> For the complete documentation index, see [llms.txt](https://documentation.opencats.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://documentation.opencats.org/installation/run-the-installer.md).

# Run the Installer

After the web server, PHP, MariaDB database, OpenCATS files, and directory permissions are ready, open OpenCATS in your browser.

For a local installation, use:

```
http://localhost/opencats/
```

For a server or VPS, use the hostname and path you configured.

## If the installer does not start

OpenCATS starts the installer when `INSTALL_BLOCK` is missing. If you are doing a first-time installation and the installer does not appear, check whether `INSTALL_BLOCK` exists in the OpenCATS directory and remove it only for the installation step.

After installation or upgrade, confirm `INSTALL_BLOCK` exists again so the installer is not exposed.

## Database connectivity

Enter the MariaDB database name, user, password, and host you created during installation.

Common host values:

* `localhost` for a normal local Linux or Windows stack.
* `opencatsdb` for the repository Docker Compose development environment.
* A hosting-provider database hostname for shared hosting or managed database services.

Use the installer database connectivity test before continuing. If the test fails, confirm:

* the database exists;
* the database user has privileges on that database;
* the password is correct;
* the database host is reachable from the web server;
* PHP has the MariaDB/MySQL extension installed.

## Resume indexing and document parsing

OpenCATS can use external tools to extract text from uploaded resumes and documents. The installer may ask for paths to these tools. Typical Linux paths are:

```
/usr/bin/antiword
/usr/bin/pdftotext
/usr/bin/html2text
/usr/bin/unrtf
```

OpenCATS can be installed without these tools. Resume indexing and text extraction will be limited until you install the utilities and configure the paths in `config.php`.

## Mail settings

OpenCATS can send mail through PHP mail, Sendmail, or SMTP. If you do not want OpenCATS to send email immediately, disable mail during installation and configure it later.

For SMTP, collect these values before enabling mail:

* SMTP host
* SMTP port
* authentication username
* authentication password or app password
* security mode such as `tls` or `ssl`

OpenCATS uses PHPMailer for email delivery.

## Installation type

The installer may offer options such as:

* new installation;
* demo/test data installation;
* restore from backup;
* use an existing OpenCATS database and perform required upgrades.

For production upgrades, use the existing installation/upgrade path only after taking CLI backups and testing the upgrade on a copy of production data.

## First login

For a new installation, the default login is commonly:

```
admin / admin
```

Change the administrator password immediately after logging in.

## Post-install checklist

After clicking `Start OpenCATS` and logging in:

* Change the default administrator password.
* Confirm `INSTALL_BLOCK` exists.
* Confirm `attachments/`, `upload/`, and `temp/` permissions are no broader than necessary.
* Configure upload-directory execution restrictions before exposing the career portal or accepting uploads.
* Configure mail and scheduled reminders if needed.
* Take an initial CLI database and attachments backup.

If you are exposing OpenCATS to the web, review [Security](/technical-configuration-options/security.md) and [Vital Security: Restrict access to upload folders (.htaccess)](/technical-configuration-options/vital-security-restrict-access-to-upload-folders-.htaccess.md).