Outport — Dev Port Manager

Outport allocates deterministic, non-conflicting ports for dev services, assigns .test hostnames, and writes everything to .env files. Every framework reads .env — Rails, Nuxt, Django, Docker Compose — so ports and URLs just work without manual configuration.

Quick Reference

# Project commands
outport init              # Create outport.yml (interactive)
outport up                # Allocate ports, assign hostnames, write .env
outport up --force        # Clear and re-allocate all ports from scratch
outport down              # Remove ports and clean .env files

# Inspect & diagnose
outport status            # Show project status (ports, health, URLs)
outport status --computed # Include computed values
outport ports             # Show ports with live process info (PID, memory, uptime)
outport ports --all       # Full machine scan (Outport + non-Outport ports)
outport ports --down      # Include ports with no running process
outport ports kill <svc>  # Kill process by service name or port number
outport ports kill --orphans  # Kill all orphaned dev processes
outport open              # Open HTTP services in browser
outport open web          # Open a specific service
outport share             # Tunnel HTTP services to public URLs
outport share web         # Tunnel a specific service
outport qr                # Show QR codes for mobile device access
outport qr --tunnel       # Show QR codes with tunnel URLs
outport doctor            # Check system health and project config

# System commands (machine-wide)
outport system start      # Install DNS, CA, and start the daemon
outport system stop       # Stop the daemon
outport system restart    # Re-write plist and restart the daemon
outport system status     # Show all registered projects
outport system status --check  # Show with health checks (up/down)
outport system prune      # Remove stale registry entries
outport system uninstall  # Remove DNS resolver, daemon, and CA

# Instance management
outport rename <old> <new>  # Rename the current instance
outport promote             # Promote the current instance to main

All commands support --json for machine-readable output.

Setting Up a New Project

1. Create outport.yml

Run outport init for interactive setup, or create manually:

name: my-project
services:
  web:
    env_var: PORT
  postgres:
    env_var: DB_PORT
  redis:
    env_var: REDIS_PORT

2. Run outport up

Allocates deterministic ports (hashed from project name + service name) and writes them to .env. Same inputs always produce the same ports.

3. Wire up your project to read from .env

Most frameworks read .env natively or with minimal setup:

• Docker Compose — reads .env automatically. Use ${DB_PORT:-5432} in compose.yml
• Rails — use dotenv-rails gem, or reference env vars in config: port: ENV.fetch("DB_PORT", 5432)
• Nuxt — reads .env natively. Runtime config values can be overridden via NUXT_* env vars
• Foreman — reads .env automatically
• Overmind — does NOT auto-load .env. Source it in your start script:

  if [ -f .env ]; then set -a; source .env; set +a; fi
  

4. Commit outport.yml, gitignore .env

outport.yml is project config — commit it so worktrees and teammates inherit it. .env contains allocated ports — gitignore it. Each checkout gets its own.

.test Domains (DNS Proxying)

Running outport system start once enables friendly .test hostnames for your services. After setup, https://myapp.test routes to your app instead of http://localhost:24920.

How it works

outport system start installs three components (requires sudo for DNS and CA trust):

1. DNS resolver — configures your OS to send *.test queries to a local DNS server on port 15353, which resolves all *.test names to 127.0.0.1. On macOS this is /etc/resolver/test; on Linux it's a systemd-resolved drop-in config.
2. Reverse proxy — a daemon runs on ports 80 and 443, routes requests by Host header to the correct service port, and auto-updates when you run outport up. WebSocket connections are proxied transparently. Managed by launchd on macOS, systemd on Linux.
3. Local CA — generates a Certificate Authority for HTTPS. HTTP requests on port 80 are redirected to HTTPS via 307.

outport system start      # Install DNS + CA + daemon (one-time, prompts for sudo)
outport system stop       # Stop the daemon
outport system restart    # Re-write plist and restart the daemon
outport system uninstall  # Remove everything — reverse of start

Configuring .test hostnames

Add hostname to a service to assign it a .test URL:

name: myapp
services:
  web:
    env_var: PORT
    hostname: myapp.test       # → https://myapp.test
  postgres:
    env_var: DB_PORT           # no hostname: port allocation only

Hostname rules:

• Must include the project name (e.g., myapp.test, app.myapp.test)
• Non-main instances get the instance code appended automatically (see Multiple Instances)

Cookie isolation

Each instance gets its own .test hostname, so browser cookies and sessions are isolated automatically — no incognito windows needed:

myapp [main]   web → 24920   http://myapp.test
myapp [bkrm]   web → 28104   http://myapp-bkrm.test

Config Reference

Project-Level Fields

Field	Required	Description
name	yes	Project identifier. Used for port allocation and hostname generation.
open	no	List of service names that outport open opens by default. When omitted, opens all services with a hostname.

Service Fields

Field	Required	Description
env_var	yes	Environment variable name written to .env
hostname	no	.test hostname for this service (e.g., myapp.test). Implies HTTP. Non-main instances get the instance code appended.
aliases	no	Named alternative hostnames (map of label → hostname). Each alias routes to the same port. Requires hostname.
preferred_port	no	Port to try first. Falls back to hash-based allocation if already in use
env_file	no	Where to write. String or array. Defaults to .env in project root

Writing to Multiple .env Files

For monorepos, a port often needs to appear in multiple .env files. Use an array for env_file:

services:
  rails:
    env_var: RAILS_PORT
    env_file:
      - backend/.env
      - frontend/.env          # Frontend needs this to construct API URLs

Computed Values

Applications don't just need port numbers — they need URLs. Computed values compute environment variables from your service map and write finished values to .env.

Basic syntax

computed:
  API_URL:
    value: "${rails.url:direct}/api/v1"   # http://localhost:24920/api/v1
    env_file: frontend/.env
  CORS_ORIGINS:
    value: "${web.url}"                   # http://myapp.test (or localhost:PORT)
    env_file: backend/.env

• ${service_name.field} references service fields
• env_file is required (no default — you must be explicit)
• Computed names must not collide with service env_var names

Template Fields

Template	Resolves to	Use case
${rails.port}	24920	Raw port number
${rails.hostname}	myapp.test (or localhost if no hostname set)	Hostname only
${rails.url}	http://myapp.test	Browser-facing URLs (CORS, asset hosts), routed via proxy
${rails.url:direct}	http://localhost:24920	Server-to-server calls that bypass the proxy
${rails.env_var}	PORT	Env var name for the service
${rails.alias.NAME}	app.myapp.test	Alias hostname by label
${rails.alias_url.NAME}	https://app.myapp.test	Alias URL by label

When to use url vs url:direct:

• ${service.url} — for values the browser sends (CORS origins, asset hosts, OAuth redirect URIs). Uses the .test hostname when configured.
• ${service.url:direct} — for server-to-server calls (API base URLs a backend fetches, WebSocket connections from a Node server). Always uses localhost — no proxy hop.

Standalone variables and bash-style parameter expansion

Computed values support standalone variables and bash-style parameter expansion for instance-aware configuration:

Variable	Main instance	Worktree instance (e.g., bxcf)
${project_name}	myapp	myapp
${instance}	(empty string)	bxcf
${instance:-default}	default	bxcf
${instance:+replacement}	(empty string)	replacement
${instance:+-${instance}}	(empty string)	-bxcf

Common pattern — Docker Compose project name:

computed:
  COMPOSE_PROJECT_NAME:
    value: "${project_name}${instance:+-${instance}}"
    env_file: .env

This produces myapp for the main instance and myapp-bxcf for worktrees, giving each instance isolated Docker containers.

Per-file value overrides

When the same env var needs different values in different files (common in monorepos where multiple apps share a framework convention), use the object syntax for env_file entries:

computed:
  NUXT_API_BASE_URL:
    env_file:
      - file: frontend/apps/main/.env
        value: "${rails.url:direct}/api/v1"
      - file: frontend/apps/portal/.env
        value: "${rails.url:direct}/portal/api/v1"

You can mix plain string entries (which use the top-level value) with object entries in the same list.

Real-world monorepo example

Rails backend with two Nuxt frontends. Backend needs CORS origins from frontend .test URLs. Frontends need the Rails API URL for server-side fetches:

name: myapp
services:
  rails:
    env_var: RAILS_PORT
    hostname: myapp.test
    env_file: backend/.env
  frontend_main:
    env_var: MAIN_PORT
    hostname: app.myapp.test
    env_file:
      - frontend/apps/main/.env
      - backend/.env               # Backend needs this for CORS
  frontend_portal:
    env_var: PORTAL_PORT
    hostname: portal.myapp.test
    env_file:
      - frontend/apps/portal/.env
      - backend/.env               # Backend needs this for CORS

computed:
  # Server-to-server API URLs (bypass proxy — use direct localhost)
  NUXT_API_BASE_URL:
    env_file:
      - file: frontend/apps/main/.env
        value: "${rails.url:direct}/api/v1"
      - file: frontend/apps/portal/.env
        value: "${rails.url:direct}/portal/api/v1"

  # Backend CORS (browser-facing — use .test hostnames)
  CORE_CORS_ORIGINS:
    value: "${frontend_main.url},${frontend_portal.url}"
    env_file: backend/.env

  # Backend asset host (browser-facing)
  SHRINE_ASSET_HOST:
    value: "${rails.url}"
    env_file: backend/.env

After outport up, every service has the right ports AND the right URLs. No hardcoded values survive.

Framework Env Var Conventions

When setting up computed values, knowing how frameworks map env vars to config is essential:

Framework	Convention	Example
Nuxt	NUXT_ prefix maps to runtimeConfig	NUXT_API_BASE_URL overrides runtimeConfig.apiBaseUrl
Rails (AnyWayConfig)	PREFIX_ATTR maps to config class	CORE_CORS_ORIGINS overrides CoreConfig.cors_origins
Rails (Shrine)	Same AnyWayConfig pattern	SHRINE_ASSET_HOST overrides ShrineConfig.asset_host
Django	Typically reads os.environ directly	Name vars however your settings.py expects
Docker Compose	Reads .env automatically	${DB_PORT:-5432} in compose.yml

The computed values feature is most powerful when it writes env vars that match these framework conventions — the framework reads the value natively and no config code changes are needed.

.env File Format

Outport writes managed variables in a fenced block at the bottom of each .env file:

# Your own variables — Outport never touches these
SECRET_KEY=abc123
RAILS_ENV=development

# --- begin outport.dev ---
DB_PORT=21536
RAILS_PORT=24920
NUXT_API_BASE_URL=http://localhost:24920/api/v1
# --- end outport.dev ---

On each outport up, the fenced block is replaced with current values. Variables removed from outport.yml disappear from the block. Everything outside the block is preserved.

Multiple Instances

Outport detects git worktrees automatically. Each worktree gets unique ports and its own .test hostname — no configuration needed:

# Main checkout
$ outport up
my-app [main]
  rails  RAILS_PORT → 24920  http://my-app.test
  web    MAIN_PORT  → 21349

# Worktree — different ports, different hostname, zero conflicts
$ cd ../my-app-feature && outport up
  Registered as my-app-bkrm. Use 'outport rename bkrm <name>' to rename.
my-app [bkrm]
  rails  RAILS_PORT → 20192  http://my-app-bkrm.test
  web    MAIN_PORT  → 21133

Computed values are recomputed per instance — CORS origins, API URLs, and all other computed values automatically use that instance's ports and hostnames. Two full instances run simultaneously with no port collisions, no hostname collisions, and no manual configuration.

Manage instances with:

outport rename bkrm my-feature   # Rename an instance
outport promote                   # Promote current instance to main

Integrating with Setup Scripts

Run outport up early in your project's setup flow — after .env file creation but before services start. Make it optional so developers without Outport aren't blocked:

# In bin/setup or similar
if command -v outport > /dev/null 2>&1; then
  outport up
else
  echo "Outport not found — using default ports"
  echo "Install: brew install steveclarke/tap/outport"
fi

Common Tasks

Port conflict with another project

Run outport up in both projects. Outport's registry ensures no collisions across all registered projects.

Ports are stale from an old allocation

Run outport up --force to clear and re-allocate.

Freeing ports from a project you're done with

Run outport down to remove from registry and free all ports.

Adding a new service to an existing project

Add it to outport.yml and run outport up. Existing allocations are preserved — only the new service gets a port.

Agent needs to know the project's URLs

Run outport status --json for structured output with ports, health, and URLs.

Services moved to different ports than expected

Check outport system status to see all allocations. If another project holds the ports you want, run outport down in it first, then outport up --force in yours.

Accessing dev services from a phone

Run outport qr to display a QR code encoding the LAN URL for each HTTP service. Scan with your phone on the same Wi-Fi to open the app. Use outport qr --tunnel while outport share is running to get a QR for the public tunnel URL instead. QR codes are also available in the dashboard at outport.test.

Sharing a service with someone outside your network

Run outport share to tunnel all HTTP services to public Cloudflare URLs. Requires cloudflared (brew install cloudflared). Press Ctrl+C to stop.

Something isn't working

Run outport doctor to check DNS, daemon, certificates, registry, and project config. Each check shows pass/fail with a fix suggestion.

.test domain not resolving

Run outport doctor to diagnose. Common causes: daemon not running (outport system start) or DNS resolver missing (outport system start).

Bugs & Feature Requests

Report bugs or request new features at https://github.com/steveclarke/outport/issues