dev-proxy

Subdomain-based reverse proxy with a real-time HTTP/WS traffic inspector TUI.

Built for agentic development workflows where dozens of services, worktrees, and AI-driven coding sessions run simultaneously — one proxy to route them all, one terminal to see everything.

Routes *.{domain}:3000 requests to local services by subdomain and displays all traffic in a terminal dashboard. Think of it as a lightweight, terminal-native alternative to tools like Charles or Proxyman — purpose-built for local multi-service development.

한국어 문서 (Korean)

Why dev-proxy?

When developing with multiple local services (frontend, API, auth, docs, admin...), you need a way to route requests by subdomain and see what's happening. Existing options are either too heavy (nginx, Caddy) or GUI-only (Charles, Proxyman).

dev-proxy is:

• Zero-config start — Works out of the box with localhost and auto-generated TLS certs
• Terminal-native — No browser windows to manage; lives where you already work
• Vim-style navigation — j/k to browse, / to search, r to replay
• Worktree-aware — Routes branch--app.domain to per-worktree ports automatically
• Lightweight — Two runtime dependencies (ink + react), ~10fps throttled rendering

Features

• Real-time HTTP request/response monitoring (method, status, size, latency)
• WebSocket connection tracking (OPEN / CLOSED / ERROR)
• Request/response header, cookie, and query parameter inspection
• Noise filter (_next/, favicon), error-only mode, URL/method search
• Request replay with original headers and curl copy to clipboard
• Upstream http/https and ws/wss target support
• Git worktree-based dynamic routing via project config
• Auto-generated TLS certificates via mkcert
• Project-based config: global (~/.dev-proxy/config.json) + per-project (dev-proxy.config.mjs for routes, .dev-proxy.json for worktreeConfig, .dev-proxy.worktrees.json for the CLI-managed worktree map)

Prerequisites

• Node.js >= 20.11
• mkcert (optional, for HTTPS) — brew install mkcert && mkcert -install

Quick Start

For Humans

npm install -g @reopt-ai/dev-proxy
dev-proxy init
dev-proxy

Press Enter to arm the inspector, then open http://www.example.dev:3000 in your browser.

For AI Agents

Option 1 — Claude Code skill (recommended):

npx skills add reopt-ai/dev-proxy

Then tell Claude Code: "setup dev-proxy" — it will detect your project structure, suggest routes, and generate config files automatically.

Option 2 — Any AI agent:

Paste this to your AI coding agent (Claude Code, Cursor, Copilot, etc.):

Install and configure dev-proxy by following the instructions here: https://raw.githubusercontent.com/reopt-ai/dev-proxy/main/docs/guide/installation.md

Install

# npx (no install)
npx @reopt-ai/dev-proxy

# Global install
npm install -g @reopt-ai/dev-proxy

# From source
git clone https://github.com/reopt-ai/dev-proxy.git
cd dev-proxy && pnpm install && pnpm proxy

Configuration

Config is split into four files:

1. ~/.dev-proxy/config.json — Global settings (domain, ports, TLS, project list)
2. <project>/dev-proxy.config.mjs — Per-project routes (canonical format)
3. <project>/.dev-proxy.json — Per-project worktreeConfig (only required if you use git worktree routing). Hand-edited.
4. <project>/.dev-proxy.worktrees.json — CLI-managed worktree instance map (dev-proxy init writes an empty placeholder; the worktree CLI commands keep it in sync — do not edit by hand)

Easiest path: run dev-proxy init from your project directory and the wizard creates these files for you. The sections below cover the file format if you'd rather author them by hand.

Global Config (~/.dev-proxy/config.json)

{
  "domain": "example.dev",
  "port": 3000,
  "httpsPort": 3443,
  "projects": ["/path/to/your/project"]
}

Project Routes (dev-proxy.config.mjs)

Place a dev-proxy.config.mjs in each project root registered in projects. Routes are defined here.

/** @type {import('@reopt-ai/dev-proxy').Config} */
export default {
  routes: {
    "@": "http://localhost:3005",
    www: "http://localhost:3001",
    studio: "http://localhost:3001",
    api: "http://localhost:4000",
    "*": "http://localhost:3001",
  },
};

• "@" matches the apex (bare) domain — e.g. reopt.de itself, with no subdomain. Optional; falls back to "*" if absent.
• "*" is a wildcard — unmatched subdomains route here
• When multiple projects register the same subdomain, the first one wins
• certPath/keyPath are set in the global config, resolved relative to ~/.dev-proxy/
• dev-proxy.config.js is also accepted (used when package.json has "type": "module"); .mjs takes precedence if both exist
• Resolution order at runtime: dev-proxy.config.mjs → dev-proxy.config.js → .dev-proxy.json (legacy fallback for routes)
• The CLI-managed worktrees map always lives in .dev-proxy.worktrees.json. worktreeConfig (if present) stays in .dev-proxy.json and is hand-edited.

Migrating from .dev-proxy.json

Earlier versions stored everything (routes, worktreeConfig, and the worktrees instance map) in .dev-proxy.json. The format still works at read time, but dev-proxy.config.mjs + .dev-proxy.worktrees.json is the documented split. To migrate every registered project at once:

dev-proxy migrate

The command moves routes from .dev-proxy.json into dev-proxy.config.mjs, moves the worktrees instance map into .dev-proxy.worktrees.json, and leaves worktreeConfig (if any) in .dev-proxy.json. When .dev-proxy.json would otherwise be empty after the split, it is removed. The command is idempotent and projects already migrated are skipped.

HTTPS

Certificates are stored in ~/.dev-proxy/certs/. If missing, they are auto-generated using mkcert.

brew install mkcert
mkcert -install

When mkcert is installed, dev-proxy automatically generates wildcard certificates on first run. No manual steps needed.

Worktree Routing

dev-proxy supports git worktree-based dynamic routing. When you use branch--app.domain as the hostname, it routes to a per-worktree port.

Automatic lifecycle management:

Routes go in dev-proxy.config.mjs; the worktreeConfig schema goes in .dev-proxy.json (you author this); the live worktrees instance map goes in .dev-proxy.worktrees.json (the CLI manages this). Use services to define per-subdomain port mappings — dev-proxy allocates ports automatically and generates a .env.local file so your dev servers know which port to listen on:

// dev-proxy.config.mjs
/** @type {import('@reopt-ai/dev-proxy').Config} */
export default {
  routes: {
    www: "http://localhost:3001",
    data: "http://localhost:4001",
    "*": "http://localhost:3001",
  },
};

// .dev-proxy.json
{
  "worktreeConfig": {
    "portRange": [4101, 5000],
    "directory": "../myproject-{branch}",
    "services": {
      "www": { "env": "PORT" },
      "data": { "env": "DATA_PORT" }
    },
    "envFile": ".env.local",
    "hooks": {
      "post-create": "pnpm install",
      "post-remove": "echo cleanup done"
    }
  }
}

// .dev-proxy.worktrees.json (CLI-managed — do not hand-edit)
{
  "worktrees": {
    "main": { "ports": { "www": 3001, "data": 4001 } }
  }
}

Then create and destroy worktrees with a single command:

dev-proxy worktree create feature-auth
# → git worktree add
# → allocates ports: www=4101, data=4102
# → writes .env.local: PORT=4101, DATA_PORT=4102
# → runs post-create hook (pnpm install)

dev-proxy worktree destroy feature-auth
# → runs post-remove hook, git worktree remove, releases ports

How routing works:

• feature-auth--www.example.dev:3000 → routes to port 4101 (www service)
• feature-auth--data.example.dev:3000 → routes to port 4102 (data service)
• Config file is watched live — routing updates instantly on changes
• Unregistered worktrees show an offline error page instead of silently falling back

Manual mode (without worktreeConfig):

dev-proxy worktree add feature-auth 4001    # Register single port (no git operations)
dev-proxy worktree remove feature-auth      # Unregister only

Usage

# If installed globally or via npx
dev-proxy

# From source
pnpm proxy

# Debug mode (tsx, no build step)
pnpm proxy:src

pnpm proxy builds dist/ first, then runs with NODE_ENV=production to avoid Ink/React dev-mode memory leaks.

UI States

The TUI has three states:

1. Splash — Shows configured routes and listening ports. Press Enter to arm.
2. Inspect — Live traffic dashboard with list + detail panels.
3. Standby — Auto-sleeps after 60s of no interaction to reduce memory pressure. Press I or Enter to resume.

Keybindings

Navigation

| Key | Action | | --------- | --------------------------- | | ← / → | Switch list / detail focus | | j / ↓ | Next request | | k / ↑ | Previous request | | g | Jump to first | | G | Jump to last | | Enter | Open detail panel | | Esc | Back to list / clear search |

Detail Panel

| Key | Action | | --------- | ------ | | ↑ / ↓ | Scroll |

Focusing the detail panel automatically disables Follow mode so your selection stays put.

Filters & Actions

| Key | Action | | --- | ------------------------------------------ | | / | Search mode (filter by URL or method) | | f | Toggle Follow mode | | n | Toggle noise filter (_next, favicon) | | e | Toggle error-only mode | | x | Clear all traffic and filters | | r | Replay selected request (with headers) | | y | Copy selected request as curl to clipboard |

Mouse

• Scroll in list or detail panel
• Click a row to select it
• Click header filter badges to toggle them

Security

This is a development tool and makes deliberate trade-offs for local development convenience:

• rejectUnauthorized: false — The proxy accepts self-signed certificates from upstream targets. This is intentional so that dev services using mkcert or self-signed certs work without extra configuration. Do not use this proxy in production.
• No authentication — The proxy binds to localhost by default with no auth layer.

Troubleshooting

Port already in use

Error: port 3000 is already in use (another dev-proxy instance may already be running)

Kill the existing process or use a different port in your config:

# Find and kill
lsof -ti :3000 | xargs kill

# Or change port
# Or change port in ~/.dev-proxy/config.json: "port": 3080

mkcert not found

HTTPS disabled — mkcert not found.

HTTPS is optional. Install mkcert for TLS support:

brew install mkcert    # macOS
mkcert -install

Next.js HMR / origin errors

Next.js >= 15.0 validates the Origin header on dev server requests. When accessing via dev-proxy (e.g., http://web.localhost:3000), the origin differs from what Next.js expects, causing blocked requests or HMR failures.

Add allowedDevOrigins to your next.config.mjs:

const nextConfig = {
  allowedDevOrigins: ["http://web.localhost:3000"],
};
export default nextConfig;

Add one entry per subdomain that routes to a Next.js service. If using HTTPS, also add the https:// variant.

Blank screen / Raw mode error

If you see Raw mode is not supported, you're running in a non-TTY context (e.g., piped output, CI). dev-proxy requires an interactive terminal.

Request not routing to expected target

1. Check the splash screen — it lists all configured routes
2. Verify your Host header matches subdomain.domain:port
3. Ensure the target service is actually running on the configured port

CLI Reference

| Command | Description | | -------------------------------------- | ------------------------------------------------------------------------ | | dev-proxy | Start proxy and open traffic inspector | | dev-proxy init | Interactive setup wizard | | dev-proxy migrate | Split legacy .dev-proxy.json into .mjs + .dev-proxy.worktrees.json | | dev-proxy status | Show configuration and routing table | | dev-proxy doctor | Run environment diagnostics | | dev-proxy config | View global settings | | dev-proxy config set <key> <value> | Modify global settings (domain, port, httpsPort) | | dev-proxy project add [path] | Register a project (default: cwd) | | dev-proxy project remove <path> | Unregister a project | | dev-proxy project list | List registered projects | | dev-proxy worktree create <branch> | Create worktree with auto port + hooks | | dev-proxy worktree destroy <branch> | Destroy worktree with hooks + cleanup | | dev-proxy worktree add <name> <port> | Register worktree manually (no git operations) | | dev-proxy worktree remove <name> | Unregister worktree manually | | dev-proxy worktree list | List all worktrees | | dev-proxy --help | Show help | | dev-proxy --version | Show version |

Architecture

src/
├── cli.ts                 # Subcommand router
├── index.tsx              # TUI dashboard (Ink render + proxy lifecycle)
├── store.ts               # External store (useSyncExternalStore)
├── commands/              # CLI subcommands (Ink components)
│   ├── init.tsx           # Interactive setup wizard
│   ├── status.tsx         # Configuration overview
│   ├── doctor.tsx         # Environment diagnostics
│   ├── config.tsx         # Config view/set
│   ├── project.tsx        # Project management
│   ├── worktree.tsx       # Worktree management
│   ├── help.tsx           # Help output
│   └── version.tsx        # Version output
├── bootstrap.ts           # Startup bootstrapper (config load, proxy init)
├── cli/                   # Shared CLI components
│   ├── config-io.ts       # Config I/O helpers and port allocation
│   └── output.tsx         # Display components (Header, Section, Check, etc.)
├── proxy/
│   ├── config.ts          # Config loader (~/.dev-proxy + .mjs / .dev-proxy.json / .dev-proxy.worktrees.json)
│   ├── server.ts          # HTTP/WS reverse proxy
│   ├── routes.ts          # Subdomain → target routing
│   ├── certs.ts           # TLS certificate resolution (mkcert)
│   ├── worktrees.ts       # Dynamic worktree port registry
│   └── types.ts           # Event types
├── components/
│   ├── app.tsx             # Root (resize, keyboard, state machine)
│   ├── splash.tsx          # Splash screen
│   ├── status-bar.tsx      # Top status bar
│   ├── request-list.tsx    # Request list (viewport slicing)
│   ├── detail-panel.tsx    # Detail panel (scrollable)
│   └── footer-bar.tsx      # Bottom keybinding hints
├── hooks/
│   └── use-mouse.ts        # SGR mouse event parser
└── utils/
    ├── format.ts           # Color palette, formatters
    └── list-layout.ts      # Responsive column layout

Contributing

See CONTRIBUTING.md for development setup and guidelines.

License

MIT