Enabling Redis for PHP on Synology NAS (Manual Method)

This page describes how to manually enable Redis support for PHP (v8.2) on a Synology NAS using the built-in PHP package and Docker-based Redis server.

Background

Synology does not officially include the `redis` PHP extension in its default PHP packages. Attempting to use Redis from PHP results in the following fatal error:

Fatal error: Uncaught Error: Class "Redis" not found

Prerequisites

PHP 8.2 installed from Synology Package Center.
A running Redis server (e.g., using Docker or a separate host).
SSH access to your Synology NAS.
Redis PHP extension installed manually or available (e.g., copied from PECL build).

Solution

To make Synology's PHP interpreter recognize the Redis extension, you need to manually add it to the `extension_list.json` file used by Synology’s PHP infrastructure.

Steps

SSH into your NAS.
Open the PHP 8.2 extension configuration file:

sudo vi /volume1/@appstore/PHP8.2/misc/extension_list.json

Add the following block at the end of the JSON list (inside the outermost `{}`):

    ,
    "redis": {
        "enable_default": false,
        "desc": "This module is not officially supported by Synology and may be removed by updates"
    }

Save the file and exit the editor.

Important Notes

The Redis extension must already be available in the appropriate PHP `ext` directory (e.g., `/var/packages/PHP8.2/target/usr/local/lib/php82/modules/redis.so`).
After modifying `extension_list.json`, go to **Web Station** or **PHP Settings** and enable the `redis` extension.
This configuration may be **overwritten by DSM updates**, so it should be re-checked after system upgrades.

Source

Synology Community Forum thread: https://community.synology.com/enu/forum/69/post/161908

Status

Tested working as of May 2025 on DSM 7.x and PHP 8.2.