# Nestjs Transport

> Configure gRPC, RabbitMQ, and monorepo contract patterns for NestJS microservices. Use when setting up gRPC service-to-service calls, RabbitMQ event-driven messaging, shared contract libraries, or microservice exception handling in NestJS.

- Skill: `filippodesilva/nestjs-transport` (Agent Skill, multi-file: 3 files)
- Install (CLI): `npx skillmds@latest add filippodesilva/nestjs-transport`
- Raw SKILL.md: https://api.skillmd.com/api/skills/filippodesilva/nestjs-transport/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- License: MIT
- Author: FilippoDeSilva (https://skillmd.com/u/filippodesilva)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/filippodesilva/nestjs-transport

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# Microservices & Transport Standards

## **Priority: P0 (FOUNDATIONAL)**


- **Synchronous (RPC)**: Use **gRPC** for low-latency, internal service-to-service calls (10x faster than REST/JSON).
- **Asynchronous (Events)**: Use **RabbitMQ** or **Kafka** for decoupling domains via fire-and-forget (`emit()`).

## gRPC Setup

See [implementation examples](references/example.md)

## RabbitMQ Setup

See [implementation examples](references/example.md)

## Monorepo Contracts

- Store all DTOs, `.proto` files, and Interfaces in `libs/contracts`.
- Services never import from sibling services — only from `contracts`.
- Semantic versioning of messages mandatory. Never change field type; add new field.

## Exception Handling

Standard `HttpException` lost over RPC/TCP. Use `RpcException` with global filters:

See [implementation examples](references/example.md)

## Serialization

- Apply `useGlobalPipes(new ValidationPipe({ transform: true }))` in `MicroserviceOptions` setup, not HTTP.

## Anti-Patterns

- **No cross-service imports**: Services must import only from `libs/contracts`, never from sibling services.
- **No HttpException in RPC**: Use `RpcException` with global `RpcExceptionFilter` for microservice errors.
- **No unversioned message schema**: Add new fields; never change existing field types — consumers will break.