ngrok · ngrok

ngrok CLI for AI Agents

Expose local services and inspect tunnels while controlling network and credential scope.

Official toolOperational risk: R2R3docs-verified
Agent readiness
83/100
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 ngrok/ngrok/ngrok
winget
windows
$ shell
winget install ngrok.ngrok
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 dedicated agent credential and restrict endpoints, domains, and traffic policy.

Methods
authtoken
Secret environment variables
NGROK_AUTHTOKEN
Credential storage
For headless runs, inject NGROK_AUTHTOKEN 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, 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 · yaml · text
Use --log-format=json where supported and keep diagnostic logs on stderr.
--log-format=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.

R0Check configuration
Validates local ngrok configuration without opening a tunnel.
$ shell
ngrok config check
Idempotent
R2Open an HTTP tunnel
Makes a local service reachable from the public network.
$ shell
ngrok http 3000 --log stdout --log-format json
Confirmation requiredMay repeat a changeSensitive output

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 83/100. No local execution test has been recorded.

Structured output
Use --log-format=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 dedicated agent credential and restrict endpoints, domains, and traffic policy.
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
Maintenance is documented by the official publisher source.
5/7
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: ngrok-agent-workflow
description: Use ngrok CLI for local tunnels, webhook testing, traffic inspection with explicit command risk and evidence boundaries.
---

# ngrok CLI agent workflow

Use this skill when the task needs local tunnels, webhook testing, traffic inspection, temporary endpoints.

## 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 ngrok/ngrok/ngrok`
- winget (windows): `winget install ngrok.ngrok`

## Authentication

- Methods: authtoken
- Secret environment variables: `NGROK_AUTHTOKEN`
- Minimum permissions: Use a dedicated agent credential and restrict endpoints, domains, and traffic policy.
- Credential storage: For headless runs, inject NGROK_AUTHTOKEN 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)

- `ngrok config check` — R0: Validates local ngrok configuration without opening a tunnel.

## Commands requiring explicit approval (read-only)

- None recorded.

## Forbidden commands (read-only)

- R2 `ngrok http 3000 --log stdout --log-format json` — Makes a local service reachable from the public network.

## 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 `--log-format=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

- [ngrok agent CLI reference](https://ngrok.com/docs/agent/cli/)

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

Call APIs, inspect protocols, and test webhooks or tunnels.
Develop, deploy, and inspect Cloudflare Workers and related resources.
Reproduce one request with explicit method, headers, body, timeout, and saved response before changing the server or client.
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 ngrok CLI for AI Agents