Multiple Users

SYNC_USER1 declares the first user and password, and must be set. You can optionally declare SYNC_USER2, SYNC_USER3 and so on, if you wish to set up multiple accounts.

Storage Location

The server needs to store a copy of your collection and media in a folder. By default it is ~/.syncserver; you can change this by defining a SYNC_BASE environmental variable. This must not be the same location as your normal Anki data folder, as the server and client must store separate copies.

Public Access

The server listens on an unencrypted HTTP connection, so it's not a good idea to expose it directly to the internet. You'll want to either restrict usage to your local network, or place some form of encryption in front of the server, such as a VPN (Tailscale is apparently easy), or a HTTPS reverse proxy.

You can define SYNC_HOST and SYNC_PORT to change the host and port that the server binds to.

Client Setup

You'll need to determine your computer's network IP address, and then point each of your Anki clients to the address, e.g something like http://192.168.1.200:8080/. The URL can be configured in the preferences.

If you're using AnkiMobile and are unable to connect to a server on your local network, please go into the iOS settings, locate Anki near the bottom, and toggle "Allow Anki to access local network" off and then on again.

Older desktop clients required you to define SYNC_ENDPOINT and SYNC_ENDPOINT_MEDIA. If using an older client, you'd put it as e.g. http://192.168.1.200:8080/sync/ and http://192.168.1.200:8080/msync/ respectively. AnkiDroid clients before 2.16 require separate configuration for the two endpoints.

Reverse Proxies

If using a reverse proxy to provide HTTPS access (e.g. nginx), and binding to a subpath (e.g. http://example.com/custom/ -> http://localhost:8080/), you must make sure to including a trailing slash when configuring Anki. If you put http://example.com/custom instead, it will not work.

On iOS, TLS 1.3 is not supported, so your reverse proxy will need to have TLS 1.2 enabled, or you'll get an "error code -9836".

Large Requests

The standard AnkiWeb limit on uploads is applied by default. You can optionally set MAX_SYNC_PAYLOAD_MEGS to something greater than 100 if you wish to increase the limit. Bear in mind that if you're using a reverse proxy, you may need to adjust the limit there as well.