fly-cli

name	fly-cli
description	Use the Fly.io CLI (flyctl) to deploy applications to edge locations, manage machines, volumes, secrets, and databases.

Fly.io CLI (flyctl / fly)

Official CLI for Fly.io. Deploy apps globally to edge locations with Firecracker VMs.

• Official repo: https://github.com/superfly/flyctl
• Docs: https://fly.io/docs/flyctl/

Authentication

fly auth login                            # Browser-based login
fly auth token                            # Print auth token
fly auth whoami                           # Check current user

Common Commands

Apps

fly launch                                # Create and configure new app
fly deploy                                # Deploy current directory
fly deploy --image my-registry/my-app:v1  # Deploy specific image
fly apps list
fly status                                # Current app status
fly open                                  # Open app in browser

Machines

fly machine list
fly machine start MACHINE_ID
fly machine stop MACHINE_ID
fly machine restart MACHINE_ID
fly machine status MACHINE_ID

Scaling

fly scale count 3                         # Set instance count
fly scale vm shared-cpu-1x                # Change VM size
fly scale memory 512                      # Set memory (MB)
fly scale show                            # Show current scale
fly regions add ord                       # Add region
fly regions list                          # List regions

Secrets

fly secrets set DATABASE_URL=postgres://...
fly secrets list
fly secrets unset DATABASE_URL

Logs and SSH

fly logs                                  # Stream logs
fly ssh console                           # SSH into running machine
fly ssh console -C "ls /app"              # Run command via SSH

Databases

fly postgres create                       # Create managed Postgres
fly postgres list
fly postgres connect -a my-db             # Connect to Postgres

Volumes

fly volumes create my_data --size 10      # Create 10GB volume
fly volumes list

Agent Best Practices

• Use fly status to check app health and deployment status
• Use fly deploy --strategy rolling for zero-downtime deploys
• Use fly logs to debug issues after deployment
• Set secrets before deploying: fly secrets set triggers a redeploy
• Use fly ssh console -C "command" for one-off remote commands
• Use fly scale count to manage instance count per region

Example Workflows

Deploy and verify

fly deploy
fly status
fly logs --instance INSTANCE_ID

Scale to multiple regions

fly regions add lax ord ams
fly scale count 2