Astro dev-server recipe (auto-detect fallback)

Loaded when detect-project-type.sh returns astro and the startup tuple still lacks a command.

Signature

• astro.config.js, astro.config.mjs, or astro.config.ts exists
• package.json contains an astro dependency

Start command

Standard:

npm run dev

The dev script in package.json typically wraps astro dev. Also valid (read package.json scripts to confirm which the project uses):

pnpm dev
yarn dev
bun run dev

Prefer the package manager indicated by the lockfile:

• pnpm-lock.yaml -> pnpm dev
• yarn.lock -> yarn dev
• bun.lock / bun.lockb -> bun run dev
• package-lock.json or none -> npm run dev

Port

Default: 4321. Astro respects --port <port> and the server.port field in astro.config.*. Overrides follow the cascade in references/dev-server-detection.md.

Stub generation

{
  "version": "0.2.0",
  "configurations": [
    {
      "name": "Astro dev",
      "runtimeExecutable": "npm",
      "runtimeArgs": ["run", "dev"],
      "port": 4321
    }
  ]
}

Substitute the resolved package manager (npm / pnpm / yarn / bun) and port.

Common gotchas

• SSR vs SSG: astro dev runs identically for both output modes; the difference only matters at build time. Polish does not need to distinguish between them.
• Astro config takes precedence over Vite config: Astro uses Vite under the hood but ships its own config file. The astro type takes precedence over vite when both astro.config.* and vite.config.* exist. This is rare -- Astro projects do not usually have a separate Vite config file.
• Dev toolbar (Astro 4+): Astro 4+ includes a dev toolbar that adds overlay UI in the browser. It does not affect port binding or URL routing -- polish can ignore it.