> 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/technical-configuration-options/configuration-reference.md).

# Configuration Reference

Most OpenCATS runtime configuration is stored in `config.php`. This page summarizes commonly changed settings. Always back up `config.php` before editing it.

## Database settings

| Setting         | Purpose                                                                                      |
| --------------- | -------------------------------------------------------------------------------------------- |
| `DATABASE_USER` | MariaDB user OpenCATS uses to connect.                                                       |
| `DATABASE_PASS` | Password for `DATABASE_USER`.                                                                |
| `DATABASE_HOST` | Database host name. Use `localhost` for local installs or the Docker service name in Docker. |
| `DATABASE_NAME` | OpenCATS database name.                                                                      |

## Authentication settings

| Setting     | Purpose                                                                  |
| ----------- | ------------------------------------------------------------------------ |
| `AUTH_MODE` | Authentication mode. Supported values are `sql`, `ldap`, and `sql+ldap`. |

Use `sql` for normal OpenCATS-managed users. Use LDAP modes only after configuring the PHP LDAP extension and the LDAP connection settings required by your environment.

## Resume/document parser settings

| Setting           | Purpose                                                              |
| ----------------- | -------------------------------------------------------------------- |
| `PARSING_ENABLED` | Enables external resume parsing service integration when configured. |
| `ANTIWORD_PATH`   | Path to `antiword` for Word document text extraction.                |
| `ANTIWORD_MAP`    | Antiword character map.                                              |
| `PDFTOTEXT_PATH`  | Path to `pdftotext`.                                                 |
| `HTML2TEXT_PATH`  | Path to `html2text`.                                                 |
| `UNRTF_PATH`      | Path to `unrtf`.                                                     |

Parser utilities are optional for installation but useful for resume text extraction and search.

## Runtime paths

| Setting         | Purpose                                                  |
| --------------- | -------------------------------------------------------- |
| `CATS_TEMP_DIR` | Temporary directory writable by the web server.          |
| `MODULES_PATH`  | Path to OpenCATS modules. Usually does not need editing. |

## Sphinx search settings

| Setting         | Purpose                            |
| --------------- | ---------------------------------- |
| `ENABLE_SPHINX` | Enables Sphinx search integration. |
| `SPHINX_HOST`   | Sphinx host.                       |
| `SPHINX_PORT`   | Sphinx port.                       |
| `SPHINX_INDEX`  | Sphinx index names.                |

Leave Sphinx disabled unless you have installed and configured Sphinx.

## Session and display settings

| Setting                 | Purpose                                                                                     |
| ----------------------- | ------------------------------------------------------------------------------------------- |
| `CATS_SESSION_NAME`     | Session cookie name. Change only if hosting multiple OpenCATS instances on the same domain. |
| `ENABLE_SINGLE_SESSION` | Enforces one active session per user when enabled.                                          |
| `OFFSET_GMT`            | Legacy GMT offset setting.                                                                  |
| `HTML_ENCODING`         | HTML output encoding.                                                                       |
| `AJAX_ENCODING`         | AJAX output encoding.                                                                       |
| `SQL_CHARACTER_SET`     | SQL character set.                                                                          |

## Email settings

| Setting              | Purpose                                                          |
| -------------------- | ---------------------------------------------------------------- |
| `MAIL_MAILER`        | Mail method: `0` disabled, `1` PHP mail, `2` Sendmail, `3` SMTP. |
| `MAIL_SENDMAIL_PATH` | Sendmail binary path when using Sendmail.                        |
| `MAIL_SMTP_HOST`     | SMTP server host.                                                |
| `MAIL_SMTP_PORT`     | SMTP server port.                                                |
| `MAIL_SMTP_AUTH`     | Whether SMTP authentication is required.                         |
| `MAIL_SMTP_USER`     | SMTP username.                                                   |
| `MAIL_SMTP_PASS`     | SMTP password.                                                   |
| `MAIL_SMTP_SECURE`   | SMTP security mode: empty string, `ssl`, or `tls`.               |

Calendar reminder email text is also configurable in `config.php`.

## Career portal and SSL settings

| Setting                          | Purpose                                                         |
| -------------------------------- | --------------------------------------------------------------- |
| `SSL_ENABLED`                    | Enables SSL-aware behavior when your site is served over HTTPS. |
| `CAREERS_CANDIDATEAPPLY_SUBJECT` | Candidate email subject after career portal application.        |
| `CAREERS_OWNERAPPLY_SUBJECT`     | Owner email subject after career portal application.            |
| `CANDIDATE_STATUSCHANGE_SUBJECT` | Candidate email subject when status changes.                    |

## Demo and testing settings

| Setting              | Purpose                                                                    |
| -------------------- | -------------------------------------------------------------------------- |
| `ENABLE_DEMO_MODE`   | Enables demo mode behavior. Do not enable on normal production systems.    |
| `TESTER_*` constants | Automated testing defaults. Do not rely on these for production users.     |
| `DEMO_*` constants   | Demo login defaults. Do not expose demo credentials on production systems. |