Microservices Controller API

NestJS base controller factory for implementing CRUD microservices with message-based patterns.

What It Does

The Microservices Controller API provides a factory function that generates fully-functional CRUD controllers for NestJS microservices. It serves as the counterpart to the MicroserviceClient, abstracting away boilerplate code for exposing business logic through message-based communication with built-in validation, error handling, and distributed coordination.

Key Capabilities

Capability	Description
Factory-Generated Controllers	Create complete CRUD controllers with one function call
Message Pattern Routing	Automatic routing for 7 CRUD operations
Input Validation	Built-in class-validator integration with custom error formatting
Distributed Task Claiming	Redis-based locking prevents duplicate processing
Error Handling	Standardized RPC exception filtering and logging
Repository Integration	Works with Firestore collections and subcollections
Type Safety	Full TypeScript support with generic types
Automatic Timestamps	Response timestamps for created/modified fields

Configuration

Message Patterns

Follows MicroservicePaths convention
Collection-scoped routing
CRUD operation mapping

Validation

Enabled by default
class-validator integration
Custom error formatting

Task Claiming

Redis-based locking
30-second timeout
Automatic coordination

Exports

Factory Functions

MicroserviceController() - Controller factory

Models

Request classes (GetRequest, CreateRequest, etc.)
Response interfaces (from microservices-client)

Interceptors

ClaimTaskInterceptor - Task claiming

Pipes

MicroserviceValidationPipe - Validation pipe

Filters

E11RpcExceptionFilter - Error handling

Constants

API_NAME - ‘microservices’
MICROSERVICE_ERRORS - Error types

Common Use Cases

CRUD microservices: Implement full CRUD with one line of code
Multi-instance deployments: Safe distributed processing with task claiming
Message-based architecture: Expose business logic via message patterns
Type-safe services: Compile-time validation across service boundaries
Validated operations: Automatic request validation with clear errors
Hierarchical resources: Parent-child resource relationships

What Customers Don’t Have to Build

CRUD controller boilerplate
Message pattern decorators
Input validation pipes
Error handling filters
Distributed task claiming with Redis
Repository integration logic
Request/response type definitions
Timestamp metadata handling
RPC exception conversion
Validation error formatting
Observable response wrapping
Collection and subcollection support