micro

README

Go Micro

Go Micro is a framework for distributed systems development.

📖 Documentation | Sponsored by Anthropic

Overview

Go Micro provides the core requirements for distributed systems development including RPC and Event driven communication. The Go Micro philosophy is sane defaults with a pluggable architecture. We provide defaults to get you started quickly but everything can be easily swapped out.

Features

Go Micro abstracts away the details of distributed systems. Here are the main features.

• Authentication - Auth is built in as a first class citizen. Authentication and authorization enable secure zero trust networking by providing every service an identity and certificates. This additionally includes rule based access control.

• Dynamic Config - Load and hot reload dynamic config from anywhere. The config interface provides a way to load application level config from any source such as env vars, file, etcd. You can merge the sources and even define fallbacks.

• Data Storage - A simple data store interface to read, write and delete records. It includes support for many storage backends in the plugins repo. State and persistence becomes a core requirement beyond prototyping and Micro looks to build that into the framework.

• Data Model - A typed data model layer with CRUD operations, queries, and multiple backends (memory, SQLite, Postgres). Define Go structs with tags and get type-safe Create/Read/Update/Delete/List/Count operations. Accessible via service.Model() alongside service.Client() and service.Server() for a complete service experience: call services, handle requests, save and query data.

• Service Discovery - Automatic service registration and name resolution. Service discovery is at the core of micro service development. When service A needs to speak to service B it needs the location of that service. The default discovery mechanism is multicast DNS (mdns), a zeroconf system.

• Load Balancing - Client side load balancing built on service discovery. Once we have the addresses of any number of instances of a service we now need a way to decide which node to route to. We use random hashed load balancing to provide even distribution across the services and retry a different node if there's a problem.

• Message Encoding - Dynamic message encoding based on content-type. The client and server will use codecs along with content-type to seamlessly encode and decode Go types for you. Any variety of messages could be encoded and sent from different clients. The client and server handle this by default. This includes protobuf and json by default.

• RPC Client/Server - RPC based request/response with support for bidirectional streaming. We provide an abstraction for synchronous communication. A request made to a service will be automatically resolved, load balanced, dialled and streamed.

• Async Messaging - PubSub is built in as a first class citizen for asynchronous communication and event driven architectures. Event notifications are a core pattern in micro service development. The default messaging system is a HTTP event message broker.

• MCP Integration - An MCP gateway you can integrate as a library, server or CLI command which automatically exposes services as tools for agents or other AI applications. Every service/endpoint get's converted into a callable tool.

• Multi-Service Binaries - Run multiple services in a single process with isolated state per service. Start as a modular monolith, split into separate deployments when you need independent scaling. Each service gets its own server, client, and store while sharing the registry and broker for inter-service communication.

• Pluggable Interfaces - Go Micro makes use of Go interfaces for each distributed system abstraction. Because of this these interfaces are pluggable and allows Go Micro to be runtime agnostic. You can plugin any underlying technology.

Getting Started

To make use of Go Micro

go get go-micro.dev/v5@v5.16.0

Create a service and register a handler

package main

import (
        "go-micro.dev/v5"
)

type Request struct {
        Name string `json:"name"`
}

type Response struct {
        Message string `json:"message"`
}

type Say struct{}

func (h *Say) Hello(ctx context.Context, req *Request, rsp *Response) error {
        rsp.Message = "Hello " + req.Name
        return nil
}

func main() {
        // create the service
        service := micro.New("helloworld")

        // register handler
        service.Handle(new(Say))

        // run the service
        service.Run()
}

Set a fixed address

service := micro.New("helloworld", micro.Address(":8080"))

Call it via curl

curl -XPOST \
     -H 'Content-Type: application/json' \
     -H 'Micro-Endpoint: Say.Hello' \
     -d '{"name": "alice"}' \
      http://localhost:8080

MCP & AI Agents

Go Micro is designed for an agent-first workflow. Every service you build automatically becomes a tool that AI agents can discover and use via the Model Context Protocol (MCP).

• 🤖 Agent Playground — Chat with your services through an interactive AI agent at /agent
• 🔧 MCP Tools Registry — Browse all services exposed as AI-callable tools at /api/mcp/tools
• 📖 MCP Documentation — Full guide to MCP integration, auth, and scopes

Services as Tools

Write a normal Go Micro service and it's instantly available as an MCP tool:

// SayHello greets a person by name.
// @example {"name": "Alice"}
func (g *GreeterService) SayHello(ctx context.Context, req *HelloRequest, rsp *HelloResponse) error {
    rsp.Message = "Hello " + req.Name
    return nil
}

Run with micro run and the agent playground and MCP tools registry are ready:

micro run
# Agent Playground:  http://localhost:8080/agent
# MCP Tools:         http://localhost:8080/api/mcp/tools

Use micro mcp serve for local AI tools like Claude Code, or connect any MCP-compatible agent to the HTTP endpoint.

See the MCP guide for authentication, scopes, and advanced usage.

Multi-Service Binaries

Run multiple services in a single binary — start as a modular monolith, split into separate deployments later when you actually need to.

users := micro.New("users", micro.Address(":9001"))
orders := micro.New("orders", micro.Address(":9002"))

users.Handle(new(Users))
orders.Handle(new(Orders))

// Run all services together with shared lifecycle
g := micro.NewGroup(users, orders)
g.Run()

Each service gets its own server, client, store, and cache while sharing the registry, broker, and transport — so they can discover and call each other within the same process.

See the multi-service example for a working demo.

Data Model

Go Micro includes a typed data model layer for persistence. Define a struct, tag a key field, and get type-safe CRUD and query operations backed by memory, SQLite, or Postgres.

import (
        "go-micro.dev/v5/model"
        "go-micro.dev/v5/model/sqlite"
)

// Define your data type
type User struct {
        ID    string `json:"id" model:"key"`
        Name  string `json:"name"`
        Email string `json:"email" model:"index"`
        Age   int    `json:"age"`
}

Register your types and use the model:

service := micro.New("users")

// Register and use the service's model backend
db := service.Model()
db.Register(&User{})

// CRUD operations
db.Create(ctx, &User{ID: "1", Name: "Alice", Email: "alice@example.com", Age: 30})

user := &User{}
db.Read(ctx, "1", user)

user.Name = "Alice Smith"
db.Update(ctx, user)

db.Delete(ctx, "1", &User{})

Query with filters, ordering, and pagination:

var results []*User

// Find users by field
db.List(ctx, &results, model.Where("email", "alice@example.com"))

// Complex queries
db.List(ctx, &results,
        model.WhereOp("age", ">=", 18),
        model.OrderDesc("name"),
        model.Limit(10),
        model.Offset(20),
)

count, _ := users.Count(ctx, model.Where("age", 30))

Swap backends with an option:

// Development: in-memory (default)
service := micro.New("users")

// Production: SQLite or Postgres
db, _ := sqlite.New(model.WithDSN("file:app.db"))
service := micro.New("users", micro.Model(db))

Every service gets Client(), Server(), and Model() — call services, handle requests, and save data all from the same interface.

Examples

Check out /examples for runnable code:

• hello-world - Basic RPC service
• web-service - HTTP REST API
• multi-service - Multiple services in one binary
• mcp - MCP integration with AI agents

See all examples for more.

Protobuf

Install the code generator and see usage in the docs:

go install go-micro.dev/v5/cmd/protoc-gen-micro@v5.16.0

Note: Use a specific version instead of @latest to avoid module path conflicts. See releases for the latest version.

Docs: internal/website/docs/getting-started.md

Command Line

Install the CLI:

go install go-micro.dev/v5/cmd/micro@v5.16.0

Note: Use a specific version instead of @latest to avoid module path conflicts. See releases for the latest version.

Quick Start

micro new helloworld   # Create a new service
cd helloworld
micro run              # Run with API gateway and hot reload

Then open http://localhost:8080 to see your service and call it from the browser.

Development Workflow

Stage	Command	Purpose
Develop	micro run	Local dev with hot reload and API gateway
Build	micro build	Compile production binaries
Deploy	micro deploy	Push to a remote Linux server via SSH + systemd
Dashboard	micro server	Optional production web UI with JWT auth

micro run

micro run starts your services with:

• Web Dashboard - Browse and call services at /
• Agent Playground - AI chat with MCP tools at /agent
• API Explorer - Browse endpoints and schemas at /api
• API Gateway - HTTP to RPC proxy at /api/{service}/{method} (no auth in dev mode)
• MCP Tools - Services as AI tools at /api/mcp/tools
• Health Checks - Aggregated health at /health
• Hot Reload - Auto-rebuild on file changes

Note: micro run and micro server use a unified gateway architecture. See Gateway Architecture for details.

micro run                    # Gateway on :8080
micro run --address :3000    # Custom gateway port
micro run --no-gateway       # Services only
micro run --env production   # Use production environment

Configuration

For multi-service projects, create a micro.mu file:

service users
    path ./users
    port 8081

service posts
    path ./posts
    port 8082
    depends users

env development
    DATABASE_URL sqlite://./dev.db

The gateway runs on :8080 by default, so services should use other ports.

Deployment

Deploy to any Linux server with systemd:

# On your server (one-time setup)
curl -fsSL https://go-micro.dev/install.sh | sh
sudo micro init --server

# From your laptop
micro deploy user@your-server

The deploy command:

1. Builds binaries for Linux
2. Copies via SSH to the server
3. Sets up systemd services
4. Verifies services are healthy

Optionally run micro server on the deployed machine for a production web dashboard with JWT auth, user management, and API explorer.

Manage deployed services:

micro status --remote user@server    # Check status
micro logs --remote user@server      # View logs
micro logs myservice --remote user@server -f  # Follow specific service

No Docker required. No Kubernetes. Just systemd.

See internal/website/docs/deployment.md for full deployment guide.

See cmd/micro/README.md for full CLI documentation.

Docs: internal/website/docs

Package reference: https://pkg.go.dev/go-micro.dev/v5

User Guides:

• Getting Started
• Data Model
• MCP & AI Agents
• Plugins Overview
• Learn by Example
• Deployment Guide

Architecture & Performance:

• Performance Considerations
• Reflection Usage & Philosophy

Security:

• TLS Security Migration
• Security Migration Guide

Adopters

• Sourse - Work in the field of earth observation, including embedded Kubernetes running onboard aircraft, and we’ve built a mission management SaaS platform using Go Micro.

Documentation

Overview

Package micro is a pluggable framework for microservices

Index

• Variables
• func NewContext(ctx context.Context, s Service) context.Context
• func RegisterHandler(s server.Server, h interface{}, opts ...server.HandlerOption) error
• func RegisterSubscriber(topic string, s server.Server, h interface{}, opts ...server.SubscriberOption) error
• type Event
  • func NewEvent(topic string, c client.Client) Event
• type Group
  • func NewGroup(svcs ...Service) *Group
• type Option
• type Options
• type Publisher
• type Service
  • func FromContext(ctx context.Context) (Service, bool)
  • func New(name string, opts ...Option) Service
  • func NewService(opts ...Option) Service

Variables

var Action = service.Action

var AddListenOption = service.AddListenOption

var Address = service.Address

var AfterStart = service.AfterStart

var AfterStop = service.AfterStop

var Auth = service.Auth

var BeforeStart = service.BeforeStart

var BeforeStop = service.BeforeStop

var Broker = service.Broker

var Cache = service.Cache

var Client = service.Client

var Cmd = service.Cmd

var Config = service.Config

var Context = service.Context

var Flags = service.Flags

var Handle = service.Handle

var HandleSignal = service.HandleSignal

var Logger = service.Logger

var Metadata = service.Metadata

var Model = service.Model

var Name = service.Name

var Profile = service.Profile

var RegisterInterval = service.RegisterInterval

var RegisterTTL = service.RegisterTTL

var Registry = service.Registry

var Selector = service.Selector

var Server = service.Server

var Store = service.Store

var Tracer = service.Tracer

var Transport = service.Transport

var Version = service.Version

var WrapCall = service.WrapCall

var WrapClient = service.WrapClient

var WrapHandler = service.WrapHandler

var WrapSubscriber = service.WrapSubscriber

Functions

func NewContext

func NewContext(ctx context.Context, s Service) context.Context

NewContext returns a new Context with the Service embedded within it.

func RegisterHandler

func RegisterHandler(s server.Server, h interface{}, opts ...server.HandlerOption) error

RegisterHandler is syntactic sugar for registering a handler.

func RegisterSubscriber

func RegisterSubscriber(topic string, s server.Server, h interface{}, opts ...server.SubscriberOption) error

RegisterSubscriber is syntactic sugar for registering a subscriber.

Types

type Event

type Event interface {
	// Publish publishes a message to the event topic
	Publish(ctx context.Context, msg interface{}, opts ...client.PublishOption) error
}

Event is used to publish messages to a topic.

func NewEvent

func NewEvent(topic string, c client.Client) Event

NewEvent creates a new event publisher.

type Group

type Group = service.Group

Group is a set of services that share lifecycle management.

func NewGroup

func NewGroup(svcs ...Service) *Group

NewGroup creates a service group for running multiple services in a single binary with shared lifecycle management.

type Option

type Option = service.Option

type Options

type Options = service.Options

type Publisher

type Publisher = Event

Type alias to satisfy the deprecation.

type Service

type Service = service.Service

Service is the interface for a go-micro service.

func FromContext

func FromContext(ctx context.Context) (Service, bool)

FromContext retrieves a Service from the Context.

func New

func New(name string, opts ...Option) Service

New creates a new service with the given name and options.

service := micro.New("greeter")
service := micro.New("greeter", micro.Address(":8080"))

func NewService

func NewService(opts ...Option) Service

NewService creates and returns a new Service based on the packages within. Deprecated: Use New(name, opts...) instead.