstream.ssl != NULL);
+    if (glcf->grpc_lengths == NULL) {
+        ctx->host = glcf->host;
 
-    if (u->ssl) {
-        ngx_str_set(&u->schema, "grpcs://");
+#if (NGX_HTTP_SSL)
+        u->ssl = (glcf->upstream.ssl != NULL);
+
+        if (u->ssl) {
+            ngx_str_set(&u->schema, "grpcs://");
+
+        } else {
+            ngx_str_set(&u->schema, "grpc://");
+        }
+#else
+        ngx_str_set(&u->schema, "grpc://");
+#endif
 
     } else {
-        ngx_str_set(&u->schema, "grpc://");
+        if (ngx_http_grpc_eval(r, ctx, glcf) != NGX_OK) {
+            return NGX_HTTP_INTERNAL_SERVER_ERROR;
+        }
     }
-#else
-    ngx_str_set(&u->schema, "grpc://");
-#endif
 
     u->output.tag = (ngx_buf_tag_t) &ngx_http_grpc_module;
 
@@ -551,15 +576,6 @@
     u->abort_request = ngx_http_grpc_abort_request;
     u->finalize_request = ngx_http_grpc_finalize_request;
 
-    ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_grpc_ctx_t));
-    if (ctx == NULL) {
-        return NGX_HTTP_INTERNAL_SERVER_ERROR;
-    }
-
-    ctx->request = r;
-
-    ngx_http_set_ctx(r, ctx, ngx_http_grpc_module);
-
     u->input_filter_init = ngx_http_grpc_filter_init;
     u->input_filter = ngx_http_grpc_filter;
     u->input_filter_ctx = ctx;
@@ -577,6 +593,103 @@
 
 
 static ngx_int_t
+ngx_http_grpc_eval(ngx_http_request_t *r, ngx_http_grpc_ctx_t *ctx,
+    ngx_http_grpc_loc_conf_t *glcf)
+{
+    size_t                add;
+    ngx_url_t             url;
+    ngx_http_upstream_t  *u;
+
+    ngx_memzero(&url, sizeof(ngx_url_t));
+
+    if (ngx_http_script_run(r, &url.url, glcf->grpc_lengths->elts, 0,
+                            glcf->grpc_values->elts)
+        == NULL)
+    {
+        return NGX_ERROR;
+    }
+
+    if (url.url.len > 7
+        && ngx_strncasecmp(url.url.data, (u_char *) "grpc://", 7) == 0)
+    {
+        add = 7;
+
+    } else if (url.url.len > 8
+               && ngx_strncasecmp(url.url.data, (u_char *) "grpcs://", 8) == 0)
+    {
+
+#if (NGX_HTTP_SSL)
+        add = 8;
+        r->upstream->ssl = 1;
+#else
+        ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
+                      "grpcs protocol requires SSL support");
+        return NGX_ERROR;
+#endif
+
+    } else {
+        add = 0;
+    }
+
+    u = r->upstream;
+
+    if (add) {
+        u->schema.len = add;
+        u->schema.data = url.url.data;
+
+        url.url.data += add;
+        url.url.len -= add;
+
+    } else {
+        ngx_str_set(&u->schema, "grpc://");
+    }
+
+    url.no_resolve = 1;
+
+    if (ngx_parse_url(r->pool, &url) != NGX_OK) {
+        if (url.err) {
+            ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
+                          "%s in upstream \"%V\"", url.err, &url.url);
+        }
+
+        return NGX_ERROR;
+    }
+
+    u->resolved = ngx_pcalloc(r->pool, sizeof(ngx_http_upstream_resolved_t));
+    if (u->resolved == NULL) {
+        return NGX_ERROR;
+    }
+
+    if (url.addrs) {
+        u->resolved->sockaddr = url.addrs[0].sockaddr;
+        u->resolved->socklen = url.addrs[0].socklen;
+        u->resolved->name = url.addrs[0].name;
+        u->resolved->naddrs = 1;
+    }
+
+    u->resolved->host = url.host;
+    u->resolved->port = url.port;
+    u->resolved->no_port = url.no_port;
+
+    if (url.family != AF_UNIX) {
+
+        if (url.no_port) {
+            ctx->host = url.host;
+
+        } else {
+            ctx->host.len = url.host.len + 1 + url.port_text.len;
+            ctx->host.data = url.host.data;
+        }
+
+    } else {
+        ngx_str_set(&ctx->host, "localhost");
+    }
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t
 ngx_http_grpc_create_request(ngx_http_request_t *r)
 {
     u_char                       *p, *tmp, *key_tmp, *val_tmp, *headers_frame;
@@ -587,6 +700,7 @@
     ngx_chain_t                  *cl, *body;
     ngx_list_part_t              *part;
     ngx_table_elt_t              *header;
+    ngx_http_grpc_ctx_t          *ctx;
     ngx_http_upstream_t          *u;
     ngx_http_grpc_frame_t        *f;
     ngx_http_script_code_pt       code;
@@ -598,6 +712,8 @@
 
     glcf = ngx_http_get_module_loc_conf(r, ngx_http_grpc_module);
 
+    ctx = ngx_http_get_module_ctx(r, ngx_http_grpc_module);
+
     len = sizeof(ngx_http_grpc_connection_start) - 1
           + sizeof(ngx_http_grpc_frame_t);             /* headers frame */
 
@@ -637,10 +753,10 @@
     /* :authority header */
 
     if (!glcf->host_set) {
-        len += 1 + NGX_HTTP_V2_INT_OCTETS + glcf->host.len;
+        len += 1 + NGX_HTTP_V2_INT_OCTETS + ctx->host.len;
 
-        if (tmp_len < glcf->host.len) {
-            tmp_len = glcf->host.len;
+        if (tmp_len < ctx->host.len) {
+            tmp_len = ctx->host.len;
         }
     }
 
@@ -785,7 +901,7 @@
     }
 
 #if (NGX_HTTP_SSL)
-    if (glcf->ssl) {
+    if (u->ssl) {
         *b->last++ = ngx_http_v2_indexed(NGX_HTTP_V2_SCHEME_HTTPS_INDEX);
 
         ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
@@ -846,11 +962,11 @@
 
     if (!glcf->host_set) {
         *b->last++ = ngx_http_v2_inc_indexed(NGX_HTTP_V2_AUTHORITY_INDEX);
-        b->last = ngx_http_v2_write_value(b->last, glcf->host.data,
-                                          glcf->host.len, tmp);
+        b->last = ngx_http_v2_write_value(b->last, ctx->host.data,
+                                          ctx->host.len, tmp);
 
         ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
-                       "grpc header: \":authority: %V\"", &glcf->host);
+                       "grpc header: \":authority: %V\"", &ctx->host);
     }
 
     ngx_memzero(&e, sizeof(ngx_http_script_engine_t));
@@ -4319,15 +4435,23 @@
 
     clcf = ngx_http_conf_get_module_loc_conf(cf, ngx_http_core_module);
 
-    if (clcf->noname && conf->upstream.upstream == NULL) {
+    if (clcf->noname
+        && conf->upstream.upstream == NULL && conf->grpc_lengths == NULL)
+    {
         conf->upstream.upstream = prev->upstream.upstream;
         conf->host = prev->host;
+
+        conf->grpc_lengths = prev->grpc_lengths;
+        conf->grpc_values = prev->grpc_values;
+
 #if (NGX_HTTP_SSL)
         conf->upstream.ssl = prev->upstream.ssl;
 #endif
     }
 
-    if (clcf->lmt_excpt && clcf->handler == NULL && conf->upstream.upstream) {
+    if (clcf->lmt_excpt && clcf->handler == NULL
+        && (conf->upstream.upstream || conf->grpc_lengths))
+    {
         clcf->handler = ngx_http_grpc_handler;
     }
 
@@ -4537,18 +4661,54 @@
 {
     ngx_http_grpc_loc_conf_t *glcf = conf;
 
-    size_t                     add;
-    ngx_str_t                 *value, *url;
-    ngx_url_t                  u;
-    ngx_http_core_loc_conf_t  *clcf;
+    size_t                      add;
+    ngx_str_t                  *value, *url;
+    ngx_url_t                   u;
+    ngx_uint_t                  n;
+    ngx_http_core_loc_conf_t   *clcf;
+    ngx_http_script_compile_t   sc;
 
-    if (glcf->upstream.upstream) {
+    if (glcf->upstream.upstream || glcf->grpc_lengths) {
         return "is duplicate";
     }
 
+    clcf = ngx_http_conf_get_module_loc_conf(cf, ngx_http_core_module);
+
+    clcf->handler = ngx_http_grpc_handler;
+
+    if (clcf->name.len && clcf->name.data[clcf->name.len - 1] == '/') {
+        clcf->auto_redirect = 1;
+    }
+
     value = cf->args->elts;
+
     url = &value[1];
 
+    n = ngx_http_script_variables_count(url);
+
+    if (n) {
+
+        ngx_memzero(&sc, sizeof(ngx_http_script_compile_t));
+
+        sc.cf = cf;
+        sc.source = url;
+        sc.lengths = &glcf->grpc_lengths;
+        sc.values = &glcf->grpc_values;
+        sc.variables = n;
+        sc.complete_lengths = 1;
+        sc.complete_values = 1;
+
+        if (ngx_http_script_compile(&sc) != NGX_OK) {
+            return NGX_CONF_ERROR;
+        }
+
+#if (NGX_HTTP_SSL)
+        glcf->ssl = 1;
+#endif
+
+        return NGX_CONF_OK;
+    }
+
     if (ngx_strncasecmp(url->data, (u_char *) "grpc://", 7) == 0) {
         add = 7;
 
@@ -4593,14 +4753,6 @@
         ngx_str_set(&glcf->host, "localhost");
     }
 
-    clcf = ngx_http_conf_get_module_loc_conf(cf, ngx_http_core_module);
-
-    clcf->handler = ngx_http_grpc_handler;
-
-    if (clcf->name.len && clcf->name.data[clcf->name.len - 1] == '/') {
-        clcf->auto_redirect = 1;
-    }
-
     return NGX_CONF_OK;
 }