undefined

undefined

serve-sim [device...]                 # Start preview server (default: localhost:3200)
serve-sim --no-preview [device...]    # Stream only, no web UI
serve-sim gesture '<json>' [-d udid]  # Send a touch gesture
serve-sim button [name] [-d udid]     # Send a button press (default: home)
serve-sim rotate <orientation> [-d udid]
serve-sim ca-debug <option> <on|off> [-d udid]
serve-sim memory-warning [-d udid]    # Simulate a memory warning

undefined

undefined

undefined

┌──────────────┐   simctl io   ┌─────────────────┐  MJPEG / WS  ┌─────────┐
│ iOS Simulator│ ────────────► │ serve-sim-bin   │ ───────────► │ Browser │
└──────────────┘   (Swift)     │ (per-device)    │              └─────────┘
                               └─────────────────┘
                                       ▲
                                  state file in
                                $TMPDIR/serve-sim/
                                       ▲
                               ┌──────────────────┐
                               │ serve-sim CLI /  │
                               │ middleware       │
                               └──────────────────┘

{
  "version": "0.0.1",
  "configurations": [
    {
      "name": "ios",
      "runtimeExecutable": "npx",
      "runtimeArgs": ["serve-sim"],
      "port": 3200
    }
  ]
}

// metro.config.js
const { getDefaultConfig } = require("expo/metro-config");
const connect = require("connect");
const { simMiddleware } = require("serve-sim/middleware");

/** @type {import('expo/metro-config').MetroConfig} */
const config = getDefaultConfig(__dirname);

config.server = config.server || {};
const originalEnhanceMiddleware = config.server.enhanceMiddleware;

config.server.enhanceMiddleware = (metroMiddleware, server) => {
  const middleware = originalEnhanceMiddleware
    ? originalEnhanceMiddleware(metroMiddleware, server)
    : metroMiddleware;

  const app = connect();
  app.use(simMiddleware({ basePath: "/.sim" }));
  app.use(middleware);
  return app;
};

module.exports = config;

import express from "express";
import { simMiddleware } from "serve-sim/middleware";

const app = express();

// First start the helper in daemon mode
// $ npx serve-sim --detach

app.use(simMiddleware({ basePath: "/.sim" }));

app.listen(3000, () => {
  console.log("Dev server at http://localhost:3000");
  console.log("Simulator preview at http://localhost:3000/.sim");
});

// vite.config.ts
import { defineConfig } from "vite";
import { simMiddleware } from "serve-sim/middleware";

export default defineConfig({
  server: {
    middlewareMode: false,
  },
  plugins: [
    {
      name: "serve-sim",
      configureServer(server) {
        // Start helper first: npx serve-sim --detach
        server.middlewares.use("/.sim", simMiddleware({ basePath: "/.sim" }));
      },
    },
  ],
});

// server.ts
import { createServer } from "http";
import { parse } from "url";
import next from "next";
import { simMiddleware } from "serve-sim/middleware";

const dev = process.env.NODE_ENV !== "production";
const app = next({ dev });
const handle = app.getRequestHandler();
const simHandler = simMiddleware({ basePath: "/.sim" });

app.prepare().then(() => {
  createServer((req, res) => {
    const parsedUrl = parse(req.url!, true);
    if (parsedUrl.pathname?.startsWith("/.sim")) {
      return simHandler(req, res, () => handle(req, res, parsedUrl));
    }
    handle(req, res, parsedUrl);
  }).listen(3000);
});

import { simMiddleware } from "serve-sim/middleware";

// Mount options
simMiddleware({
  basePath: "/.sim",  // URL prefix for all serve-sim routes
});

// Middleware exposes:
// GET  /.sim        → Preview HTML UI
// GET  /.sim/api    → State JSON (connected devices, stream URLs)
// GET  /.sim/logs   → SSE log stream from simulator

undefined

undefined

import { simMiddleware } from "serve-sim/middleware";
import connect from "connect";

const app = connect();

// Attach middleware — requires serve-sim helper already running (--detach)
app.use(
  simMiddleware({
    basePath: "/.sim",
  })
);

export default app;

undefined

undefined

git clone https://github.com/EvanBacon/serve-sim
cd serve-sim
bun install

undefined

undefined

**Port already in use**
```sh

**Stream not appearing in middleware**
```sh

**Swift binary not found / won't execute**
```sh

**Multiple simulators — wrong device targeted**
```sh

**Rebuild Swift helper if binary is stale**
```sh
bun run --filter serve-sim build:swift