Bambu Lab backs off after SFC flags AGPL breaches and intimidation claims

What triggered the backlash

Bambu Lab’s slicer, Bambu Studio, is a fork of the open‑source PrusaSlicer and is distributed under the AGPL‑v3 license. In early 2024 the company introduced the Authorization Control System and a middleware plugin called Bambu Connect that forced users to route prints through Bambu’s cloud service. Independent developer Paweł Jarczak released a modified version of OrcaSlicer – a community fork of Bambu Studio – that restored full local printing and bypassed the cloud checks.

When Jarczak posted his fork on GitHub, Bambu Lab responded with a cease‑and‑desist style demand, claiming that its Terms of Service overrode the AGPL. The company also threatened legal action if the repository was not taken down. The episode drew criticism from well‑known reviewers such as Louis Rossmann and Gamers Nexus, who called the move a direct attack on open‑source rights.

SFC’s investigation and findings

The Software Freedom Conservancy (SFC) opened a formal audit after the community outcry. Their report, published on May 18, 2026, identified two distinct violations of the AGPL‑v3:

1. Undisclosed proprietary networking library – Bambu Lab ships a closed‑source component named bambu_networking inside the Bambu Studio installer. Under AGPL‑v3, any linked code must be made available in source form, which Bambu failed to do.
2. Improper restriction of downstream rights – By demanding that Jarczak remove his fork and by asserting that the company’s Terms of Service could add extra constraints, Bambu Lab contravened the license clause that forbids additional restrictions on the granted rights.

The SFC quoted the license verbatim: “You may not impose any further restrictions on the exercise of the rights granted or affirmed under this License.” Their statement can be read in full on the SFC website.

Bambu Lab’s response

Faced with mounting pressure, Bambu Lab issued a public apology, saying that references to “terms of service, legal context, and a potential C&D” were not intended as a legal threat. The company pledged to review its licensing practices and to work with the community to resolve the issues.

What the SFC is doing next

To mitigate the damage and provide a clean‑room alternative, the SFC launched the baltobu project. The effort has three main goals:

• Reverse‑engineer a replacement for bambu_networking – a fully open‑source networking stack that can be linked with Bambu Studio without violating the AGPL.
• Maintain an actively updated OrcaSlicer fork that incorporates the same cloud‑bypass features Jarczak introduced.
• Create a dedicated Bambu Studio fork that ships only open‑source components.

The fundraiser for baltobu quickly surpassed its $250,000 target, allowing the SFC to hire staff and coordinate volunteers. Details about the project and its repository are available on the SFC’s GitHub organization.

How this affects users and the 3D‑printing ecosystem

For owners of Bambu printers, the immediate impact is twofold:

• Software freedom – Users can now choose a slicer that respects the AGPL, meaning they retain the right to modify, share, and run the software on any hardware without cloud lock‑in.
• Potential firmware updates – If Bambu Lab adopts the open networking stack, future firmware releases may no longer require the proprietary middleware, simplifying the upgrade path for hobbyists.

Competitors that rely on fully open‑source toolchains, such as Prusa Research, gain a reputational edge, while Bambu Lab risks losing trust among the maker community if it does not follow through on its promises.

Who should care?

• Makers and hobbyists who rely on local printing and want to avoid vendor‑locked cloud services.
• Open‑source advocates tracking AGPL compliance across hardware vendors.
• Enterprise users evaluating Bambu printers for production; the licensing dispute may influence procurement decisions.

The episode underscores how quickly licensing oversights can turn into public relations crises, especially when a company’s business model depends on cloud‑based control. As the baltobu project gains momentum, the 3D‑printing community will have a tangible example of how to reclaim software freedom when a vendor oversteps its legal bounds.

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Sources: SFC press release, Bambu Lab official statement, GitHub – baltobu project.