dev

name	dev
description	Use when the user runs /autumn:dev, asks to start the Autumn development server, enable hot reload, or check what's running locally.
argument-hint	[--package <name>] [--show-config]
allowed-tools	["Bash","Read"]

autumn:dev

Start the Autumn development server with hot reload.

Pre-flight checks

Before running autumn dev, verify:

1. Database URL is configured — check autumn.toml or the env var AUTUMN_DATABASE__PRIMARY_URL is set. autumn dev will fail at startup if no database URL is present. Note: autumn migrate check analyzes migration SQL files only and does NOT test connectivity — to verify the database is reachable, attempt autumn migrate status or start the server and watch the startup logs. autumn dev now auto-loads a project-root .env file (dev/test profiles) into the AUTUMN_* env layer before boot, so you can set AUTUMN_DATABASE__URL there (copy .env.example to .env); real shell env vars still win, and a malformed .env fails loudly.

2. Tailwind binary is present — if autumn setup has not been run:

   autumn setup
   

Execution

autumn dev

For workspace projects, specify the package:

autumn dev --package my-app

To log all registered routes, tasks, middleware, and config at startup:

autumn dev --show-config

autumn dev uses the dev profile automatically in debug builds (AUTUMN_ENV=dev is the default).

On trunk-dev (unreleased — not in the published 0.5.0 CLI) there is also autumn serve for a non-watch local daemon: autumn serve --daemon / stop / status / restart, --release, and --bundled-pg for a managed local Postgres. See docs/guide/daemon.md. Do not suggest it to users on the published 0.5.0 CLI.

What gets served

Once running, tell the user what's available:

Endpoint	Purpose
http://localhost:3000	Application root
http://localhost:3000/health	Simple health check
http://localhost:3000/actuator/health	Detailed health (JSON)
http://localhost:3000/actuator/tasks	Scheduled task status
http://localhost:3000/actuator/jobs	Background job status
http://localhost:3000/static/js/htmx.min.js	Bundled htmx

If autumn-admin-plugin is installed: | http://localhost:3000/admin | Admin dashboard |

If the mail feature is enabled: | http://localhost:3000/_autumn/mail | Mailer preview (dev profile only) |

Hot reload behavior

autumn dev watches src/, templates/, and static/ for changes and recompiles + restarts automatically. Tailwind CSS is rebuilt on template changes.

On trunk-dev (unreleased — not in the published 0.5.0 CLI), when a rebuild fails the browser renders the compiler diagnostics as a full-screen overlay (under a strict nonce-based CSP) instead of leaving a blank or stale page; it clears on the next successful rebuild (issue #1115). See docs/guide/dev-error-overlay.md.

Common failures

Symptom	Fix
Error: Address already in use	Port 3000 is taken. Set AUTUMN_SERVER__PORT=3001 autumn dev or kill the existing process.
Error: connection refused	Database is not running. Start Postgres first.
Compile error shown in terminal	Fix the Rust error; autumn dev will retry on next save.
autumn setup not found	Run cargo install autumn-cli --version 0.5.0

Stopping

Ctrl+C stops the server and the Tailwind watcher.