Bambu Lab, the company behind some of the most popular and accessible 3D printers on the market, is facing an unprecedented backlash from the open-source community. The controversy began with a single private message sent on Reddit to developer Paweł Jarczak, requesting that he remove his code from GitHub. That message has since snowballed into a full-blown revolt, with prominent figures in the tech and maker communities pledging support for Jarczak and daring Bambu to take legal action.

The spark: A DM that backfired

On April 22nd, Bambu Lab contacted Jarczak via Reddit, asking him to delete a project that allowed users to control Bambu printers without using the company’s proprietary software. The message was initially polite, but quickly escalated into threats of legal action under the Digital Millennium Copyright Act. Jarczak initially agreed to remove his code, but left a note accusing Bambu of treating him like a criminal. This note went viral, drawing attention from the broader open-source world.

Jarczak had created a fork of OrcaSlicer—itself a fork of Bambu Studio—that bypassed Bambu’s authentication system. He argued that his work was simply a natural extension of the open-source AGPL license under which Bambu distributed its software. The company, however, viewed his code as an unauthorized workaround that impersonated its systems and threatened security.

Community backlash: A united front

The response was swift and forceful. Consumer rights advocate Louis Rossmann publicly pledged $10,000 to defend Jarczak in court, stating, “I’ll put up $10,000 to teach Bambu Labs a lesson.” Maker Jeff Geerling declared he would never buy another Bambu printer and offered to contribute to Jarczak’s legal fund. The hardware review site GamersNexus matched Rossmann’s pledge and revealed that it had cancelled previously unannounced plans to spend $150,000 on Bambu hardware for a 3D printing project. Editor-in-chief Steve Burke told the media, “Go ahead, Bambu: Sue us.”

Even the Software Freedom Conservancy (SFC) entered the fray, launching a project to reverse engineer Bambu’s code and serve as a watchdog. Bradley Kühn, the creator of the AGPL license, publicly accused Bambu of violating the terms of its open-source license. “They’re bad actors, straight-up,” he said.

The heart of the issue: Open-source vs. control

At its core, the conflict revolves around the AGPL license. Bambu Studio, the slicing software used by its printers, is based on PrusaSlicer, which in turn originated from Slic3r and the RepRap community. All of these are open-source projects released under the AGPL. This license grants anyone the right to use, modify, and distribute the code, provided they share any changes under the same terms. However, Bambu added a proprietary networking plugin that controls how the software communicates with its cloud service and printers.

When Bambu updated its firmware to block third-party accessories, Jarczak created a version of OrcaSlicer that used code from Bambu Studio’s Linux release, effectively circumventing the authentication check. Bambu argued that this violated its terms of service and constituted impersonation. Jarczak countered that his code simply identified itself as “BambuStudio”—a string present in Bambu’s own open-source code—and that any vulnerability lay in Bambu’s servers, not in his work.

Legal gray areas

The legal landscape is murky. Open-source attorney Kyle Mitchell noted that the AGPL does not clearly define how far its source-sharing obligations extend when cloud services are involved. Heather Meeker, an expert in open-source licensing, added that plug-ins generally fall under “Corresponding Source,” but courts have rarely weighed in on these questions. Bambu itself argued that its networking plugin is “separately delivered” and thus exempt from AGPL requirements.

The SFC is currently pursuing a similar case against Vizio, arguing that the company failed to release source code for its smart TVs under the GPL. That case is set for trial in August and could set a precedent. However, neither side has yet filed a formal lawsuit in this matter, leaving the battle largely in the court of public opinion.

Security concerns or lock-in strategy?

Bambu defended its actions by citing security. The company claimed it faced millions of “abnormal requests,” including DDoS attacks, and that Jarczak’s code could be exploited by malicious actors. Critics pointed out that Bambu could have closed the security gap on its servers rather than threatening a single developer. Jarczak stated, “A cloud service should enforce authorization on the server side with proper account/device authorization, token scopes, quotas, per-account limits, per-device limits, rate limiting, abuse detection, and clear API rules.” Bambu has since indicated that it will implement enhanced authentication measures, but has not provided a timeline.

Community members suspect that Bambu’s true motive is to lock users into its ecosystem, potentially charging for subscriptions or forcing the use of proprietary filaments and accessories. Bambu did not deny these possibilities when questioned. This fear mirrors the “enshittification” seen in inkjet printer markets, where companies like HP have used software to restrict third-party ink cartridges.

What’s next?

The open-source community is organizing. The SFC aims to raise $250,000 to hire staff dedicated to “liberating AGPLv3-violating 3D printers.” Rossmann’s group has pledged $15,000 toward that goal. Thousands of developers have forked Jarczak’s original code, daring Bambu to sue them. Bambu, for its part, has softened its tone, stating that it regrets the communication failure and is focusing on internal infrastructure improvements rather than escalating conflict.

Kühn believes the solution is simple: Bambu should release all of its code, as its business is hardware sales, not software licensing. Alternatively, it could rewrite its software from scratch, avoiding AGPL code altogether. Jarczak agrees but warns, “I do not think ‘fully closed’ would be better for users. It would just be more honest.”

The outcome of this standoff could redefine the relationship between hardware manufacturers and the open-source community. If Bambu backs down, it would set a strong precedent for user freedom. If it proceeds with legal action, a court ruling could clarify the often-ambiguous boundaries of open-source licenses. Either way, the message is clear: the community will not tolerate being silenced by a private DM.

Source: The Verge News