EspoCRM Development Overview
EspoCRM is a metadata-driven CRM platform where configuration lives in JSON files, business logic belongs in Services, and data access happens through ORM EntityManager. This skill enforces architectural patterns to prevent common mistakes like passing Container dependencies, bypassing the service layer, or implementing business logic in hooks.
When to Use This Skill
Activate when developing custom EspoCRM modules, entities, relationships, hooks, services, API endpoints, or integrations. Use especially when: working with ORM (EntityManager required), implementing business logic (belongs in Services), creating hooks (use interfaces), modifying metadata (requires cache rebuild), building custom field types, creating complex queries with SelectBuilder, implementing custom API actions, or packaging extensions.
The Iron Law
BUSINESS LOGIC IN SERVICES, NOT HOOKS | DATA ACCESS VIA ENTITYMANAGER, NEVER DIRECT PDO | NEVER PASS CONTAINER AS DEPENDENCY
Accessing Container directly or writing business logic in hooks violates architecture.
Core Architecture Principles Metadata-Driven: Entity definitions, layouts, field configs live in JSON Service Layer: All business logic implemented in Service classes ORM EntityManager: Central access point for all database operations Dependency Injection: Constructor injection, never pass Container Hook System: Lifecycle events for validation and side effects (not business logic) Repository Pattern: Entities accessed through repositories Quick Start
Setup Development Environment - Use ext-template, work in src/ directory (EspoCRM 7.4+), understand metadata structure: custom/Espo/Modules/{ModuleName}/Resources/metadata/
Access Data with EntityManager
use Espo\ORM\EntityManager;
public function __construct(private EntityManager $entityManager) {}
// Find entity $account = $this->entityManager->getEntityById('Account', $id);
// Query with conditions $collection = $this->entityManager ->getRDBRepository('Contact') ->where(['accountId' => $accountId]) ->find();
Implement Business Logic in Services
namespace Espo\Modules\MyModule\Services;
use Espo\Services\Record;
class MyEntity extends Record { public function customAction(string $id, object $data): object { // Business logic here $entity = $this->entityManager->getEntityById($this->entityType, $id); // ... process ... $this->entityManager->saveEntity($entity); return $entity; } }
Register Hooks for Lifecycle Events
namespace Espo\Modules\MyModule\Hooks\Account;
use Espo\ORM\Entity; use Espo\Core\Hook\Hook\BeforeSave;
class MyHook implements BeforeSave { public function beforeSave(Entity $entity, array $options): void { // Validation or side effects only if ($entity->isAttributeChanged('status')) { // React to changes } } }
Rebuild Cache After Changes
bin/command rebuild
Hook Types (Interfaces)
EspoCRM provides 7 hook types - ALWAYS use interfaces: BeforeSave (validation before save), AfterSave (side effects after save), BeforeRemove (validation before delete), AfterRemove (cleanup after delete), AfterRelate (relationship creation), AfterUnrelate (relationship removal), AfterMassRelate (bulk relationship operations).
Navigation Core Concepts Architecture: Metadata system, ORM, DI container, repository pattern, and core architectural patterns Development Workflow: Module creation, custom entities, fields, APIs, and extension development process Hooks and Services: Service layer implementation, hook types, dependency injection, and business logic patterns Advanced Topics SelectBuilder: Advanced querying with SelectBuilder - complex queries, joins, aggregations, and query optimization API Actions: Creating custom API endpoints - action handlers, request/response patterns, and authentication Custom Field Types: Building custom field types - backend, frontend, metadata, and integration UI and Integration Frontend Customization: View system, client-side development, and UI customization Common Tasks: Scheduled jobs, emails, PDFs, ACL, workflows, and integration patterns Extension Packages: Packaging and distributing extensions - manifest files, installation, and versioning Quality Assurance Testing and Debugging: Unit tests, debugging techniques, performance optimization, and common pitfalls Key Patterns
Correct Pattern:
✅ Service with injected dependencies ✅ EntityManager for data access ✅ Hooks using interfaces ✅ Type declarations on all methods ✅ Exceptions for error handling
Incorrect Patterns:
❌ Passing Container as dependency ❌ Direct PDO database access ❌ Business logic in hooks ❌ Hook base classes instead of interfaces ❌ Missing type declarations
Common Mistakes to Avoid Never pass Container - Inject specific dependencies instead Don't bypass EntityManager - Use ORM, not raw queries Business logic doesn't belong in hooks - Use Services Always rebuild cache - After metadata changes (bin/command rebuild) Use interfaces for hooks - Not base classes Type everything - PHP 7.4+ requires type declarations Throw exceptions - Don't return booleans for errors Integration with Other Skills systematic-debugging: Debug EspoCRM issues using logs and step debugging verification-before-completion: Always test with cache rebuild before claiming complete test-driven-development: Write unit tests for Services and hooks The Bottom Line
EspoCRM is metadata-driven with a service layer architecture.
Understand the metadata system. Use EntityManager for data. Implement business logic in Services. Use hooks for lifecycle events only. Rebuild cache after changes.
This is the EspoCRM way.