# Dev

> Build and start the merjs dev server with hot reload. Use when the user wants to run, start, or serve the project.

- Skill: `justrach/dev` (Agent Skill)
- Install (CLI): `npx skillmds@latest add justrach/dev`
- Raw SKILL.md: https://api.skillmd.com/api/skills/justrach/dev/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: justrach (https://skillmd.com/u/justrach)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/justrach/dev

---


# Start merjs dev server

## Steps

1. Kill any existing process on port 3000:
   ```bash
   lsof -ti :3000 | xargs kill -9 2>/dev/null
   ```

2. Regenerate routes (in case pages changed):
   ```bash
   zig build codegen
   ```

3. Build the project:
   ```bash
   zig build
   ```

4. Start the dev server in the background:
   ```bash
   ./zig-out/bin/merjs --port 3000 &
   ```

5. Wait 2 seconds, then verify the server is listening:
   ```bash
   lsof -i :3000 -sTCP:LISTEN
   ```

6. Tell the user the server is running at http://localhost:3000

## Flags

- `--port N` — listen on a different port
- `--no-dev` — disable hot reload (SSE watcher)
- `--prerender` — pre-render SSG pages to dist/ and exit