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 mainAll 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_PORT2. 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
.envautomatically. Use${DB_PORT:-5432}incompose.yml - Rails — use
dotenv-railsgem, or reference env vars in config:port: ENV.fetch("DB_PORT", 5432) - Nuxt — reads
.envnatively. Runtime config values can be overridden viaNUXT_*env vars - Foreman — reads
.envautomatically - 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):
- DNS resolver — configures your OS to send
*.testqueries to a local DNS server on port 15353, which resolves all*.testnames to127.0.0.1. On macOS this is/etc/resolver/test; on Linux it's a systemd-resolved drop-in config. - Reverse proxy — a daemon runs on ports 80 and 443, routes requests by
Hostheader to the correct service port, and auto-updates when you runoutport up. WebSocket connections are proxied transparently. Managed by launchd on macOS, systemd on Linux. - 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 startConfiguring.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 onlyHostname 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.testConfig 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. |
subdomains | no | Enable wildcard subdomain routing (*.myapp.test). All subdomains route 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 URLsComputed 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 fieldsenv_fileis required (no default — you must be explicit)- Computed names must not collide with service
env_varnames
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:
${service.url}— for values the browser sends (CORS origins, asset hosts, OAuth redirect URIs). Uses the.testhostname when configured.${service.url:direct}— for server-to-server calls (API base URLs a backend fetches, WebSocket connections from a Node server). Always useslocalhost— 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:+-${instance}}"
env_file: .envThis produces myapp for the main instance and myapp-bxcf for worktrees, giving each instance isolated Docker containers.
Per-file value overrides
When the same env var needs different values in different files (common in monorepos where multiple apps share a framework convention), use the object syntax for env_file entries:
computed:
NUXT_API_BASE_URL:
env_file:
- file: frontend/apps/main/.env
value: "${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/.envAfter 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 → 21133Computed 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 mainIntegrating 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"
fiCommon 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