fly · Fly.io

Fly.io flyctl for AI Agents

Deploy and inspect Fly.io applications, Machines, logs, and releases.

Official toolOperational risk: R2R3docs-verified
Agent readiness
84/100
Evidence confidence
docs-verified
Documentation checked
2026-07-10
Independently tested version
Not independently tested

Install for an Agent

Choose an official installation path that matches the runtime. Pin a version for team or CI use, then record the version before the first task.

HomebrewRecommended
macos · linux
$ shell
brew install flyctl
Authentication and Minimum Permissions
Grant only the permissions the task needs. Pass credentials through environment variables or a platform secret store, never through prompts, repositories, or logs.
Authentication requiredHeadless authentication supported

Use a token scoped to the organization and app required by the task.

Methods
browser login, access token
Secret environment variables
FLY_API_TOKEN
Credential storage
For headless runs, inject FLY_API_TOKEN from the CI or platform secret manager at process start. For local interactive use, prefer the CLI or operating-system credential store when the official client supports one. Never save values in repository files.
Agent and Environment Compatibility
Confirm shell access first, then check the platform, network boundary, and credential path.
claude-codecodexgemini-clicopilot-cli
Environments
local, ci, container, headless, remote
Platforms
macos, linux, windows

Structured Output for Reliable Automation

Prefer a machine-readable format. Treat stdout as the result channel and stderr as diagnostics so the agent can parse failures separately.

json · text
Use --json where supported and keep diagnostic logs on stderr.
--json

No independently captured output sample

Structured-output support currently comes from official documentation. CLI Finder does not show a guessed example or invented schema before a bounded, non-destructive execution captures stdout.

R0–R3 Command Risk Guide

Risk is assigned per command. R0 is local or remote read-only, R1 is reversible local write, R2 changes remote state, and R3 can be irreversible or production-impacting.

Read-only does not mean public

R0 only means the command does not change local or remote state. A read-only command may still return secrets, identity data, configuration, or production data. Expose only the minimum needed for the task, and never place it in logs, prompts, or commits.

R0Inspect app status
Reads Machines and deployment state.
$ shell
fly status --app APP --json
IdempotentSensitive output
R2Deploy an app
Builds and releases application code remotely.
$ shell
fly deploy --app APP
Confirmation requiredMay repeat a change
R3Destroy an app
Deletes the remote application and attached state.
$ shell
fly apps destroy APP
Confirmation requiredMay repeat a change

How the Agent Readiness Score Is Built

Readiness describes how reliably an agent can operate the tool. It does not make every command safe and it does not replace an independent execution test.

Documentation indicates an agent-readiness score of 84/100. No local execution test has been recorded.

Structured output
Use --json where supported and keep diagnostic logs on stderr.
18/20
x
Headless operation
Official documentation describes a non-interactive authentication or execution path.
14/15
x
Safety controls
CLI Finder separates read commands from commands that require confirmation.
11/15
x
Determinism
Commands use explicit arguments and documented output controls where available.
8/10
x
Authentication
Use a token scoped to the organization and app required by the task.
8/10
x
Documentation
This entry cites official documentation checked on 2026-07-10.
9/10
x
Installation
Official installation paths cover macOS, Linux, and Windows.
8/8
x
Maintenance
An official source repository is linked for release and maintenance review.
6/7
x
Agent artifacts
CLI Finder can generate registry-derived skills and policies; the tool itself was not credited with shipping them.
2/5
x

Generate a Skill or Agent Policy

Choose an agent and safety mode to generate a copyable artifact with installation, allowed commands, approval boundaries, and the evidence limitation.

Generated artifact preview
SKILL.md
---
name: flyctl-agent-workflow
description: Use Fly.io flyctl for Fly.io apps, Machines, logs with explicit command risk and evidence boundaries.
---

# Fly.io flyctl agent workflow

Use this skill when the task needs Fly.io apps, Machines, logs, releases.

## Evidence boundary

- Registry confidence: `docs-verified`
- Documentation checked: `2026-07-10`
- Locally tested version: `not tested`
- Do not describe this CLI as locally verified until its commands have actually been executed in an isolated environment.

## Executed smoke checks

- No local execution record is available.

## Installation

- Homebrew (macos, linux): `brew install flyctl`

## Authentication

- Methods: browser login, access token
- Secret environment variables: `FLY_API_TOKEN`
- Minimum permissions: Use a token scoped to the organization and app required by the task.
- Credential storage: For headless runs, inject FLY_API_TOKEN from the CI or platform secret manager at process start. For local interactive use, prefer the CLI or operating-system credential store when the official client supports one. Never save values in repository files.
- Never print, persist, or commit credential values.

## Allowed commands (read-only)

- `fly status --app APP --json` — R0: Reads Machines and deployment state.

## Commands requiring explicit approval (read-only)

- None recorded.

## Forbidden commands (read-only)

- R2 `fly deploy --app APP` — Builds and releases application code remotely.
- R3 `fly apps destroy APP` — Deletes the remote application and attached state.

## Execution rules

1. Mode boundary: R0 exact commands may be used; R1, R2, and R3 commands are forbidden.
2. Confirm the selected account, project, context, database, namespace, or environment before any command.
3. Prefer structured output using `--json`.
4. Capture the exact command, exit code, stdout, and stderr separately.
5. A generated prefix policy must prompt unless that exact prefix is explicitly marked suffix-safe; do not infer safety from the executable name.
6. Never broaden credentials or disable safety controls to make a command succeed.

## Official sources

- [flyctl documentation](https://fly.io/docs/flyctl/)
- [flyctl documentation source repository](https://github.com/superfly/flyctl)

CLI vs MCP vs API for This Task

CLI
Use the CLI on a developer machine, in CI, or in a container when the task should reuse existing shell state, credentials, and scripts and remain directly observable.
MCP
Consider MCP when the agent benefits from controlled tool definitions, delegated identity, or centrally governed server-side access.
API
Use the direct API for persistent application integrations, high-volume requests, or event-driven work where starting a process adds unnecessary overhead.
Read the full CLI vs MCP guide

Verification History and Official Evidence

CLI Finder records documentation review separately from real execution. Installation, help, exit codes, and output cannot be called Verified until they were run.

Current evidence boundary
Official documentation was reviewed, but installation, help output, exit codes, headless behavior, and structured output were not executed locally.
Evidence confidence
docs-verified
Independently tested version
Not independently tested
Test environment
Not recorded
Official sources
Open the official material to confirm the current version and command behavior.

Alternatives and Related Paths

Deploy applications and inspect cloud resources with explicit environment boundaries.
Create, inspect, and promote Vercel deployments without relying on the dashboard.
Develop, deploy, and inspect Cloudflare Workers and related resources.
Validate configuration and build output, run a local or preview check, then deploy only to the named environment and verify it.
Pair Codex with deterministic local tools and add remote CLIs only when the sandbox and approval policy allow the task.
Choose CLI for shell-native local and CI work; choose MCP when typed discovery and mediated remote permissions matter more.

Questions About Fly.io flyctl for AI Agents