# Note synchronization

> Cloud-based note data synchronization

Source: https://docs.inkdrop.app/reference/note-synchronization

Inkdrop lets you sync notes across multiple computers via Cloud.
By default, Inkdrop stores your data in Inkdrop sync server.
You can configure synchronizations in the Preferences window like this:

![Sync Preferences](https://docs.inkdrop.app/images/sync_preferences.png)

There are three sync options:

- **Don't Sync** - Store Inkdrop data only in your local computer
- **Inkdrop Sync Server** - Sync with Inkdrop's own service
- **Advanced (CouchDB)** - Sync with your own compatible server

## How to Set Up Your Own Sync Server

Inkdrop lets you store your notes in your own database compatible with [CouchDB](http://couchdb.apache.org/) API instead of Inkdrop's own service.
CouchDB is just another open-source NoSQL database so you can deploy it on your environment for free. See CouchDB's [installation guide](http://docs.couchdb.org/en/1.6.1/install/index.html) for more informations.
Using DBaaS instead of operating database by yourself is good choice. For instance, [Cloudant](https://cloudant.com/) is one of fully-managed DBaaS providers.

> **Warning**
>
> Use this feature at your own risk. Inkdrop itself doesn't protect data from other people on your server. To protect your data, read [Security](#configure-security) section at the bottom of this page.improvements.

### Create a database

Once you got your CouchDB server, let's create a database for storing your notes.
You need only one database for Inkdrop. For example, run below command to create a database:

```bash
> curl -X PUT http://localhost:5984/my-inkdrop-notes
```

> **Note: Note**
>
> If you are running CouchDB not on `localhost` and port 5984 (default), replace `localhost:5984` to your server address and port.

Retrieving the list of databases shows some useful results this time:

```bash
> curl -X GET http://127.0.0.1:5984/_all_dbs
["my-inkdrop-notes"]
```

Return to the Inkdrop sync preferences, you can input the URL to your database to the **Address** section:

```url
http://localhost:5984/my-inkdrop-notes
```

![Sync with custom server on the desktop app](https://docs.inkdrop.app/images/sync_custom-server.png)

Then, push the **Apply** button.

Please read [CouchDB's tutorial](http://guide.couchdb.org/draft/tour.html) for more information.

### Configure security

As you may know, CouchDB is running with the Admin Party by default. It means Everybody has privileges to do anything.
Please read the CouchDB's [documentation](http://guide.couchdb.org/draft/security.html).
To keep your notes secure, we recommend that you create an admin user with a username and password as your credentials.

Now let’s create an admin user. We’ll call her `anna`, and her password is `secret`:

```bash
> curl -X PUT http://127.0.0.1:5984/_config/admins/anna -d '"secret"'
```

Now we have an admin user named `anna`, let's give her an admin access to `my-inkdrop-notes`:

```bash
> curl -X PUT http://127.0.0.1:5984/my-inkdrop-notes/_security -d '{ "admins": { "names": [ "anna" ] } }'
```

It restricts access from people without the valid credentials:

```bash
> curl -X PUT http://127.0.0.1:5984/my-inkdrop-notes
{"error":"unauthorized","reason":"You are not a server admin."}
```

That looks about right. Now we try again with the correct credentials:

```bash
> HOST="http://anna:secret@127.0.0.1:5984"
> curl -X PUT $HOST/my-inkdrop-notes
{"ok":true}
```

Looks good!

Return to the Inkdrop sync preferences, you can input the URL to your database to the **Address** section:

```url
http://anna:secret@127.0.0.1:5984/my-inkdrop-notes
```

Please don't omit the port number.

### Enable SSL

If you would like to make your database accessible to the public, we encourage you to configure SSL.
[CouchDB provides SSL](https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=48203146) by default but it's not recommended since there's a problem with the replication with clients.
We recommend nginx as a reverse-proxy server. Your configuration will look like:

```nginx
server {
  listen 6984;
  ssl on;
  ssl_certificate /path/to/fullchain.pem;
  ssl_certificate_key /path/to/privkey.pem;
  ssl_protocols TLSv1.1 TLSv1.2 SSLv3;
  ssl_session_cache shared:SSL:1m;

  server_name ***;

  location / {
    proxy_pass http://localhost:5984;
    proxy_redirect off;
    proxy_set_header Host $host;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Ssl on;
  }

  location ~ ^/(.*)/_changes {
    proxy_pass http://localhost:5984;
    proxy_redirect off;
    proxy_buffering off;
    proxy_set_header Host $host;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Ssl on;
  }
}
```

Your server URL would be like so:

```url
https://anna:secret@your-server.com:6984/my-inkdrop-notes
```

> **Warning: Note**
>
> You can neither create design documents nor add attachments on the Inkdrop-hosted database.

### Support mobile sync

If you would like to sync your custom database with the mobile app, please create a `design` document on your database:

```js
{
  "_id": "_design/mobile",
  "filters": {
    "sync": "function (doc) { return doc._id.indexOf('file:') === -1 }"
  }
}
```

Also, please don't forget your server to enable SSL because iOS requires it for App Transport Security.

To configure the mobile app to sync with your database:

1. Go to Preferences → Synchronization
2. Select _Advanced (CouchDB)_
3. Input your database URL to the input field at the _ADDRESS_ section.
4. Press _Apply_ button

![Sync with custom server on the mobile app](https://docs.inkdrop.app/images/sync_mobile.png)

## Debugging the database connections

If the app won't sync with the database, there are two ways to debug the issue:

1. Run [Network diagnosis](https://docs.inkdrop.app/reference/troubleshooting#run-network-diagnosis)
2. [Enable main process logging](https://docs.inkdrop.app/reference/troubleshooting#enable-logging)