`mty serve`¶

Built-in dev server for a Mighty web-game package. v0.23 Track C.

mty serve reads mighty.toml, builds the package with --target wasm32-web, then serves web/index.html, every static asset under web/, and the freshly-built wasm module on 127.0.0.1:<port>. With --watch, it file-watches src/ and rebuilds + pushes a reload to the page over a websocket on every change.

Synopsis¶

mty serve [--port N] [--watch] [--manifest-dir DIR]

Flags¶

Flag	Description
`--port <N>`	TCP port to bind on `127.0.0.1`. Default `8000`.
`--watch`	Watch `src/` and rebuild on every change. Pushes a reload to connected pages over `ws://127.0.0.1:<port>/_reload`.
`--manifest-dir <DIR>`	Package root (default: current directory).

Routes¶

Method	Path	Behavior
GET	`/`	Serves `web/index.html` with `Content-Type: text/html; charset=utf-8`.
GET	`/<asset>`	Serves `web/<asset>` with a mime type derived from the extension (`.js`, `.css`, `.json`, `.svg`, `.png`, `.jpg`, `.txt`, `.md`, etc.).
GET	`/main.wasm`	Serves the freshly-built wasm artefact (typically `target/main.wasm`) with `Content-Type: application/wasm` and `Cache-Control: no-cache`.
GET	`/_reload`	Websocket upgrade endpoint. The server pushes the string `reload` after every successful `--watch` rebuild; the page template's `dom-shim.js` calls `location.reload()` on receipt.
any	`/<path with ..>`	`403 forbidden` (defence against path-escape attempts).
any	unknown path	`404 not found`.

What it expects¶

The current working directory (or --manifest-dir) must contain:

.
├── mighty.toml
├── src/
│   └── main.mty
└── web/
    └── index.html        # served at `/`

The fastest way to get one is mty new --template web-game <name>.

Build configuration¶

mty serve always builds with:

Setting	Value
target	`wasm32-web`
mode	`debug` (fast rebuild + smaller binary on disk)
output	`<pkg>/target/main.wasm`
wasi-preview	default (`p2`)
component	yes (the same envelope `mty build --target wasm32-web` emits)

The browser-side dom-shim that ships with the web-game template extracts the inner core module from the component envelope at load time — see the comments in templates/web-game/web/dom-shim.js.

`--watch` reload protocol¶

The page opens ws://127.0.0.1:<port>/_reload on first load.
mty serve completes the RFC 6455 opening handshake (Sec-WebSocket-Accept is base64(sha1(key + magic))).
On each successful rebuild, the server writes a single server-to-client text frame containing reload.
The page's dom-shim.js calls location.reload() on receipt.
If the websocket closes (e.g. the server stops), the shim retries every 1s.

Examples¶

# Scaffold a fresh web-game and start the dev loop.
mty new --template web-game asteroids
cd asteroids
mty serve --watch

# Pick a non-default port.
mty serve --port 9000

# Run from outside the package directory.
mty serve --manifest-dir ./asteroids

Exit codes¶

Code	Meaning
`0`	Clean shutdown (Ctrl-C).
`1`	Frontend build error in the user's package (diagnostics printed).
`2`	Backend build error, missing `mighty.toml`, missing `web/`, or bind failure.

mty serve¶