✨ Major Changes

• #16610 c63e7e4 Thanks @matthewp! - Adds background dev server management for AI coding agents.

  When an AI coding agent is detected, astro dev now automatically starts the dev server as a detached background process. This prevents the dev server from blocking the agent’s terminal and allows it to continue working while the server runs.

  A lock file (.astro/dev.json) is written when the dev server starts, recording the server’s URL, port, and PID. This prevents duplicate servers from being started for the same project.

  New flag and subcommands

  • astro dev --background — Start the dev server as a background process (this is what runs automatically when an agent is detected).
  • astro dev stop — Stop a running background dev server.
  • astro dev status — Check if a dev server is running and display its URL, PID, and uptime.
  • astro dev logs — View logs from a background dev server. Use --follow (-f) to stream new output as it’s written.

  These allow you to start and manage dev servers programmatically and were designed with AI coding agents in mind.

  What should I do?

  No action is required. If you are not using an AI coding agent, astro dev behaves exactly as before. If you are using an agent, background mode is enabled automatically — the agent will receive the server URL and PID, and can use astro dev stop to shut it down.

  To opt out of automatic background mode when an agent is detected, set the environment variable ASTRO_DEV_BACKGROUND=0 before running astro dev.

• #16725 10229f7 Thanks @ArmandPhilippot! - Removes deprecated APIs exported from astro:transitions.

  In Astro 6.x, some helpers available in astro:transitions and astro:transitions/client were deprecated.

  In Astro 7.0, the following APIs can no longer be used in your project:

  • TRANSITION_BEFORE_PREPARATION
  • TRANSITION_AFTER_PREPARATION
  • TRANSITION_BEFORE_SWAP
  • TRANSITION_AFTER_SWAP
  • TRANSITION_PAGE_LOAD
  • isTransitionBeforePreparationEvent()
  • isTransitionBeforeSwapEvent()
  • createAnimationScope()

  What should I do?

  Remove any occurrence of createAnimationScope():

  import { createAnimationScope } from 'astro:transitions';

  Replace any occurrence of the other APIs using the lifecycle event names directly:

  import {
    TRANSITION_AFTER_SWAP,
    isTransitionBeforePreparationEvent,
  } from 'astro:transitions/client';
  
  console.log(isTransitionBeforePreparationEvent(event));
  console.log(event.type === 'astro:before-preparation');
  
  console.log(TRANSITION_AFTER_SWAP);
  console.log('astro:after-swap');

  Learn more about all utilities available in the View Transitions Router API Reference.

🐞 Patch Changes

• #16980 1f07343 Thanks @matthewp! - Removes state.provide(), state.resolve(), state.finalizeAll(), and App.Providers from the public advanced routing API. These context provider extension points are now internal-only. If you were using them in an integration, use locals to share per-request state instead.

• #16982 1e000e2 Thanks @matthewp! - Improves the warning when accessing Astro.session without session storage configured. The session property is now always defined on the context object, and accessing it without configuration logs a helpful message instead of silently returning undefined.

• #16990 ebeb830 Thanks @ocavue! - Fixes Astro.request.url not reflecting validated X-Forwarded-Proto/X-Forwarded-Host headers when security.allowedDomains is configured. Previously, only Astro.url was updated with the forwarded origin while Astro.request.url retained the socket-derived URL, causing the two to diverge behind TLS-terminating proxies.