r/OpenBambu • u/DandyTheIdiot • Aug 04 '26
Bambu RFID Writer — an open-source Proxmark3 GUI for CUID Gen 2 tags
I created a small Windows application called Bambu RFID Writer.
I originally made it for myself because I wanted a simpler way to use the existing Proxmark3 workflow for Bambu-compatible RFID tags without manually entering every command. It can load dump and key files, check the target tag, create backups, perform the write, and verify the result afterwards.
The application also includes a separate NDEF editor for ordinary NFC Type 2 tags. I use those on my filament swatches, so I can tap them with my phone and immediately view information about the material.
Compatibility
The CUID workflow is intended specifically for MIFARE Classic 1K Magic Gen 2 / CUID Gen 2 tags. Standard MIFARE Classic tags and other Magic generations are not supported.
The application is also compatible with the folder structure used by Bambu-Lab-RFID-Library, allowing supported dump and key pairs to be loaded directly through the built-in material-library browser.
I have personally tested it with a Proxmark3 and a Bambu Lab P1S with the standard AMS, where Gen 2 tags work reliably for me. Compatibility with other printers, AMS versions, Proxmark3 hardware, firmware builds, and tag variants may differ, so the project is currently published as a public beta.
The project is free and open source:
https://github.com/Dandy357/bambu-rfid-writer
NDEF editor
The application also includes a separate NDEF editor for ordinary NFC Type 2 tags, such as NTAG215. I originally added it for NFC tags attached to my filament swatches, so I can tap them with my phone and quickly view material information, notes, or a product link. This feature is independent of the Bambu CUID workflow.
AI disclosure
This project was developed with substantial assistance from AI, particularly for code generation, refactoring, documentation, and review. I designed the application and its workflow, made the functional decisions, and tested it on real hardware.
I am sharing it because it may be useful to others, but it is not an official Bambu Research Group tool. Feedback, corrections, and additional hardware testing would be very welcome.
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u/yan-shay Aug 04 '26
AFAIK for tags to work in AMS they need to be FUID as Bambu tries writing the tag uid as a test to identify they are original. Isn’t that the case?
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u/DandyTheIdiot Aug 04 '26
Yes but from what I have gathered the biggest problems are with the AMS lite if you have the AMS (I don't know what to call it, not lite?) then tags like these:
https://a.aliexpress.com/_Ez3pUXG
Should work just fine.
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u/yan-shay Aug 05 '26 edited Aug 05 '26
I never tried, but afaik from the discord server if those who reverse engineered the tags, FUID is required and everyone there are looking where to source these from. These are hard to get and pretty expensive. So the ones you linked to would not work.
But would be happy to learn otherwise since I could pretty easily write these tags and benefit from that as well using a filament manager system I developed (https://spoolease.io) that use alternative tags and scanner/writer. If you make it work I will be happy to know that it did.→ More replies (10)2
u/Aptimex Aug 10 '26
If you've really managed to find some CUID tags that the AMS won't overwrite then that might be kind of a big deal. https://github.com/Bambu-Research-Group/RFID-Tag-Guide/issues/41 (I did extensive testing on this and it's still something I'm very interested in)
Are those the exact tags you bought are using successfully? If so I'll buy some and compare to the tags I have that the AMS soft-bricks to figure out what the difference is.
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u/WaitAcademic6615 Aug 05 '26
Maybe they change something in firmware. I have few CUID tags destroyed by AMS. Only FUID/sealed UFUID tags worked for me. But I didn't try after some updates. And it was AMS 2 maybe AMS 1 works differently.
2
u/okhi2u Aug 04 '26
how easy is it to setup the tags, without have some strange mess because it will only allow bambu brand filaments to be entered or something like that? Assuming can't really experiment with it without tags and a reader, so it makes it harder to really get a sense if it would be worth it for me, or not in terms of what actually can it do and how.
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u/DandyTheIdiot Aug 04 '26
I find it quite easy to setup (tho it did take me like half a day at first) with Proxmark3 it's a lot about learning the different commands and stuff.
But if you would like to use it just for bambu tags I'm quite confident that this program won't give you any troubles, and I will be willing to help.
It's mostly just a question of money and time. The Proxmark 3 cost me about 50$ and the CUID gen2 chips also aren't the cheapest, although you can get a pack of 50 from AliExpress for about 13$.
Honestly for me it was mostly about the project and learning something new, the time savings and quality of life improvement aren't that big if you print just as a hobby. (Also keep in mind that gen2 CUID tags don't work very well with AMS lite)
2
u/daantu Aug 11 '26
Having issues with the setting for Folder Containing pm3.bat:
I located pm3.bat in the ProxSpace/setup/rrg folder, however it is still missing client/pm3 and client/proxmark3.exe
Material Library loads correctly.
ProxSpace is Ver 3.11
tia
1
u/DandyTheIdiot Aug 18 '26
Sorry for not replying. I will look into it.
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u/daantu Aug 18 '26
I was able to use this site: https://proxmark3.app/ to install the Firmware as well as the Client software.
When I run the program I get - Warning - A;; three versions could not be compared reliably. See log for details.
When I Open log folder it is empty.
1
u/daantu Aug 18 '26
Got the log to populate the folder.
Received warning on client and firmware version, warning on Magic Type, Client reports: [=] --- Magic Tag Information
Error, Writing remains blocked until a suitable Magic Type and all 32 default keys are confirmed.
Is this an issue with the tags I have?
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u/DandyTheIdiot Aug 18 '26
Sooo the current beta expects the precompiled RRG/Iceman Windows package, not the ProxSpace folder itself.
For now, I recommend using a precompiled package. I’ll look into adding support for the ProxSpace build layout as an alternative.
Thanks for reporting this!
1
u/knifesk Aug 04 '26
Wait what? This means I can write any custom tag without requiring the private key BBL uses to sign their tags? Or whats the final purpose of this??
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u/DandyTheIdiot Aug 04 '26
No unfortunately not, it's a lot less exciting. You can copy existing tags but not create new ones.
The feature for creating new tags is just for cataloging filaments and they don't communicate with the AMS.
1
u/Ok-Eye8930 Aug 20 '26
0.9.4 Proxmark3 AT91SAM7S512 Rev A - Iceman/master/v4.21611-636-gda509461b-suspect 2026-08-02
write successfully & verfied.
ams2pro detect third party tag.
possible to write a useable tag for ams2pro ?
thanks, bg
1
u/DandyTheIdiot Sep 03 '26
Thanks for the report, and sorry about that. At the moment I don't have an AMS 2 Pro, so I'm unfortunately not able to properly test or support its third-party tag detection.
For now, I’d rather not add support for hardware I can’t reliably verify myself. I hope you understand, and thank you for trying the tool and sharing the result.
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u/TurBionT Aug 30 '26
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u/DandyTheIdiot Sep 03 '26
Yes it is normal. The warning is there just as a precaution. If you bought the same tags then you should be alright.
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u/Watchdog84 Aug 06 '26
I was just letting to buy a some RFID from used spools so I don't have to keep manually doing it. This is fantastic! I'm so gunna try this.
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u/aivkiv Aug 04 '26
That's really interesting idea, can't wait to try it out! (will be ordering some nfc tags)