Prusa Research has pushed another public alpha of its next-generation slicer, and this one fills in a good deal of what the September preview only promised. The PrusaSlicer 3.0.0-alpha13 release notes, published on GitHub on November 2, describe a first working version of the plugin Marketplace, a Print Goals dialog implemented as Lua plugins, a reworked Add printer workflow and a new Material Database tab in the filament selector. The same day, GitHub shows Prusa also published PrusaSlicer 2.9.7, a maintenance release for the current stable branch that exists almost entirely to close security holes.
The pairing is a useful picture of where the project sits right now: one branch being rebuilt from the ground up in public, the other being kept safe for the people who actually depend on it to run printers every day.
A Quick Refresher on 3.0
The 3.0 line was introduced on September 1, 2026, which 3D Printing Industry noted was 15 years to the day after the first Slic3r commit. That preview was not a facelift. The user interface was rebuilt from scratch, and the project system was redesigned so that beds are independent parts, each with its own configuration and without the old nine-bed limit. The profile architecture was reworked as well, allowing things such as per-tool nozzle sizes on the multi-tool XL, and a plugin system was announced with a community marketplace to follow.
Alpha13 is where several of those architectural pieces start to become visible features rather than plumbing.
The Marketplace Arrives, Empty but Signed
The headline addition is the Plugin Marketplace, reachable under Menu > Plugins. Prusa is candid that it launches empty: this release establishes the storefront and the trust model, not the catalog. Plugin bundles are cryptographically signed and verified before they are loaded, and publishing a plugin requires a Prusa Account and passing a basic review.
That design choice matters more than the empty shelves. A slicer plugin runs on the same machine that holds your project files and, increasingly, your printer credentials. Signing bundles and tying publishers to an account gives Prusa a way to establish provenance and, plausibly, to pull a bad actor, which is a sensible baseline for an ecosystem that does not yet exist. It is not a guarantee of safety, and a "basic review" is not an audit, but it is a considerably better starting point than loose scripts copied from a forum thread.
Developers should temper their expectations. The release notes describe the plugin API as experimental, exposing two interfaces at this stage. Anyone building against it now should expect things to move before 3.0 is final.
Print Goals: Prusa Eats Its Own Cooking
The most telling feature in alpha13 is the new Print Goals dialog, because Prusa implemented it as Lua plugins rather than as core code. The initial goals cover vase mode, soluble supports and breakaway supports; the soluble and breakaway goals require a multi-material printer.
The idea is to let a user state an intent, such as "this should be a vase" or "these supports will dissolve," and have the slicer apply the relevant set of changes, instead of making the user hunt through settings tabs to toggle each one individually. The overrides are not permanent: they apply only while a goal is active and do not rewrite the underlying slicer configuration.
Building these on the plugin layer is a strong signal. If Prusa's own first-party features run through the same Lua interface that third parties will use, the API has to be capable enough to carry real workflows, and Prusa has a direct incentive to keep it working. It is the clearest evidence so far that the plugin system is meant to be structural rather than an add-on.
Setting Up Printers and Picking Filament
The Add printer workflow has been restructured into a wizard-style dialog. Users create named local profiles, and physical printer data, the connection details for an actual machine on the network, is now optional rather than bundled into the setup. A new tab in the printer configuration dialog shows the current state of printers connected to Prusa Connect, though Prusa says this is not the final form of printer synchronization.
The filament selector gains a Material Database (MDB) tab. According to the release notes, the database is bundled with the application and does not auto-update, so what ships in a given build is what you get until the next release.
Everything Else in the Changelog
The rest of alpha13 is a mix of restorations and refinements, several of which will matter to specific groups of users:
- SL1 and SL1S profiles are back, restoring support for Prusa's resin printers in the 3.0 branch.
- 3D mouse support has been ported to the new interface.
- 3MF loading and saving is faster, thanks to a move to the libdeflate compression library.
- Wipe tower improvements target tool-changer machines.
- ZIP archives can be opened directly.
- Alpha profiles live in a separate PrusaSlicer3-dev directory, so the alpha can run side by side with a 2.x installation without touching its configuration.
That last item is the practical one for anyone tempted to experiment. Because the alpha keeps its data separate, trying it out does not put a working 2.x setup at risk.
Meanwhile, 2.9.7 Patches the Stable Branch
The PrusaSlicer 2.9.7 release notes, also dated November 2 on GitHub, describe a maintenance release focused on security. The fixes include an out-of-bounds write triggered by loading a 3MF file with a negative bed index, a stack buffer overflow in the digits() and zdigits() placeholder functions, issues in the Printables downloader, and vulnerabilities in libbgcode involving malformed binary G-code. Prusa credits the reporter, @5un9hun, who disclosed the issues responsibly.
Several of those bugs sit in the path of files makers routinely download from strangers: project files and G-code. A memory-safety flaw in a file parser is exactly the kind of bug that turns "open this model" into a risk, which makes this an update to install rather than defer.
What It Means for Makers
For anyone printing production parts or running a farm, the action item this week is 2.9.7, not 3.0. Update the stable branch, particularly if you regularly open 3MF projects or binary G-code that you did not create yourself.
Alpha13 is for the curious and for would-be plugin authors. The separate PrusaSlicer3-dev profile directory makes it safe to install alongside your daily driver, and the Print Goals dialog offers a concrete look at how intent-driven slicing might replace a lot of manual settings work. Plugin developers can start studying the experimental API, with the understanding that it is not yet stable and the Marketplace has nothing in it.
The larger story is architectural. By routing its own features through signed, Lua-based plugins, Prusa is betting that the next version of its slicer will be defined as much by what can be added to it as by what ships in the box. Whether a community actually shows up to fill that Marketplace is the open question for the rest of the 3.0 cycle.
