diff --git a/src/php/ext/grpc/call.c b/src/php/ext/grpc/call.c
index be07190..48a374f 100644
--- a/src/php/ext/grpc/call.c
+++ b/src/php/ext/grpc/call.c
@@ -104,7 +104,8 @@
     str_key = ecalloc(key_len + 1, sizeof(char));
     memcpy(str_key, GRPC_SLICE_START_PTR(elem->key), key_len);
     str_val = ecalloc(GRPC_SLICE_LENGTH(elem->value) + 1, sizeof(char));
-    memcpy(str_val, GRPC_SLICE_START_PTR(elem->value), GRPC_SLICE_LENGTH(elem->value));
+    memcpy(str_val, GRPC_SLICE_START_PTR(elem->value),
+           GRPC_SLICE_LENGTH(elem->value));
     if (php_grpc_zend_hash_find(array_hash, str_key, key_len, (void **)&data)
         == SUCCESS) {
       if (Z_TYPE_P(data) != IS_ARRAY) {
@@ -115,7 +116,8 @@
         efree(str_val);
         return NULL;
       }
-      php_grpc_add_next_index_stringl(data, str_val, GRPC_SLICE_LENGTH(elem->value),
+      php_grpc_add_next_index_stringl(data, str_val,
+                                      GRPC_SLICE_LENGTH(elem->value),
                                       false);
     } else {
       PHP_GRPC_MAKE_STD_ZVAL(inner_array);
@@ -172,8 +174,10 @@
       if (Z_TYPE_P(value) != IS_STRING) {
         return false;
       }
-      metadata->metadata[metadata->count].key = grpc_slice_from_copied_string(key1);
-      metadata->metadata[metadata->count].value = grpc_slice_from_copied_buffer(Z_STRVAL_P(value), Z_STRLEN_P(value));
+      metadata->metadata[metadata->count].key =
+        grpc_slice_from_copied_string(key1);
+      metadata->metadata[metadata->count].value =
+        grpc_slice_from_copied_buffer(Z_STRVAL_P(value), Z_STRLEN_P(value));
       metadata->count += 1;
     PHP_GRPC_HASH_FOREACH_END()
   PHP_GRPC_HASH_FOREACH_END()
@@ -233,7 +237,8 @@
       grpc_slice_from_copied_string(host_override) : grpc_empty_slice();
   call->wrapped =
     grpc_channel_create_call(channel->wrapped, NULL, GRPC_PROPAGATE_DEFAULTS,
-                             completion_queue, method_slice, host_override != NULL ? &host_slice : NULL,
+                             completion_queue, method_slice,
+                             host_override != NULL ? &host_slice : NULL,
                              deadline->wrapped, NULL);
   grpc_slice_unref(method_slice);
   grpc_slice_unref(host_slice);
@@ -384,8 +389,10 @@
                                1 TSRMLS_CC);
           goto cleanup;
         }
-        send_status_details = grpc_slice_from_copied_string(Z_STRVAL_P(inner_value));
-        ops[op_num].data.send_status_from_server.status_details = &send_status_details;
+        send_status_details = grpc_slice_from_copied_string(
+          Z_STRVAL_P(inner_value));
+        ops[op_num].data.send_status_from_server.status_details =
+          &send_status_details;
       } else {
         zend_throw_exception(spl_ce_InvalidArgumentException,
                              "String status details is required",
@@ -557,12 +564,33 @@
   RETURN_LONG(error);
 }
 
+ZEND_BEGIN_ARG_INFO_EX(arginfo_construct, 0, 0, 3)
+  ZEND_ARG_INFO(0, channel)
+  ZEND_ARG_INFO(0, method)
+  ZEND_ARG_INFO(0, deadline)
+  ZEND_ARG_INFO(0, host_override)
+ZEND_END_ARG_INFO()
+
+ZEND_BEGIN_ARG_INFO_EX(arginfo_startBatch, 0, 0, 1)
+  ZEND_ARG_INFO(0, ops)
+ZEND_END_ARG_INFO()
+
+ZEND_BEGIN_ARG_INFO_EX(arginfo_getPeer, 0, 0, 0)
+ZEND_END_ARG_INFO()
+
+ZEND_BEGIN_ARG_INFO_EX(arginfo_cancel, 0, 0, 0)
+ZEND_END_ARG_INFO()
+
+ZEND_BEGIN_ARG_INFO_EX(arginfo_setCredentials, 0, 0, 1)
+  ZEND_ARG_INFO(0, credentials)
+ZEND_END_ARG_INFO()
+
 static zend_function_entry call_methods[] = {
-  PHP_ME(Call, __construct, NULL, ZEND_ACC_PUBLIC | ZEND_ACC_CTOR)
-  PHP_ME(Call, startBatch, NULL, ZEND_ACC_PUBLIC)
-  PHP_ME(Call, getPeer, NULL, ZEND_ACC_PUBLIC)
-  PHP_ME(Call, cancel, NULL, ZEND_ACC_PUBLIC)
-  PHP_ME(Call, setCredentials, NULL, ZEND_ACC_PUBLIC)
+  PHP_ME(Call, __construct, arginfo_construct, ZEND_ACC_PUBLIC | ZEND_ACC_CTOR)
+  PHP_ME(Call, startBatch, arginfo_startBatch, ZEND_ACC_PUBLIC)
+  PHP_ME(Call, getPeer, arginfo_getPeer, ZEND_ACC_PUBLIC)
+  PHP_ME(Call, cancel, arginfo_cancel, ZEND_ACC_PUBLIC)
+  PHP_ME(Call, setCredentials, arginfo_setCredentials, ZEND_ACC_PUBLIC)
   PHP_FE_END
 };
 
diff --git a/src/php/ext/grpc/call_credentials.c b/src/php/ext/grpc/call_credentials.c
index 043817f..625c0c6 100644
--- a/src/php/ext/grpc/call_credentials.c
+++ b/src/php/ext/grpc/call_credentials.c
@@ -212,10 +212,19 @@
   efree(state);
 }
 
+ZEND_BEGIN_ARG_INFO_EX(arginfo_createComposite, 0, 0, 2)
+  ZEND_ARG_INFO(0, creds1)
+  ZEND_ARG_INFO(0, creds2)
+ZEND_END_ARG_INFO()
+
+ZEND_BEGIN_ARG_INFO_EX(arginfo_createFromPlugin, 0, 0, 1)
+  ZEND_ARG_INFO(0, callback)
+ZEND_END_ARG_INFO()
+
 static zend_function_entry call_credentials_methods[] = {
-  PHP_ME(CallCredentials, createComposite, NULL,
+  PHP_ME(CallCredentials, createComposite, arginfo_createComposite,
          ZEND_ACC_PUBLIC | ZEND_ACC_STATIC)
-  PHP_ME(CallCredentials, createFromPlugin, NULL,
+  PHP_ME(CallCredentials, createFromPlugin, arginfo_createFromPlugin,
          ZEND_ACC_PUBLIC | ZEND_ACC_STATIC)
   PHP_FE_END
 };
diff --git a/src/php/ext/grpc/channel.c b/src/php/ext/grpc/channel.c
index 4ce4f30..c26fe4a 100644
--- a/src/php/ext/grpc/channel.c
+++ b/src/php/ext/grpc/channel.c
@@ -243,12 +243,37 @@
   }
 }
 
+ZEND_BEGIN_ARG_INFO_EX(arginfo_construct, 0, 0, 2)
+  ZEND_ARG_INFO(0, target)
+  ZEND_ARG_INFO(0, args)
+ZEND_END_ARG_INFO()
+
+ZEND_BEGIN_ARG_INFO_EX(arginfo_getTarget, 0, 0, 0)
+ZEND_END_ARG_INFO()
+
+ZEND_BEGIN_ARG_INFO_EX(arginfo_getConnectivityState, 0, 0, 0)
+  ZEND_ARG_INFO(0, try_to_connect)
+ZEND_END_ARG_INFO()
+
+ZEND_BEGIN_ARG_INFO_EX(arginfo_watchConnectivityState, 0, 0, 2)
+  ZEND_ARG_INFO(0, last_state)
+  ZEND_ARG_INFO(0, deadline)
+ZEND_END_ARG_INFO()
+
+ZEND_BEGIN_ARG_INFO_EX(arginfo_close, 0, 0, 0)
+ZEND_END_ARG_INFO()
+
 static zend_function_entry channel_methods[] = {
-  PHP_ME(Channel, __construct, NULL, ZEND_ACC_PUBLIC | ZEND_ACC_CTOR)
-  PHP_ME(Channel, getTarget, NULL, ZEND_ACC_PUBLIC)
-  PHP_ME(Channel, getConnectivityState, NULL, ZEND_ACC_PUBLIC)
-  PHP_ME(Channel, watchConnectivityState, NULL, ZEND_ACC_PUBLIC)
-  PHP_ME(Channel, close, NULL, ZEND_ACC_PUBLIC)
+  PHP_ME(Channel, __construct, arginfo_construct,
+         ZEND_ACC_PUBLIC | ZEND_ACC_CTOR)
+  PHP_ME(Channel, getTarget, arginfo_getTarget,
+         ZEND_ACC_PUBLIC)
+  PHP_ME(Channel, getConnectivityState, arginfo_getConnectivityState,
+         ZEND_ACC_PUBLIC)
+  PHP_ME(Channel, watchConnectivityState, arginfo_watchConnectivityState,
+         ZEND_ACC_PUBLIC)
+  PHP_ME(Channel, close, arginfo_close,
+         ZEND_ACC_PUBLIC)
   PHP_FE_END
 };
 
diff --git a/src/php/ext/grpc/channel_credentials.c b/src/php/ext/grpc/channel_credentials.c
index 36a8223..2160a54 100644
--- a/src/php/ext/grpc/channel_credentials.c
+++ b/src/php/ext/grpc/channel_credentials.c
@@ -199,16 +199,37 @@
   RETURN_NULL();
 }
 
+ZEND_BEGIN_ARG_INFO_EX(arginfo_setDefaultRootsPem, 0, 0, 1)
+  ZEND_ARG_INFO(0, pem_roots)
+ZEND_END_ARG_INFO()
+
+ZEND_BEGIN_ARG_INFO_EX(arginfo_createDefault, 0, 0, 0)
+ZEND_END_ARG_INFO()
+
+ZEND_BEGIN_ARG_INFO_EX(arginfo_createSsl, 0, 0, 0)
+  ZEND_ARG_INFO(0, pem_root_certs)
+  ZEND_ARG_INFO(0, pem_private_key)
+  ZEND_ARG_INFO(0, pem_cert_chain)
+ZEND_END_ARG_INFO()
+
+ZEND_BEGIN_ARG_INFO_EX(arginfo_createComposite, 0, 0, 2)
+  ZEND_ARG_INFO(0, channel_creds)
+  ZEND_ARG_INFO(0, call_creds)
+ZEND_END_ARG_INFO()
+
+ZEND_BEGIN_ARG_INFO_EX(arginfo_createInsecure, 0, 0, 0)
+ZEND_END_ARG_INFO()
+
 static zend_function_entry channel_credentials_methods[] = {
-  PHP_ME(ChannelCredentials, setDefaultRootsPem, NULL,
+  PHP_ME(ChannelCredentials, setDefaultRootsPem, arginfo_setDefaultRootsPem,
          ZEND_ACC_PUBLIC | ZEND_ACC_STATIC)
-  PHP_ME(ChannelCredentials, createDefault, NULL,
+  PHP_ME(ChannelCredentials, createDefault, arginfo_createDefault,
          ZEND_ACC_PUBLIC | ZEND_ACC_STATIC)
-  PHP_ME(ChannelCredentials, createSsl, NULL,
+  PHP_ME(ChannelCredentials, createSsl, arginfo_createSsl,
          ZEND_ACC_PUBLIC | ZEND_ACC_STATIC)
-  PHP_ME(ChannelCredentials, createComposite, NULL,
+  PHP_ME(ChannelCredentials, createComposite, arginfo_createComposite,
          ZEND_ACC_PUBLIC | ZEND_ACC_STATIC)
-  PHP_ME(ChannelCredentials, createInsecure, NULL,
+  PHP_ME(ChannelCredentials, createInsecure, arginfo_createInsecure,
          ZEND_ACC_PUBLIC | ZEND_ACC_STATIC)
   PHP_FE_END
 };
diff --git a/src/php/ext/grpc/server.c b/src/php/ext/grpc/server.c
index 9ac5d2a..87780e9 100644
--- a/src/php/ext/grpc/server.c
+++ b/src/php/ext/grpc/server.c
@@ -116,8 +116,6 @@
 
 /**
  * Request a call on a server. Creates a single GRPC_SERVER_RPC_NEW event.
- * @param long $tag_new The tag to associate with the new request
- * @param long $tag_cancel The tag to use if the call is cancelled
  * @return void
  */
 PHP_METHOD(Server, requestCall) {
@@ -239,12 +237,36 @@
   grpc_server_start(server->wrapped);
 }
 
+ZEND_BEGIN_ARG_INFO_EX(arginfo_construct, 0, 0, 0)
+  ZEND_ARG_INFO(0, args)
+ZEND_END_ARG_INFO()
+
+ZEND_BEGIN_ARG_INFO_EX(arginfo_requestCall, 0, 0, 0)
+ZEND_END_ARG_INFO()
+
+ZEND_BEGIN_ARG_INFO_EX(arginfo_addHttp2Port, 0, 0, 1)
+  ZEND_ARG_INFO(0, addr)
+ZEND_END_ARG_INFO()
+
+ZEND_BEGIN_ARG_INFO_EX(arginfo_addSecureHttp2Port, 0, 0, 2)
+  ZEND_ARG_INFO(0, addr)
+  ZEND_ARG_INFO(0, server_creds)
+ZEND_END_ARG_INFO()
+
+ZEND_BEGIN_ARG_INFO_EX(arginfo_start, 0, 0, 0)
+ZEND_END_ARG_INFO()
+
 static zend_function_entry server_methods[] = {
-  PHP_ME(Server, __construct, NULL, ZEND_ACC_PUBLIC | ZEND_ACC_CTOR)
-  PHP_ME(Server, requestCall, NULL, ZEND_ACC_PUBLIC)
-  PHP_ME(Server, addHttp2Port, NULL, ZEND_ACC_PUBLIC)
-  PHP_ME(Server, addSecureHttp2Port, NULL, ZEND_ACC_PUBLIC)
-  PHP_ME(Server, start, NULL, ZEND_ACC_PUBLIC)
+  PHP_ME(Server, __construct, arginfo_construct,
+         ZEND_ACC_PUBLIC | ZEND_ACC_CTOR)
+  PHP_ME(Server, requestCall, arginfo_requestCall,
+         ZEND_ACC_PUBLIC)
+  PHP_ME(Server, addHttp2Port, arginfo_addHttp2Port,
+         ZEND_ACC_PUBLIC)
+  PHP_ME(Server, addSecureHttp2Port, arginfo_addSecureHttp2Port,
+         ZEND_ACC_PUBLIC)
+  PHP_ME(Server, start, arginfo_start,
+         ZEND_ACC_PUBLIC)
   PHP_FE_END
 };
 
diff --git a/src/php/ext/grpc/server_credentials.c b/src/php/ext/grpc/server_credentials.c
index 3e39fee..ec29dfd 100644
--- a/src/php/ext/grpc/server_credentials.c
+++ b/src/php/ext/grpc/server_credentials.c
@@ -117,8 +117,14 @@
   RETURN_DESTROY_ZVAL(creds_object);
 }
 
+ZEND_BEGIN_ARG_INFO_EX(arginfo_createSsl, 0, 0, 3)
+  ZEND_ARG_INFO(0, pem_root_certs)
+  ZEND_ARG_INFO(0, pem_private_key)
+  ZEND_ARG_INFO(0, pem_cert_chain)
+ZEND_END_ARG_INFO()
+
 static zend_function_entry server_credentials_methods[] = {
-  PHP_ME(ServerCredentials, createSsl, NULL,
+  PHP_ME(ServerCredentials, createSsl, arginfo_createSsl,
          ZEND_ACC_PUBLIC | ZEND_ACC_STATIC)
   PHP_FE_END
  };
diff --git a/src/php/ext/grpc/timeval.c b/src/php/ext/grpc/timeval.c
index 7ada915..78c29e3 100644
--- a/src/php/ext/grpc/timeval.c
+++ b/src/php/ext/grpc/timeval.c
@@ -245,17 +245,65 @@
   gpr_sleep_until(this->wrapped);
 }
 
+ZEND_BEGIN_ARG_INFO_EX(arginfo_construct, 0, 0, 1)
+  ZEND_ARG_INFO(0, microseconds)
+ZEND_END_ARG_INFO()
+
+ZEND_BEGIN_ARG_INFO_EX(arginfo_add, 0, 0, 1)
+  ZEND_ARG_INFO(0, timeval)
+ZEND_END_ARG_INFO()
+
+ZEND_BEGIN_ARG_INFO_EX(arginfo_compare, 0, 0, 2)
+  ZEND_ARG_INFO(0, a_timeval)
+  ZEND_ARG_INFO(0, b_timeval)
+ZEND_END_ARG_INFO()
+
+ZEND_BEGIN_ARG_INFO_EX(arginfo_infFuture, 0, 0, 0)
+ZEND_END_ARG_INFO()
+
+ZEND_BEGIN_ARG_INFO_EX(arginfo_infPast, 0, 0, 0)
+ZEND_END_ARG_INFO()
+
+ZEND_BEGIN_ARG_INFO_EX(arginfo_now, 0, 0, 0)
+ZEND_END_ARG_INFO()
+
+ZEND_BEGIN_ARG_INFO_EX(arginfo_similar, 0, 0, 3)
+  ZEND_ARG_INFO(0, a_timeval)
+  ZEND_ARG_INFO(0, b_timeval)
+  ZEND_ARG_INFO(0, threshold_timeval)
+ZEND_END_ARG_INFO()
+
+ZEND_BEGIN_ARG_INFO_EX(arginfo_sleepUntil, 0, 0, 0)
+ZEND_END_ARG_INFO()
+
+ZEND_BEGIN_ARG_INFO_EX(arginfo_subtract, 0, 0, 1)
+  ZEND_ARG_INFO(0, timeval)
+ZEND_END_ARG_INFO()
+
+ZEND_BEGIN_ARG_INFO_EX(arginfo_zero, 0, 0, 0)
+ZEND_END_ARG_INFO()
+
 static zend_function_entry timeval_methods[] = {
-  PHP_ME(Timeval, __construct, NULL, ZEND_ACC_PUBLIC | ZEND_ACC_CTOR)
-  PHP_ME(Timeval, add, NULL, ZEND_ACC_PUBLIC)
-  PHP_ME(Timeval, compare, NULL, ZEND_ACC_PUBLIC | ZEND_ACC_STATIC)
-  PHP_ME(Timeval, infFuture, NULL, ZEND_ACC_PUBLIC | ZEND_ACC_STATIC)
-  PHP_ME(Timeval, infPast, NULL, ZEND_ACC_PUBLIC | ZEND_ACC_STATIC)
-  PHP_ME(Timeval, now, NULL, ZEND_ACC_PUBLIC | ZEND_ACC_STATIC)
-  PHP_ME(Timeval, similar, NULL, ZEND_ACC_PUBLIC | ZEND_ACC_STATIC)
-  PHP_ME(Timeval, sleepUntil, NULL, ZEND_ACC_PUBLIC)
-  PHP_ME(Timeval, subtract, NULL, ZEND_ACC_PUBLIC)
-  PHP_ME(Timeval, zero, NULL, ZEND_ACC_PUBLIC | ZEND_ACC_STATIC)
+  PHP_ME(Timeval, __construct, arginfo_construct,
+         ZEND_ACC_PUBLIC | ZEND_ACC_CTOR)
+  PHP_ME(Timeval, add, arginfo_add,
+         ZEND_ACC_PUBLIC)
+  PHP_ME(Timeval, compare, arginfo_compare,
+         ZEND_ACC_PUBLIC | ZEND_ACC_STATIC)
+  PHP_ME(Timeval, infFuture, arginfo_infFuture,
+         ZEND_ACC_PUBLIC | ZEND_ACC_STATIC)
+  PHP_ME(Timeval, infPast, arginfo_infPast,
+         ZEND_ACC_PUBLIC | ZEND_ACC_STATIC)
+  PHP_ME(Timeval, now, arginfo_now,
+         ZEND_ACC_PUBLIC | ZEND_ACC_STATIC)
+  PHP_ME(Timeval, similar, arginfo_similar,
+         ZEND_ACC_PUBLIC | ZEND_ACC_STATIC)
+  PHP_ME(Timeval, sleepUntil, arginfo_sleepUntil,
+         ZEND_ACC_PUBLIC)
+  PHP_ME(Timeval, subtract, arginfo_subtract,
+         ZEND_ACC_PUBLIC)
+  PHP_ME(Timeval, zero, arginfo_zero,
+         ZEND_ACC_PUBLIC | ZEND_ACC_STATIC)
   PHP_FE_END
 };