I’m not interested in flagging other people’s posts, whether I agree with them or not.
I did try my best to translate everything accordingly, just as it was given to me. I had to feed the German letter to a locally hosted translator (used Gemma) with the minimum changes possible, maintaining all the correct data. My English is not good enough for a full “head on” translation and i can’t, and would not, legally provide the assessment with all the data, to an AI translator that could harvest and collect the data for future private and public use.
As a note, and disclosure, personal names, company names, clients and lawyer, they all are redacted due to GPDR and the confidentiality agreement.
I will also ask if i may provide the full assessment to the developer, ,doubting that he will ever want it since he abandoned the project all together. Since this is based on EU laws, no disclosure will be made to third parties such as GamersNexus, Louis Rossman or other interested parties, even European parties.
Everything presented here is a legal, and private assessment only and should be taken as such, by those interested. I will not escalate this further knowing that i, as a consumer and Bambu client, am protected. This is not a commitment from my part to enter a legal dispute (unless it’s needed or my rights are withdrawn forcefully in any way) and is given as an act of good will to the community.
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Date: May 15, 2026
To: (Personal full name and company removed due to GPDR)
Subject: Formal Legal Assessment Regarding Open Source Compliance, Product Interoperability, and Consumer Rights Under European Union Law
Dear Sir/Madam,
I am writing to provide a formal legal assessment, as formally requested, regarding the ongoing and, or, upcoming dispute between Bambu Lab and the open-source community. This assessment addresses the boundaries of software licenses, corporate obligations, and consumer rights under established European Union law.
1. Background and the AGPL Framework
Bambu Studio is not a standalone proprietary creation; it is fundamentally built upon the source code of PrusaSlicer, which operates under the Affero General Public License (AGPL). The AGPL is a binding copyleft agreement that permits a commercial entity to utilize, copy, and modify software free of charge, provided that any subsequent modifications or derivative works are shared openly with the public under the same terms.
To circumvent this requirement, Bambu Lab has implemented a mechanism separating the core open-source slicing software from a proprietary, closed-source network communication plugin. They argue that because this network component is isolated in a separate plugin, they are exempt from public disclosure requirements and retain the right to restrict third-party software from interacting with their cloud servers.
2. The Functional Reality of Combined Works
Under European jurisprudence, this separation is highly fragile. European courts routinely examine the functional reality and operational interdependence of software components rather than a manufacturer’s arbitrary technical labeling.
A primary precedent for this is the landmark Entr’ouvert v. Orange S.A. case, decided on February 14, 2024, by the Paris Court of Appeal. In that matter, the telecommunications giant Orange was ordered to pay significant damages for integrating an open-source library (Lasso) into its proprietary platform while attempting to keep critical dependent modules secret. The Court of Appeal established that if a software platform cannot practically execute its core advertised functions without a specific proprietary component, the software constitutes a “Combined Work.” Consequently, the entire system is subject to the copyleft transparency conditions of the underlying open-source license. Because Bambu Studio is marketed and sold as a cloud-connected tool, the network plugin is an integral element of its operation, meaning an attempt to restrict its code violates the AGPL framework.
3. Technical Identification and the Impersonation Claim
Bambu Lab has issued legal and technical challenges alleging that modified community forks, such as OrcaSlicer, are “impersonating” the official software client when communicating with corporate servers via specific User-Agent strings.
I argue that this claim lacks merit under EU law. The specific technical identifier text used to establish a network handshake is explicitly embedded within the public AGPL source code that Bambu Lab freely published to the world. From a legal standpoint, an entity cannot publish source code under a public license granting explicit permission to copy and modify it, and subsequently initiate claims against the public for utilizing that exact code to facilitate a connection. Under European law, executing public code in a manner permitted by its license does not constitute an identity attack or criminal impersonation; it is a standard technical requirement for cross-platform functionality.
4. Interoperability and the Right to Repair
The European legal framework strongly protects software interoperability and consumer technical autonomy. On October 6, 2021, in Top System v. Belgian State, the Court of Justice of the European Union (CJEU) ruled that a lawful owner of software has an inherent right to decompile, inspect, or modify that software to remedy operational defects or ensure it functions as intended. This underpins a digital “Right to Repair,” confirming that a consumer has a legal right to ensure their purchased hardware remains functional with preferred software tools.
Furthermore, on February 25, 2025, the Grand Chamber of the CJEU issued a definitive ruling in Alphabet and Google v. AGCM (Android Auto). The high court established that a dominant market platform cannot arbitrarily block third-party applications from interoperating with its digital ecosystem simply to favor its own software. The CJEU explicitly raised the evidentiary bar for companies attempting to use “security or platform integrity” as a justification to block third-party access. Because Bambu Lab hardware features a native local network (LAN-only) mode, the machine is demonstrably capable of safely receiving print files without a proprietary cloud layer. Therefore, the argument that third-party community slicers pose an existential security threat fails to satisfy the objective justification standards required by European courts.
5. Consumer Protection and Market Fairness
The retroactive removal or restriction of product capabilities constitutes a severe consumer protection violation. Under EU Consumer Law, specifically Directive 2019/2161 (the Omnibus Directive), manufacturers are prohibited from executing retroactive updates that diminish the core value, interoperability, or functionality of goods already purchased by the consumer.
If a consumer purchases a 3D printer (from any brand and, or, manufacturer) with the reasonable expectation that it supports open community standards and interoperability, a manufacturer cannot later deploy digital locks to restrict those features to force users into a proprietary network ecosystem. Such actions constitute an unlawful vendor lock-in and a retroactive breach of the original consumer sales contract.
In summary, while Bambu Lab utilizes its corporate resources to apply pressure to independent community developers, its legal position within the European Union is exceptionally weak, if none. The company is actively benefiting from the decades of shared work within the open-source community while attempting to deny that same community the reciprocal rights guaranteed by the AGPL license.
When evaluated against the 2024 Entr’ouvert ruling on source code integration, the 2021 Top System decision on functional modifications, and the 2025 Google Android Auto ruling against anti-competitive walled gardens, European law firmly sides with the consumer and the open-source developer. Corporate strategies relying on digital locks and legal intimidation are highly likely to dissolve if subjected to formal adjudication in a European court of law.
Sincerely,
(Independent Advocate, name and company redacted due to GPDR)
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Look at the posting dates… This was before the community guidelines were enforced. These posts will be removed. Thank you for bringing it to my attention.
In whole of this conversation I have not seen one person that is defending bambu that makes a point that would convince me Bambu actions against the dev were justified or proportionate.
The facts stack up against the Bambu and their interpretation. Their practices and conduct are of a school bully, lack of respect for the community that supported them from the start and helped bambu become recognised brand is really telling of what they think about people who helped them become successful.
Without AGPL, Without early adopters and backers on kickstarter (mostly not a first printer buyers) they would not be where they are today.
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Could you do me a favor - only if you want to, of course - and post / mirror it in one of my threads? Then I could pin it. This one:
I get not wanting to flag posts. I was only drawing a distinction between posts being called out in the discussion and posts being formally flagged, since that could explain why one disappears while others stay up.
I would prefer to leave this as it is, from my part. Please, don’t take me wrong or be mad.
You can always share this comment and pin it normally (i think).
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I’m not disagreeing with you on that; I was just asking how you can tell if someone’s life depends on it. That’s your argument. Mine is that it’s going to be pretty hard to prove. Even if that’s the case, it’s just one opinion on a forum.
We must give Bambu credit for one thing: it’s one of the few forums where you can voice critical opinions. Other companies just ban everything outright.
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Im not and never have defended Bambu, I am saying this has nothing to do with open source or AGPL or any of that, if Bambu would give the few here that are upset what they want they throw that poor dev under the bus so fast he wouldn’t know what happened.
Sure, then I’ll only post the link directly to the comment. Thanks. 
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Im not a lawyer but I was expecting this to be the case. I know it is not a judgement but an opinion but it’s an opinion of a legal professional who specialises in the field so brings some clarity and understanding of what we could expect if this went to court in the EU.
To be fair, as i stated before, i was expecting that Bambu were in the right somehow, at least a bit. Not defending them or being against them at all, but it was my thought after reading back and forth this topic. It got confusing.
Some said yes, others said no and i started seeing some right in the wrong and some wrong in the right and in the end i was not expecting that legally they almost had no case.
Just to show that i am also human, above all, and that i also fail.
I don’t want Bambu to burn! Heck no! I want them to grow even more. But what i really want is the commitment that was there originally. Although i am phasing out their machines, due to my own reasons, i still have the H2S laser combo that will stay with me (it’s not worth to sell it) and my beloved A1 Mini that i see as their best printer, all things considered (excluding the X1C).
Some want Bambu to be like Apple. Me? I want them to forget Apple and instead be themselves. There is a way to make money while listening to the community. And the community was the value they brought when they started. That’s what i want… But what i want is irrelevant.
Wish you all a good night.
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Again - you have a license, you have an official FAQ for that license, you have clear statement that what Bambu is doing goes against it, you have all the legal precedents in similar cases. Prove them wrong. Rest - is just fallacies instead of arguments. Please stop using “ad hominem” instead of actual arguments in a discussion, as that doesn’t look good for your position.
Also, any unwarranted requirements doesn’t make your position better, as they don’t make the facts go away.
So I will repeat basically the same thing as I did to 3dEd just a few posts latter: prove the license wrong and prove the FSF lawyers wrong who wrote an FAQ and then prove all existing precedence in similar cases to be a mistrial.
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I don’t want bambu to fail either but I want them to play fairly. They have done a lot of good for 3d printing but then they took the wrong turn. I hope they do come back on the right path. They can achieve much more with backing and respect of open source community.
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What advantages and achievements does this add? If this is true wouldn’t all companies embrace the open source community? Also Prusa has the backing of the open source community but seem to be falling by the way side. Should they not be the number one in the industry because of the open source community?
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Almost all advancements that happen in slicer are driven by open source. Bambu is a follower in this regard. As you can clearly see from their attempts at software they are not the top dog so they can benefit greatly from open source. Even in regards to „cloud security” that they so desperately want. I read somewhere that even their printers software is not 100% proprietary if I remember correctly it is utilising Linux/android for some of the functionality.
So yes, I stand by what I said. They are benefiting greatly from the open source software without giving back.
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- Just ask Google - Android phones are open source, except for the Google apps. Android Open Source Project (AOSP).
- Or how about Amazon? Relies on Linux for nearly all cloud infrastructure.
- Meta (Facebook) - Created React, PyTorch, GraphQL
- IBM / Red Hat - One of the biggest open‑source companies in history
- Even NVIDIA with its AI: CUDA ecosystem integrates with open‑source frameworks
Every major tech company uses open source code, at least at its core - even Apple. MacOS and iOS are built on Darwin (open‑source Unix).
The question is: Which major tech company doesn’t use open source code, at least at its core?
Point by point, this legal opinion is (re)stating everything that several users (myself included) have been repeatedly saying on this matter, with the added benefit of having cited the most relevant EU jurisprudence on similar or identical legal matters. QED.
[Sed lex, dura lex.]
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Not to forgotten, software developers who have confirmed this ages ago - and have actually been working on such topics on a daily basis for decades. However, they don’t post here, but for example on GitHub.
That’s always the fundamental problem with discussions like this: people’s experience is often dismissed, even though there are folks who have been working professionally in the sector for decades. People rarely pay attention to what coders say - who have to take that into account every day. Programming also involves a lot of licensing-related work.
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Best sentence ever posted on the forum.
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