Bambu Lab threatens open source fork developer for bypassing cloud

Bambu Lab, known for its popular 3D printers like the P1S, has escalated its battle against user autonomy by threatening legal action against the developer of OrcaSlicer-bambulab, a fork of the open source OrcaSlicer. OrcaSlicer itself is a fork of Bambu Studio, which is based on PrusaSlicer and Slic3r, all under the AGPLv3 license. The fork allows users to print locally without routing files through Bambu's cloud servers—a feature 0.1% of power users demand. Bambu Lab publicly accused the fork of an "impersonation attack" for injecting a user agent string that mimics the official Bambu Studio client, even though the code is derived from Bambu's own AGPL-licensed Linux software. The developer denied the claims, noting the fork uses upstream code verbatim and that Bambu refused to publish full correspondence, instead issuing a one-sided blog post that brands the developer as a security risk.

This move is the latest in Bambu Lab's ongoing friction with the open source community. Last year, the company made cloud connectivity the default, prompting users like the original blog author to block their printers from the internet, disable firmware updates, and switch to OrcaSlicer. Now, Bambu is leveraging legal threats to suppress a tiny fork that merely restores local control—exposing a fundamental tension between the AGPLv3 license's guarantee of freedom and Bambu's business model of cloud dependency. The company claims the impersonation could cause "structural vulnerability" to their servers, but critics argue that a simple user agent string is no real security measure. For professionals who value ownership of their hardware, this case is a stark reminder that open source licenses can be undermined by corporate legal power.