Meteor 3.4.1-beta.1: Rspack consolidation, revitalized examples, and important fixes

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Meteor 3.4.1 is the first patch following the Meteor 3.4 release, aligned with Phase 5: Resource Optimization & Feedback of the Modern Build Stack plan, focused on consolidating the bundler experience introduced.

After Meteor 3.4 introduced the Rspack bundler into core, our team and community have been actively testing and improving it. This patch addresses the feedback collected since then, making the Rspack experience smoother and more reliable across different setups. It also ships revitalized application examples and skeletons, and fixes a DDP session memory leak that affected apps in production.

This release includes contributions from over 25 community members, showing the growing momentum behind the Meteor renaissance. Many of these contributions came from the pending review backlog after the success we had with Hacktoberfest 2025. Thanks to @italojs for his lead on the initiative to get Meteor out on OSS programs like this one, which has brought so many new contributors to the project.

Try the Beta

Meteor 3.4.1-beta.1 is now available for testing. Community testing is key for stability, the more projects that try the beta, the more confident we can be in the final release.

Update Your App

# Update your existing Meteor app to the beta
meteor update --release 3.4.1-beta.1

# Then update npm dependencies (or just run your app once to get them automatically)
meteor update --npm

If you run into any issues after updating, try meteor reset first to clear the local build cache.

Create a New App

# Create a new Meteor app using the beta
meteor create my-app --release 3.4.1-beta.1

If you find any issues, please report them to the Meteor issues tracker.

Highlights

Rspack Integration Improvements

Meteor 3.4.1 makes the Rspack integration easier to adopt, more performant, and more reliable across different setups, addressing the feedback collected since the 3.4 release.

Rspack build logs have been simplified to keep the minimal Meteor style, with opt-in customizations for those who need more detail. CSS handling is now automatically delegated to Rspack, removing the need for manual configuration. We also added support for swc.config.ts configuration files.

New capabilities were added for broader use cases: support for running multiple Rspack instances via METEOR_LOCAL_DIR to isolate build contexts, server-only apps with Rspack, and serving sw.js files during development for HMR-compatible service worker workflows, and Meteor.enablePortableBuild() for deploying a single build artifact across multiple environments.

On the performance side, meteor test --full-app now runs one Rspack process per client and server instead of spawning an extra one, reducing resource usage during testing. TOOL_NODE_FLAGS are now properly inherited in Rspack processes, avoiding memory-related issues in larger projects.

Several environment and compatibility fixes were also included: consistent POSIX-style paths to fix Windows Blaze issues, proper Cordova HMR proxy handling, NODE_ENV override support in tools-core, and a bump of @rsdoctor/rspack-plugin to v1.5.7.

Community contributors also drove important Rspack improvements in this release: @sanki92 added swc.config.ts support, @Shresthap21 improved cache invalidation by tracking local dependencies in rspack.config.js, @9Morello added Preact compatibility checks before adding React dependencies, and @thenileshmishra fixed Rspack CLI type failures with skipLibCheck.

The Rspack documentation has been updated with the latest additions from this release.

Revitalized Application Examples

With all the new possibilities introduced in Meteor 3.4, we reworked the application examples and skeletons to keep the onboarding experience up to date. Newcomers now get a better starting point that reflects the current state of Meteor, and existing users can explore what’s new more easily.

The meteor create command now dynamically fetches examples, and two new options (--from-branch and --from-dir) let you pull projects from any branch or directory in any Git repository. This makes it straightforward to try out different setups, from Rspack configurations to framework combinations, without leaving your terminal.

# List all available examples (use --release to see the new output)
meteor create --release 3.4.1-beta.1 --list

# Create a new app from an example
meteor create my-app --release 3.4.1-beta.1 --example <example-name>

# Create from any external repository
meteor create my-app --release 3.4.1-beta.1 --from https://github.com/fredmaiaarantes/simpletasks

# Or pick a specific branch and directory
meteor create my-app --release 3.4.1-beta.1 --from https://github.com/meteor/examples --from-branch migrate-examples --from-dir parties

# After creating, install npm dependencies
cd my-app && meteor npm install

For a deeper look at each revamped example, see our dedicated post: Revitalized Meteor Examples: Showcasing what Meteor can do today.

@fredmaiaarantes also added a new TypeScript + Tailwind skeleton, a popular combination in the wider JS ecosystem now available as a Meteor skeleton for rapid adoption. Check meteor create --help to see all available skeletons.

DDP Session Memory Leak Fix

A production-impacting bug was fixed where async onStop callbacks in the DDP server were not being awaited, causing session objects to leak memory over time. If your app handles many concurrent subscriptions, this fix alone is worth the upgrade. Thanks to @dupontbertrand for identifying and fixing this.

What Else Is New in Meteor 3.4.1?

Thanks to the commitment of many community contributors, this patch includes a wide range of improvements and fixes beyond the main highlights.

  • Updated to Node v22.22.1, keeping Meteor aligned with the latest LTS. @StorytellerCZ initiated this update.

  • Added support for dots in minimongo key names and concurrency-safe iteration in Minimongo async methods. These long-standing requests improve compatibility with real-world MongoDB document structures.

  • Fixed operator precedence bug in passwordValidator that could reject valid passwords in certain configurations. @slegarraga caught and fixed this.

  • Enabled dev-bundle fast path on Apple Silicon Macs, so meteor node and other dev-bundle commands resolve faster. @sblaisot identified the issue and provided the fix, along with a fix for stale dev-bundle cache after git branch switches.

  • Fixed forgotPassword throwing an error when ambiguousErrorMessages is enabled, and handled deleted PostCSS dependency files gracefully to avoid build crashes. @ebroder contributed the PostCSS fix.

  • Fixed Cordova platforms detection to avoid modern/legacy mismatch. @welkinwong contributed this fix.

  • Added getUserIdsInRoleAsync methods to the roles package with full test coverage. @bratelefant contributed this new async API.

More improvements and fixes were introduced in Meteor 3.4.1, see the changelog.

Big Thanks to Our Contributors

This patch would not have been possible without the active participation of so many community members. We want to highlight how important these contributions have been.

Thanks to our core contributors: @nachocodoner, @italojs, @Grubba27, @zarvox, @calm329, @StorytellerCZ, @sanki92, @bratelefant, @carlosarraes, @graemian, @9Morello, @ReinaT5678, @zodern, @paritoshdey-dev, @dolgarev, @wreiske, @welkinwong, @shamshad-ansari, @ebroder, @sblaisot, @Shresthap21, @thenileshmishra, @slegarraga, @mvogttech, @dupontbertrand, @fredmaiaarantes, and @imajus.

Thanks to all community members for the testing and feedback on Meteor 3.4.1.

What’s Next for Meteor and Beyond?

For the upcoming releases, we have the following priorities.

  • Meteor 3.4.1 official. Once the beta period wraps up and community feedback is addressed, the official 3.4.1 release will follow shortly.
  • Change streams & Node 24. Unified MongoDB change notifications and alignment with newer Node LTS releases. Planned on Meteor 3.5 release / beta already available.
  • Native. Move toward a modern native solution beyond Cordova.

For more details on upcoming work and priorities, see the Meteor roadmap.

Join the Meteor Renaissance!

Meteor 3.4.1 shows how community feedback drives real improvements. From Rspack refinements to production bug fixes, this patch makes your Meteor apps more stable and your development experience smoother.

We’re excited about what’s to come and can’t wait for you to join the Meteor renaissance!

For feedback, questions, or support, visit our forums or join our Discord channel.

If you find any issues, please report them to the Meteor issues tracker.

Follow us on Twitter and GitHub.

Stay tuned, and as always, happy coding! :comet:

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