OtterKit is a powerful desktop application for local development on macOS. It helps you create .localhost domains with automatic HTTPS, share your local server via public tunnels, test webhooks, and inspect HTTP traffic - all from one beautiful interface.

Is there a free trial?

Yes! OtterKit offers a 3-day free trial with full access to all features. No credit card required. After the trial, you can purchase a Pro license for $29/year to continue using OtterKit.

What operating systems does OtterKit support?

Currently, OtterKit is available for macOS 12.0 (Monterey) and later. We support both Apple Silicon (M1/M2/M3) and Intel-based Macs. Windows and Linux versions are on our roadmap.

How do .localhost domains work?

OtterKit acts as a local DNS resolver and reverse proxy. When you create a domain like myapp.localhost, OtterKit registers it with your system and routes all requests to your specified local port. This happens entirely on your machine with no external services.

Are the SSL certificates trusted by browsers?

Yes! When you trust OtterKit's Certificate Authority (CA), all certificates it generates are trusted by every browser on your machine. You'll see the green padlock just like on production sites.

How do public tunnels work?

Public tunnels create a secure connection between a public URL and your local server. When someone accesses the public URL, the request is securely forwarded to your machine. Tunnels are great for client demos, webhook testing, and mobile device testing.

Can I use OtterKit with any local server?

Absolutely! OtterKit works with any HTTP server running on your machine - Node.js, Python, Ruby, Go, PHP, or any other framework. Just point OtterKit to the port your server runs on.

Does OtterKit require an internet connection?

Local domains and HTTPS work completely offline. Public tunnels and CLI tunnels require an internet connection since they route traffic through external servers. The Traffic Inspector works regardless of internet connectivity.

Can AI agents use OtterKit?

Yes! The OtterKit CLI allows AI agents to provision tunnels programmatically with a single command. Agents pay per tunnel using MPP (Machine Payments Protocol) with USDC or pathUSD via Tempo Wallet or mppx. The CLI auto-detects which wallet is available. No desktop app installation required, just run npx otterkit tunnel .

How do daemon tunnels work?

Daemon tunnels run as background processes that survive terminal close. You pay a flat fee based on duration (1 minute to 24 hours). The tunnel auto-expires when the TTL runs out. Use npx otterkit status to check running daemons and npx otterkit stop to stop one.

How do CLI webhooks work?

The npx otterkit webhook command creates a webhook endpoint that captures incoming HTTP requests without needing a local server. You get a public URL that you can point any third-party service (Stripe, GitHub, Slack, etc.) to. All incoming requests are captured and displayed with full headers, body, and metadata. Webhooks use the same pricing as tunnels: $0.01 for foreground, TTL-based pricing for daemon mode.

How does file sharing work?

The npx otterkit share command generates public download URLs for local files or directories. It spins up a tiny local HTTP server and tunnels it, so anyone with the link can download files directly from your machine. Supports single files, multiple files, and entire directories. Multiple files get an auto-generated index page. Costs $0.01 for foreground, with daemon mode support for background sharing.

What is the intercept command?

The npx otterkit intercept command combines tunnels and webhooks. It captures every HTTP request to a local JSONL file while forwarding to your local server. Use npx otterkit intercept 3000 for capture + forward, or npx otterkit intercept for capture-only mode. View captured requests with npx otterkit inspect . Same pricing as tunnels. Great for debugging webhook integrations like Stripe or GitHub.

OtterKit - Local Development Toolkit for Modern Developers

Name: OtterKit
Rating: 4.9 (127 reviews)
Author: OtterKit

Built for humans & AI agents

The local dev toolkit for domains, tunnels & webhooks

Manage local domains, spin up instant secure URLs, and inspect traffic, all from a beautiful native app, or a single CLI command your agents can run.

Local DomainsAuto HTTPSPublic TunnelsWebhooksTraffic InspectorPort ManagerFile SharingPay Per Use

For Humans

Native macOS app

Beautiful interface for your daily workflow. $29/year · 3-day free trial.

For AI Agents

One CLI command

Pay-per-use micropayments. No API keys, no accounts, no setup.

100% localNo API keys neededWorks with any agent

Features

Everything you need for local development

Stop juggling multiple tools. OtterKit brings all essential local development features into one elegant interface.

Local Domains

Create beautiful .localhost domains for your projects. No more remembering port numbers.

Auto HTTPS

Automatic SSL certificates with one-click trust. Get the green lock in your browser instantly.

Public Tunnels

Share your local server with anyone. Get a public URL in seconds, no configuration needed.

Webhook Testing

Create instant webhook endpoints. Capture, inspect, and replay incoming requests.

Traffic Inspector

Real-time HTTP traffic monitoring. See every request and response with full details.

Port Manager

See what processes are running on any port. Kill them instantly and save favorites.

Certificate Manager

Full control over your SSL certificates. Trust, regenerate, or export with ease.

CLI for Agents

Tunnels & webhooks for AI agents

One command to expose any local port or create a webhook endpoint. No desktop app, no sign-up. Pay per tunnel with USDC or pathUSD via Tempo Wallet or mppx. Auto-detects your wallet.

Terminal

$ npx otterkit tunnel 3000
Using Tempo Wallet (0x1e69...)
Initializing payment...
Provisioning tunnel...
Tunnel provisioned: agent-a1b2c3d4
  Tunnel ready: https://agent-a1b2c3d4.otterkit.app → localhost:3000
  Press Ctrl+C to disconnect
$ curl https://agent-a1b2c3d4.otterkit.app
  200 GET / (12ms)

Instant Setup

One command to expose any local port or create a webhook endpoint. No desktop app, no config files, no sign-up.

Pay Per Use

MPP payments with USDC or pathUSD via Tempo Wallet or mppx. From $0.01 per tunnel or webhook. Auto-detect or use --wallet flag.

Daemon Mode

Background tunnels and webhooks that survive terminal close. Auto-expire after TTL. From 1 minute to 24 hours.

Webhook Endpoints

Capture incoming HTTP requests without a local server. Point any service to your webhook URL.

Intercept & Inspect

Capture + forward in one command. Log every request to a file while forwarding to your local server. Inspect and replay later.

File Sharing

Generate a public download URL for any local file with one command. Correct MIME types and browser downloads.

What agents use OtterKit for

Expose a dev server

Agent spins up a local app and needs a public URL for testing or sharing with a user.

Receive webhooks

Agent sets up a Stripe or GitHub webhook endpoint to test an integration end-to-end.

Share build artifacts

Agent generates a report or build output and creates a download link for the user.

Background services

Agent provisions a daemon tunnel that stays alive for hours while it works on other tasks.

Debug API integrations

Agent uses intercept mode to capture and inspect every request flowing through a tunnel.

Multi-agent collaboration

One agent exposes a service, another agent consumes it via the public URL.

Get started in 30 seconds:

Configuration needed

100%

Native performance

Built-in tools

Why OtterKit

Built for developers who value their time

OtterKit is designed to get out of your way and let you focus on what matters: building great software.

No configuration files to manage

Works with any local server

Native macOS performance

Beautiful, intuitive interface

Instant setup, zero dependencies

100% private - runs entirely on your machine

Pricing

Two ways to use OtterKit

A desktop app for your full local development workflow, or a CLI for instant agent tunnels and webhooks.

Desktop App

3-day free trial

OtterKit Pro

Full local development toolkit for macOS

$29/ year

3-day free trial

Unlimited local domains

Unlimited public tunnels

Unlimited webhooks

Auto HTTPS certificates

Traffic inspector

Port manager

Request replay

Priority support

All future updates

Subscribe - $29/year

CLI for Agents

No sign-up

Pay Per Use

Instant tunnels and webhooks for AI agents via MPP

from$0.01/ tunnel

ModeDurationPrice

ForegroundWhile terminal is open$0.01

1 minuteQuick test$0.01

1 hourDefault daemon$0.01

4 hoursExtended session$0.03

12 hoursHalf day$0.05

24 hoursFull day$0.08

No sign-up or subscription

Pay with USDC or pathUSD via Tempo mainnet

Tempo Wallet or mppx (auto-detected)

Works with any AI agent

Get Started with CLI

FAQ

Frequently Asked Questions

Everything you need to know about OtterKit.

OtterKit - Your local dev toolkit

The local dev toolkit for domains, tunnels & webhooks

Native macOS app

One CLI command

Everything you need for local development

Local Domains

Auto HTTPS

Public Tunnels

Webhook Testing

Traffic Inspector

Port Manager

Certificate Manager

Tunnels & webhooks for AI agents

Instant Setup

Pay Per Use

Daemon Mode

Webhook Endpoints

Intercept & Inspect

File Sharing

What agents use OtterKit for

Built for developers who value their time

Two ways to use OtterKit

OtterKit Pro

Pay Per Use

Frequently Asked Questions

What is OtterKit?

Is there a free trial?

What operating systems does OtterKit support?

How do .localhost domains work?

Are the SSL certificates trusted by browsers?

How do public tunnels work?

Can I use OtterKit with any local server?

Does OtterKit require an internet connection?

Can AI agents use OtterKit?

How do daemon tunnels work?

How do CLI webhooks work?

How does file sharing work?

What is the intercept command?