Bitrix Project Structure

Project structure and autoloading

Baseline: main 23.0+ · Verified: main 26.800.0

Roots

• /bitrix/ — kernel and marketplace modules; replaced by updates. Never edit (bitrix-framework).
• /local/ — all project code; same relative path in /local/ wins over /bitrix/.
• /upload/ — user/module files.

/local/
├── modules/<vendor>.<module>/   # project code lives in modules (bitrix-modules)
├── components/<ns>/<name>/      # bitrix-components
├── templates/<site_tpl>/        # site templates, component template overrides
├── routes/web.php               # bitrix-routing
├── js/<vendor>/<module>/<ext>/  # extension id vendor.module.ext (bitrix-extensions)
├── activities/                  # bizproc activities (also activities/custom)
├── gadgets/<ns>/<name>/         # desktop gadgets
├── blocks/                      # landing blocks repo
├── php_interface/
│   ├── init.php                 # every hit, before page code
│   ├── dbconn.php               # Since main 24.100 here; kernel constants
│   ├── after_connect_d7.php     # after the "default" DB connect only
│   └── user_lang/<lang>/lang.php # phrase overrides
├── .settings.php                # replaces /bitrix/.settings.php (bitrix-settings)
└── .settings_extra.php

Give /local/php_interface/ the same access protection as /bitrix/php_interface/.

php_interface files

• init.php: only constants needed before modules, and runtime addEventHandler() for hooks that belong to no module. Everything else → a module (install/, include.php, .settings.php).
• after_connect_d7.php is included inside the default connection object: use $this->queryExecute("SET …") (charset, sql_mode, time zone). Only one file runs — a /local copy disables the /bitrix one, so carry its statements over. Other connections run their own file via 'include_after_connected' => '/abs/path.php' in connections.

Loading a module (Loader)

Situation	Call
Module required; failure is a bug	Loader::requireModule('vendor.module') — throws LoaderException
Optional integration	if (Loader::includeModule('crm')) { … }
Shareware/demo status	Loader::includeSharewareModule()

includeModule() returns false if the module is not registered in b_module (files alone are not enough) or its include.php returns false. On success it registers the PSR-4 root, includes include.php, registers module services. Load once at the entry point (controller, agent, command), not deep in services. Legacy CModule::IncludeModule() — compat only.

PSR-4 in module lib/

• Root: vendor.module → Vendor\Module\ → lib/; one-word mymodule → Bitrix\Mymodule\.
• Folder = namespace segment, file = class: Vendor\Module\Public\Service\PostService → lib/Public/Service/PostService.php.
• Loader tries the exact-case path, then all-lowercase (kernel mixes both styles; since main 26.600 many kernel lib/ dirs are PascalCase). PostTable is also looked up as post.php.
• Never require kernel lib/ files by path — kernel updates rename them (e.g. lists 26.200 moved to PascalCase).
• Non-PSR-4 legacy code: Loader::registerNamespace('Vendor\\Legacy', $absDir) or Loader::registerAutoLoadClasses('vendor.module', ['COldClass' => 'classes/old.php']) in include.php.

Composer

• composer.json outside DOCUMENT_ROOT (e.g. project root), .settings.php → 'composer' => ['value' => ['config_path' => '../composer.json']]; the kernel includes its vendor/autoload.php.
• Required by bitrix.php (Symfony Console) — bitrix-console-commands.
• Never install packages into /bitrix/.

File priority

• Components, site templates, php_interface files, .settings*.php: /local/ first, then /bitrix/.
• Component templates: site template components/… overrides the component's own templates/.
• Modules: /local/modules/<id> wins when both exist.
• Module routes are not auto-loaded: require them from /local/routes/web.php (bitrix-routing).