Fly.io Install & Auth

Overview

Install flyctl CLI and configure authentication for Fly.io edge compute platform. Two auth methods: interactive login (opens browser) and API tokens (CI/CD and Machines API). The Machines API base URL is https://api.machines.dev.

Prerequisites

Fly.io account at fly.io
macOS, Linux, or WSL2

Instructions

Step 1: Install flyctl

# macOS / Linux
curl -L https://fly.io/install.sh | sh

# Or via Homebrew
brew install flyctl

# Verify
fly version

Step 2: Authenticate

# Interactive login (opens browser)
fly auth login

# Or with token (CI/CD)
fly auth token  # Get current token
export FLY_API_TOKEN="fo1_your_token_here"

# Verify auth
fly auth whoami

Step 3: Create API Token for Machines API

# Create deploy token (scoped to an app)
fly tokens create deploy -a my-app

# Create org-level token
fly tokens create org

# Use with Machines API
curl -s -H "Authorization: Bearer $FLY_API_TOKEN" \
  https://api.machines.dev/v1/apps | jq '.[].name'

Step 4: Verify Machines API Access

const FLY_API = 'https://api.machines.dev';

async function verifyFlyAccess() {
  const res = await fetch(`${FLY_API}/v1/apps`, {
    headers: { 'Authorization': `Bearer ${process.env.FLY_API_TOKEN}` },
  });
  const apps = await res.json();
  console.log(`Connected. Found ${apps.length} apps.`);
  apps.forEach((app: any) => console.log(`  ${app.name} (${app.organization.slug})`));
}

Token Types

Token Type	Scope	Lifetime	Use Case
User token	All orgs/apps	Until revoked	Development, personal
Deploy token	Single app	Until revoked	CI/CD per app
Org token	All apps in org	Until revoked	Org-wide automation
Machines token	API access	Until revoked	Machines API calls

Error Handling

Error	Cause	Solution
`Error: not authenticated`	No token set	Run `fly auth login` or set `FLY_API_TOKEN`
`401 Unauthorized`	Invalid/expired token	Regenerate with `fly tokens create`
`Could not find app`	Wrong app name	Check with `fly apps list`
`flyctl not found`	CLI not installed	Run install script above

Resources

Next Steps

After auth, proceed to flyio-hello-world for your first deployment.