micro run - Local Development - Go Micro

micro run provides a complete development environment for Go microservices.

Note: This guide focuses on micro run features. For a comparison with micro server and gateway architecture details, see the CLI & Gateway Guide.

micro run is a development tool. It builds and supervises your service processes locally with hot reload. There is no daemon — everything stops when micro run exits. For running services in production, see Going to production.

Quick Start

bash

micro new helloworld
cd helloworld
micro run

Open http://localhost:8080 to see your service.

What You Get

When you run micro run, you get:

URL	Description
http://localhost:8080	Web dashboard - browse and call services
http://localhost:8080/agent	Agent playground - AI chat with MCP tools
http://localhost:8080/api	API explorer - browse endpoints and schemas
http://localhost:8080/api/{service}/{method}	API gateway - HTTP to RPC proxy
http://localhost:8080/mcp/tools	MCP tools - list all services as AI tools
http://localhost:8080/auth/tokens	Token management - create and manage API tokens
http://localhost:8080/auth/scopes	Scope management - restrict endpoint access
http://localhost:8080/auth/users	User management - create and manage users
http://localhost:8080/health	Health checks - aggregated service health
http://localhost:8080/services	Service list - JSON

Plus:

Authentication - off on loopback (the dev default), automatically on when the gateway is bound to a non-loopback address — using a token printed once at startup, never a default credential
Hot Reload - File changes trigger automatic rebuild
Dependency Ordering - Services start in the right order
Environment Management - Dev/staging/production configs
MCP Gateway - Optional dedicated MCP protocol listener via --mcp-address

Features

API Gateway

The gateway converts HTTP requests to RPC calls. On loopback (the micro run default) no auth is needed — just call it:

bash

curl -X POST http://localhost:8080/api/helloworld/Say.Hello \
  -d '{"name": "World"}'

# Response
{"message": "Hello World"}

See Authentication for when a token is required.

Authentication

Auth follows the socket, not the command. The bind address decides the default:

Loopback (127.0.0.1/localhost, the micro run default) → auth off. You're already behind the OS boundary, so there's no login to call your own tools.
Non-loopback (0.0.0.0 or a routable IP) → auth on automatically. The instant it's reachable by others it's protected.

When auth is on there is no default credential. A machine token is printed once at startup (or supply your own with --auth-token / MICRO_AUTH_TOKEN), and every /api and /mcp call carries it:

bash

curl -H "Authorization: Bearer <token>" http://HOST:8080/api/helloworld/Say.Hello -d '{"name":"World"}'
# SSE / browser links can use ?token=<token> instead

Override the default either way with --auth / --no-auth (or MICRO_AUTH=on|off).

Capability-aware, even locally: a tool that declares a required scope — actions, paid tools — always needs a token bearing that scope, even on a loopback gateway with auth off. Read-only tools stay open; dangerous ones don't. Manage per-endpoint scopes at /auth/scopes.

Agent Playground

The agent playground at /agent lets you interact with your services using AI. Your services are automatically exposed as MCP (Model Context Protocol) tools — no configuration needed.

Open http://localhost:8080/agent
Configure your API key in Agent Settings (supports OpenAI and Anthropic)
Chat with the AI agent — it can discover and call your services as tools

The MCP tools API is available at:

/mcp/tools — list all services as AI-callable tools
/mcp/call — invoke a tool (service endpoint) by name

For a dedicated MCP protocol listener (for external AI clients), use:

bash

micro run --mcp-address :3000

Hot Reload

By default, micro run watches for .go file changes and automatically rebuilds and restarts affected services.

bash

micro run              # Hot reload enabled (default)
micro run --no-watch   # Disable hot reload

Changes are debounced (300ms) to handle rapid saves from editors.

Configuration File

For multi-service projects, create a micro.mu file to define services, dependencies, and environments.

micro.mu (Recommended)

# Service definitions
service users
    path ./users
    port 8081

service posts
    path ./posts
    port 8082
    depends users

service web
    path ./web
    port 8089
    depends users posts

# Environment configurations
env development
    STORE_ADDRESS file://./data
    DEBUG true

env production
    STORE_ADDRESS postgres://localhost/db
    DEBUG false

micro.json (Alternative)

json

{
  "services": {
    "users": {
      "path": "./users",
      "port": 8081
    },
    "posts": {
      "path": "./posts",
      "port": 8082,
      "depends": ["users"]
    }
  },
  "env": {
    "development": {
      "STORE_ADDRESS": "file://./data"
    }
  }
}

Service Properties

Property	Required	Description
`path`	Yes	Directory containing the service (with main.go)
`port`	No	Port the service listens on (enables health check waiting)
`depends`	No	Services that must start first (space-separated in .mu, array in .json)

Dependency Ordering

When depends is specified, services start in topological order:

Services with no dependencies start first
Each service waits for its dependencies to be ready
If a service has a port, we wait for /health to return 200
Circular dependencies are detected and reported as errors

Environment Management

bash

micro run                    # Uses 'development' (default)
micro run --env production   # Uses 'production'
micro run --env staging      # Uses 'staging'
MICRO_ENV=test micro run     # Environment variable override

Environment variables from the config are injected into each service's environment.

Graceful Shutdown

On SIGINT (Ctrl+C) or SIGTERM:

Services stop in reverse dependency order
SIGTERM is sent first (graceful)
After 5 seconds, SIGKILL if still running
PID files are cleaned up

Without Configuration

If no micro.mu or micro.json exists:

All main.go files are discovered recursively
Each is built and run
No dependency ordering
Hot reload still works

Logs

Every service streams to the terminal running micro run, colorized and prefixed with the service name. The same output is also written to a file:

bash

tail -f ~/micro/logs/users-*.log   # one file per service: {service}-{hash}.log

Lifecycle

micro run is itself the process manager for as long as it runs — there is no daemon and no micro status/micro stop command. Stop everything with Ctrl-C; services are shut down in reverse dependency order.

On a .go change a service is rebuilt in place. If the rebuild fails to compile, the previous version keeps running and the build error is printed — a typo never takes your service offline. New service directories added while micro run is up (e.g. by micro new or micro chat) are picked up and started automatically.

Example: a multi-service app

A multi-service app is described with a micro.mu file:

# micro.mu
service users
    path ./users
    port 8081

service posts
    path ./posts
    port 8082
    depends users

service comments
    path ./comments
    port 8083
    depends users posts

service web
    path ./web
    port 8089
    depends users posts comments

Run it — from the local directory, or straight from a repo:

bash

micro run .                       # current directory
micro run github.com/myorg/blog   # remote repo

Options

bash

micro run                        # Gateway on :8080, hot reload
micro run --address :3000        # Custom gateway port
micro run --no-gateway           # Services only, no HTTP gateway
micro run --no-watch             # Disable hot reload
micro run --env production       # Use production environment
micro run --mcp-address :3000    # Enable MCP protocol gateway for AI clients

Going to production

micro run has no production mode by design — it's the dev inner loop. In development it also hands you a gateway for free (--no-gateway to skip); in production you don't run micro run at all. To ship:

Build each service: go build produces a static binary.
Run it under a process manager or scheduler — systemd, Docker/Compose, or Kubernetes (see the Kubernetes deploy assets). That is your daemon: restarts, log capture, and boot persistence come from there, not from Go Micro.
Point them at a shared registry (Consul, etcd, or NATS) so they discover each other.
Front them with the gateway — the API/MCP gateway that turns your services into an HTTP API and AI-callable MCP tools, with a dashboard and auth (see the MCP gateway deploy assets).

Tips

Browse First: Open http://localhost:8080 to explore your services
Try the Agent: Open http://localhost:8080/agent to chat with your services via AI
Port Configuration: Set port for services to enable health check waiting
Health Endpoint: Implement /health returning 200 for reliable startup sequencing
Environment Separation: Keep secrets in production env, use file:// paths for development
Hot Reload Scope: Only .go files trigger rebuilds; static assets don't